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1) We should not try to simplify if the sext has multiple uses 2) There is no need to simplify is the source value is already sign-extended. Patch by Gil Rapaport <gil.rapaport@intel.com> Differential Revision: http://reviews.llvm.org/D6949 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229659 91177308-0d34-0410-b5e6-96231b3b80d8
2968 lines
120 KiB
C++
2968 lines
120 KiB
C++
//===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This implements the TargetLowering class.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Target/TargetLowering.h"
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#include "llvm/ADT/BitVector.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/CodeGen/Analysis.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineJumpTableInfo.h"
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#include "llvm/CodeGen/SelectionDAG.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/GlobalVariable.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Target/TargetLoweringObjectFile.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetRegisterInfo.h"
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#include "llvm/Target/TargetSubtargetInfo.h"
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#include <cctype>
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using namespace llvm;
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/// NOTE: The TargetMachine owns TLOF.
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TargetLowering::TargetLowering(const TargetMachine &tm)
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: TargetLoweringBase(tm) {}
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const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
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return nullptr;
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}
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/// Check whether a given call node is in tail position within its function. If
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/// so, it sets Chain to the input chain of the tail call.
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bool TargetLowering::isInTailCallPosition(SelectionDAG &DAG, SDNode *Node,
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SDValue &Chain) const {
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const Function *F = DAG.getMachineFunction().getFunction();
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// Conservatively require the attributes of the call to match those of
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// the return. Ignore noalias because it doesn't affect the call sequence.
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AttributeSet CallerAttrs = F->getAttributes();
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if (AttrBuilder(CallerAttrs, AttributeSet::ReturnIndex)
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.removeAttribute(Attribute::NoAlias).hasAttributes())
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return false;
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// It's not safe to eliminate the sign / zero extension of the return value.
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if (CallerAttrs.hasAttribute(AttributeSet::ReturnIndex, Attribute::ZExt) ||
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CallerAttrs.hasAttribute(AttributeSet::ReturnIndex, Attribute::SExt))
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return false;
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// Check if the only use is a function return node.
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return isUsedByReturnOnly(Node, Chain);
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}
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/// \brief Set CallLoweringInfo attribute flags based on a call instruction
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/// and called function attributes.
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void TargetLowering::ArgListEntry::setAttributes(ImmutableCallSite *CS,
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unsigned AttrIdx) {
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isSExt = CS->paramHasAttr(AttrIdx, Attribute::SExt);
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isZExt = CS->paramHasAttr(AttrIdx, Attribute::ZExt);
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isInReg = CS->paramHasAttr(AttrIdx, Attribute::InReg);
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isSRet = CS->paramHasAttr(AttrIdx, Attribute::StructRet);
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isNest = CS->paramHasAttr(AttrIdx, Attribute::Nest);
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isByVal = CS->paramHasAttr(AttrIdx, Attribute::ByVal);
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isInAlloca = CS->paramHasAttr(AttrIdx, Attribute::InAlloca);
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isReturned = CS->paramHasAttr(AttrIdx, Attribute::Returned);
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Alignment = CS->getParamAlignment(AttrIdx);
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}
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/// Generate a libcall taking the given operands as arguments and returning a
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/// result of type RetVT.
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std::pair<SDValue, SDValue>
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TargetLowering::makeLibCall(SelectionDAG &DAG,
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RTLIB::Libcall LC, EVT RetVT,
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const SDValue *Ops, unsigned NumOps,
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bool isSigned, SDLoc dl,
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bool doesNotReturn,
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bool isReturnValueUsed) const {
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TargetLowering::ArgListTy Args;
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Args.reserve(NumOps);
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TargetLowering::ArgListEntry Entry;
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for (unsigned i = 0; i != NumOps; ++i) {
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Entry.Node = Ops[i];
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Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
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Entry.isSExt = isSigned;
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Entry.isZExt = !isSigned;
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Args.push_back(Entry);
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}
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SDValue Callee = DAG.getExternalSymbol(getLibcallName(LC), getPointerTy());
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Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
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TargetLowering::CallLoweringInfo CLI(DAG);
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CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
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.setCallee(getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0)
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.setNoReturn(doesNotReturn).setDiscardResult(!isReturnValueUsed)
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.setSExtResult(isSigned).setZExtResult(!isSigned);
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return LowerCallTo(CLI);
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}
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/// SoftenSetCCOperands - Soften the operands of a comparison. This code is
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/// shared among BR_CC, SELECT_CC, and SETCC handlers.
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void TargetLowering::softenSetCCOperands(SelectionDAG &DAG, EVT VT,
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SDValue &NewLHS, SDValue &NewRHS,
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ISD::CondCode &CCCode,
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SDLoc dl) const {
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assert((VT == MVT::f32 || VT == MVT::f64 || VT == MVT::f128)
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&& "Unsupported setcc type!");
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// Expand into one or more soft-fp libcall(s).
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RTLIB::Libcall LC1 = RTLIB::UNKNOWN_LIBCALL, LC2 = RTLIB::UNKNOWN_LIBCALL;
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switch (CCCode) {
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case ISD::SETEQ:
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case ISD::SETOEQ:
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LC1 = (VT == MVT::f32) ? RTLIB::OEQ_F32 :
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(VT == MVT::f64) ? RTLIB::OEQ_F64 : RTLIB::OEQ_F128;
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break;
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case ISD::SETNE:
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case ISD::SETUNE:
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LC1 = (VT == MVT::f32) ? RTLIB::UNE_F32 :
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(VT == MVT::f64) ? RTLIB::UNE_F64 : RTLIB::UNE_F128;
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break;
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case ISD::SETGE:
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case ISD::SETOGE:
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LC1 = (VT == MVT::f32) ? RTLIB::OGE_F32 :
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(VT == MVT::f64) ? RTLIB::OGE_F64 : RTLIB::OGE_F128;
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break;
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case ISD::SETLT:
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case ISD::SETOLT:
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LC1 = (VT == MVT::f32) ? RTLIB::OLT_F32 :
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(VT == MVT::f64) ? RTLIB::OLT_F64 : RTLIB::OLT_F128;
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break;
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case ISD::SETLE:
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case ISD::SETOLE:
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LC1 = (VT == MVT::f32) ? RTLIB::OLE_F32 :
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(VT == MVT::f64) ? RTLIB::OLE_F64 : RTLIB::OLE_F128;
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break;
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case ISD::SETGT:
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case ISD::SETOGT:
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LC1 = (VT == MVT::f32) ? RTLIB::OGT_F32 :
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(VT == MVT::f64) ? RTLIB::OGT_F64 : RTLIB::OGT_F128;
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break;
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case ISD::SETUO:
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LC1 = (VT == MVT::f32) ? RTLIB::UO_F32 :
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(VT == MVT::f64) ? RTLIB::UO_F64 : RTLIB::UO_F128;
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break;
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case ISD::SETO:
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LC1 = (VT == MVT::f32) ? RTLIB::O_F32 :
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(VT == MVT::f64) ? RTLIB::O_F64 : RTLIB::O_F128;
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break;
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default:
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LC1 = (VT == MVT::f32) ? RTLIB::UO_F32 :
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(VT == MVT::f64) ? RTLIB::UO_F64 : RTLIB::UO_F128;
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switch (CCCode) {
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case ISD::SETONE:
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// SETONE = SETOLT | SETOGT
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LC1 = (VT == MVT::f32) ? RTLIB::OLT_F32 :
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(VT == MVT::f64) ? RTLIB::OLT_F64 : RTLIB::OLT_F128;
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// Fallthrough
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case ISD::SETUGT:
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LC2 = (VT == MVT::f32) ? RTLIB::OGT_F32 :
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(VT == MVT::f64) ? RTLIB::OGT_F64 : RTLIB::OGT_F128;
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break;
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case ISD::SETUGE:
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LC2 = (VT == MVT::f32) ? RTLIB::OGE_F32 :
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(VT == MVT::f64) ? RTLIB::OGE_F64 : RTLIB::OGE_F128;
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break;
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case ISD::SETULT:
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LC2 = (VT == MVT::f32) ? RTLIB::OLT_F32 :
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(VT == MVT::f64) ? RTLIB::OLT_F64 : RTLIB::OLT_F128;
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break;
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case ISD::SETULE:
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LC2 = (VT == MVT::f32) ? RTLIB::OLE_F32 :
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(VT == MVT::f64) ? RTLIB::OLE_F64 : RTLIB::OLE_F128;
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break;
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case ISD::SETUEQ:
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LC2 = (VT == MVT::f32) ? RTLIB::OEQ_F32 :
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(VT == MVT::f64) ? RTLIB::OEQ_F64 : RTLIB::OEQ_F128;
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break;
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default: llvm_unreachable("Do not know how to soften this setcc!");
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}
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}
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// Use the target specific return value for comparions lib calls.
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EVT RetVT = getCmpLibcallReturnType();
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SDValue Ops[2] = { NewLHS, NewRHS };
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NewLHS = makeLibCall(DAG, LC1, RetVT, Ops, 2, false/*sign irrelevant*/,
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dl).first;
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NewRHS = DAG.getConstant(0, RetVT);
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CCCode = getCmpLibcallCC(LC1);
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if (LC2 != RTLIB::UNKNOWN_LIBCALL) {
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SDValue Tmp = DAG.getNode(ISD::SETCC, dl,
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getSetCCResultType(*DAG.getContext(), RetVT),
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NewLHS, NewRHS, DAG.getCondCode(CCCode));
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NewLHS = makeLibCall(DAG, LC2, RetVT, Ops, 2, false/*sign irrelevant*/,
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dl).first;
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NewLHS = DAG.getNode(ISD::SETCC, dl,
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getSetCCResultType(*DAG.getContext(), RetVT), NewLHS,
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NewRHS, DAG.getCondCode(getCmpLibcallCC(LC2)));
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NewLHS = DAG.getNode(ISD::OR, dl, Tmp.getValueType(), Tmp, NewLHS);
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NewRHS = SDValue();
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}
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}
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/// getJumpTableEncoding - Return the entry encoding for a jump table in the
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/// current function. The returned value is a member of the
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/// MachineJumpTableInfo::JTEntryKind enum.
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unsigned TargetLowering::getJumpTableEncoding() const {
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// In non-pic modes, just use the address of a block.
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if (getTargetMachine().getRelocationModel() != Reloc::PIC_)
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return MachineJumpTableInfo::EK_BlockAddress;
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// In PIC mode, if the target supports a GPRel32 directive, use it.
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if (getTargetMachine().getMCAsmInfo()->getGPRel32Directive() != nullptr)
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return MachineJumpTableInfo::EK_GPRel32BlockAddress;
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// Otherwise, use a label difference.
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return MachineJumpTableInfo::EK_LabelDifference32;
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}
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SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
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SelectionDAG &DAG) const {
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// If our PIC model is GP relative, use the global offset table as the base.
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unsigned JTEncoding = getJumpTableEncoding();
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if ((JTEncoding == MachineJumpTableInfo::EK_GPRel64BlockAddress) ||
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(JTEncoding == MachineJumpTableInfo::EK_GPRel32BlockAddress))
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return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy(0));
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return Table;
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}
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/// getPICJumpTableRelocBaseExpr - This returns the relocation base for the
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/// given PIC jumptable, the same as getPICJumpTableRelocBase, but as an
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/// MCExpr.
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const MCExpr *
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TargetLowering::getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
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unsigned JTI,MCContext &Ctx) const{
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// The normal PIC reloc base is the label at the start of the jump table.
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return MCSymbolRefExpr::Create(MF->getJTISymbol(JTI, Ctx), Ctx);
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}
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bool
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TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
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// Assume that everything is safe in static mode.
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if (getTargetMachine().getRelocationModel() == Reloc::Static)
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return true;
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// In dynamic-no-pic mode, assume that known defined values are safe.
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if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC &&
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GA &&
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!GA->getGlobal()->isDeclaration() &&
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!GA->getGlobal()->isWeakForLinker())
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return true;
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// Otherwise assume nothing is safe.
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return false;
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}
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//===----------------------------------------------------------------------===//
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// Optimization Methods
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//===----------------------------------------------------------------------===//
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/// ShrinkDemandedConstant - Check to see if the specified operand of the
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/// specified instruction is a constant integer. If so, check to see if there
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/// are any bits set in the constant that are not demanded. If so, shrink the
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/// constant and return true.
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bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDValue Op,
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const APInt &Demanded) {
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SDLoc dl(Op);
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// FIXME: ISD::SELECT, ISD::SELECT_CC
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switch (Op.getOpcode()) {
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default: break;
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case ISD::XOR:
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case ISD::AND:
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case ISD::OR: {
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ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
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if (!C) return false;
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if (Op.getOpcode() == ISD::XOR &&
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(C->getAPIntValue() | (~Demanded)).isAllOnesValue())
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return false;
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// if we can expand it to have all bits set, do it
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if (C->getAPIntValue().intersects(~Demanded)) {
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EVT VT = Op.getValueType();
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SDValue New = DAG.getNode(Op.getOpcode(), dl, VT, Op.getOperand(0),
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DAG.getConstant(Demanded &
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C->getAPIntValue(),
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VT));
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return CombineTo(Op, New);
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}
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break;
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}
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}
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return false;
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}
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/// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the
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/// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening
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/// cast, but it could be generalized for targets with other types of
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/// implicit widening casts.
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bool
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TargetLowering::TargetLoweringOpt::ShrinkDemandedOp(SDValue Op,
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unsigned BitWidth,
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const APInt &Demanded,
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SDLoc dl) {
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assert(Op.getNumOperands() == 2 &&
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"ShrinkDemandedOp only supports binary operators!");
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assert(Op.getNode()->getNumValues() == 1 &&
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"ShrinkDemandedOp only supports nodes with one result!");
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// Early return, as this function cannot handle vector types.
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if (Op.getValueType().isVector())
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return false;
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// Don't do this if the node has another user, which may require the
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// full value.
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if (!Op.getNode()->hasOneUse())
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return false;
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// Search for the smallest integer type with free casts to and from
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// Op's type. For expedience, just check power-of-2 integer types.
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const TargetLowering &TLI = DAG.getTargetLoweringInfo();
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unsigned DemandedSize = BitWidth - Demanded.countLeadingZeros();
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unsigned SmallVTBits = DemandedSize;
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if (!isPowerOf2_32(SmallVTBits))
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SmallVTBits = NextPowerOf2(SmallVTBits);
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for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) {
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EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), SmallVTBits);
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if (TLI.isTruncateFree(Op.getValueType(), SmallVT) &&
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TLI.isZExtFree(SmallVT, Op.getValueType())) {
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// We found a type with free casts.
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SDValue X = DAG.getNode(Op.getOpcode(), dl, SmallVT,
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DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
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Op.getNode()->getOperand(0)),
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DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
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Op.getNode()->getOperand(1)));
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bool NeedZext = DemandedSize > SmallVTBits;
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SDValue Z = DAG.getNode(NeedZext ? ISD::ZERO_EXTEND : ISD::ANY_EXTEND,
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dl, Op.getValueType(), X);
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return CombineTo(Op, Z);
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}
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}
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return false;
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}
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/// SimplifyDemandedBits - Look at Op. At this point, we know that only the
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/// DemandedMask bits of the result of Op are ever used downstream. If we can
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/// use this information to simplify Op, create a new simplified DAG node and
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/// return true, returning the original and new nodes in Old and New. Otherwise,
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/// analyze the expression and return a mask of KnownOne and KnownZero bits for
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/// the expression (used to simplify the caller). The KnownZero/One bits may
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/// only be accurate for those bits in the DemandedMask.
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bool TargetLowering::SimplifyDemandedBits(SDValue Op,
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const APInt &DemandedMask,
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APInt &KnownZero,
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APInt &KnownOne,
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TargetLoweringOpt &TLO,
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unsigned Depth) const {
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unsigned BitWidth = DemandedMask.getBitWidth();
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assert(Op.getValueType().getScalarType().getSizeInBits() == BitWidth &&
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"Mask size mismatches value type size!");
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APInt NewMask = DemandedMask;
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SDLoc dl(Op);
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// Don't know anything.
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KnownZero = KnownOne = APInt(BitWidth, 0);
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// Other users may use these bits.
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if (!Op.getNode()->hasOneUse()) {
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if (Depth != 0) {
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// If not at the root, Just compute the KnownZero/KnownOne bits to
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// simplify things downstream.
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TLO.DAG.computeKnownBits(Op, KnownZero, KnownOne, Depth);
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return false;
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}
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// If this is the root being simplified, allow it to have multiple uses,
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// just set the NewMask to all bits.
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NewMask = APInt::getAllOnesValue(BitWidth);
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} else if (DemandedMask == 0) {
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// Not demanding any bits from Op.
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if (Op.getOpcode() != ISD::UNDEF)
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return TLO.CombineTo(Op, TLO.DAG.getUNDEF(Op.getValueType()));
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return false;
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} else if (Depth == 6) { // Limit search depth.
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return false;
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}
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APInt KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut;
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switch (Op.getOpcode()) {
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case ISD::Constant:
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// We know all of the bits for a constant!
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KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue();
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KnownZero = ~KnownOne;
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return false; // Don't fall through, will infinitely loop.
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case ISD::AND:
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// If the RHS is a constant, check to see if the LHS would be zero without
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// using the bits from the RHS. Below, we use knowledge about the RHS to
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// simplify the LHS, here we're using information from the LHS to simplify
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// the RHS.
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if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
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|
APInt LHSZero, LHSOne;
|
|
// Do not increment Depth here; that can cause an infinite loop.
|
|
TLO.DAG.computeKnownBits(Op.getOperand(0), LHSZero, LHSOne, Depth);
|
|
// If the LHS already has zeros where RHSC does, this and is dead.
|
|
if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(0));
|
|
// If any of the set bits in the RHS are known zero on the LHS, shrink
|
|
// the constant.
|
|
if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & NewMask))
|
|
return true;
|
|
}
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
|
|
KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
if (SimplifyDemandedBits(Op.getOperand(0), ~KnownZero & NewMask,
|
|
KnownZero2, KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
|
|
|
|
// If all of the demanded bits are known one on one side, return the other.
|
|
// These bits cannot contribute to the result of the 'and'.
|
|
if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(0));
|
|
if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(1));
|
|
// If all of the demanded bits in the inputs are known zeros, return zero.
|
|
if ((NewMask & (KnownZero|KnownZero2)) == NewMask)
|
|
return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType()));
|
|
// If the RHS is a constant, see if we can simplify it.
|
|
if (TLO.ShrinkDemandedConstant(Op, ~KnownZero2 & NewMask))
|
|
return true;
|
|
// If the operation can be done in a smaller type, do so.
|
|
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
|
|
return true;
|
|
|
|
// Output known-1 bits are only known if set in both the LHS & RHS.
|
|
KnownOne &= KnownOne2;
|
|
// Output known-0 are known to be clear if zero in either the LHS | RHS.
|
|
KnownZero |= KnownZero2;
|
|
break;
|
|
case ISD::OR:
|
|
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
|
|
KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask,
|
|
KnownZero2, KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
|
|
|
|
// If all of the demanded bits are known zero on one side, return the other.
|
|
// These bits cannot contribute to the result of the 'or'.
|
|
if ((NewMask & ~KnownOne2 & KnownZero) == (~KnownOne2 & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(0));
|
|
if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(1));
|
|
// If all of the potentially set bits on one side are known to be set on
|
|
// the other side, just use the 'other' side.
|
|
if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(0));
|
|
if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
|
|
return TLO.CombineTo(Op, Op.getOperand(1));
|
|
// If the RHS is a constant, see if we can simplify it.
|
|
if (TLO.ShrinkDemandedConstant(Op, NewMask))
|
|
return true;
|
|
// If the operation can be done in a smaller type, do so.
|
|
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
|
|
return true;
|
|
|
|
// Output known-0 bits are only known if clear in both the LHS & RHS.
|
|
KnownZero &= KnownZero2;
|
|
// Output known-1 are known to be set if set in either the LHS | RHS.
|
|
KnownOne |= KnownOne2;
|
|
break;
|
|
case ISD::XOR:
|
|
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
|
|
KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
if (SimplifyDemandedBits(Op.getOperand(0), NewMask, KnownZero2,
|
|
KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
|
|
|
|
// If all of the demanded bits are known zero on one side, return the other.
|
|
// These bits cannot contribute to the result of the 'xor'.
|
|
if ((KnownZero & NewMask) == NewMask)
|
|
return TLO.CombineTo(Op, Op.getOperand(0));
|
|
if ((KnownZero2 & NewMask) == NewMask)
|
|
return TLO.CombineTo(Op, Op.getOperand(1));
|
|
// If the operation can be done in a smaller type, do so.
|
|
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
|
|
return true;
|
|
|
|
// If all of the unknown bits are known to be zero on one side or the other
|
|
// (but not both) turn this into an *inclusive* or.
|
|
// e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
|
|
if ((NewMask & ~KnownZero & ~KnownZero2) == 0)
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(),
|
|
Op.getOperand(0),
|
|
Op.getOperand(1)));
|
|
|
|
// Output known-0 bits are known if clear or set in both the LHS & RHS.
|
|
KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
|
|
// Output known-1 are known to be set if set in only one of the LHS, RHS.
|
|
KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
|
|
|
|
// If all of the demanded bits on one side are known, and all of the set
|
|
// bits on that side are also known to be set on the other side, turn this
|
|
// into an AND, as we know the bits will be cleared.
|
|
// e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
|
|
// NB: it is okay if more bits are known than are requested
|
|
if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known on one side
|
|
if (KnownOne == KnownOne2) { // set bits are the same on both sides
|
|
EVT VT = Op.getValueType();
|
|
SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT);
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT,
|
|
Op.getOperand(0), ANDC));
|
|
}
|
|
}
|
|
|
|
// If the RHS is a constant, see if we can simplify it.
|
|
// for XOR, we prefer to force bits to 1 if they will make a -1.
|
|
// if we can't force bits, try to shrink constant
|
|
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
|
|
APInt Expanded = C->getAPIntValue() | (~NewMask);
|
|
// if we can expand it to have all bits set, do it
|
|
if (Expanded.isAllOnesValue()) {
|
|
if (Expanded != C->getAPIntValue()) {
|
|
EVT VT = Op.getValueType();
|
|
SDValue New = TLO.DAG.getNode(Op.getOpcode(), dl,VT, Op.getOperand(0),
|
|
TLO.DAG.getConstant(Expanded, VT));
|
|
return TLO.CombineTo(Op, New);
|
|
}
|
|
// if it already has all the bits set, nothing to change
|
|
// but don't shrink either!
|
|
} else if (TLO.ShrinkDemandedConstant(Op, NewMask)) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
KnownZero = KnownZeroOut;
|
|
KnownOne = KnownOneOut;
|
|
break;
|
|
case ISD::SELECT:
|
|
if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero,
|
|
KnownOne, TLO, Depth+1))
|
|
return true;
|
|
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero2,
|
|
KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
|
|
|
|
// If the operands are constants, see if we can simplify them.
|
|
if (TLO.ShrinkDemandedConstant(Op, NewMask))
|
|
return true;
|
|
|
|
// Only known if known in both the LHS and RHS.
|
|
KnownOne &= KnownOne2;
|
|
KnownZero &= KnownZero2;
|
|
break;
|
|
case ISD::SELECT_CC:
|
|
if (SimplifyDemandedBits(Op.getOperand(3), NewMask, KnownZero,
|
|
KnownOne, TLO, Depth+1))
|
|
return true;
|
|
if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero2,
|
|
KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
|
|
|
|
// If the operands are constants, see if we can simplify them.
|
|
if (TLO.ShrinkDemandedConstant(Op, NewMask))
|
|
return true;
|
|
|
|
// Only known if known in both the LHS and RHS.
|
|
KnownOne &= KnownOne2;
|
|
KnownZero &= KnownZero2;
|
|
break;
|
|
case ISD::SHL:
|
|
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
|
|
unsigned ShAmt = SA->getZExtValue();
|
|
SDValue InOp = Op.getOperand(0);
|
|
|
|
// If the shift count is an invalid immediate, don't do anything.
|
|
if (ShAmt >= BitWidth)
|
|
break;
|
|
|
|
// If this is ((X >>u C1) << ShAmt), see if we can simplify this into a
|
|
// single shift. We can do this if the bottom bits (which are shifted
|
|
// out) are never demanded.
|
|
if (InOp.getOpcode() == ISD::SRL &&
|
|
isa<ConstantSDNode>(InOp.getOperand(1))) {
|
|
if (ShAmt && (NewMask & APInt::getLowBitsSet(BitWidth, ShAmt)) == 0) {
|
|
unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
|
|
unsigned Opc = ISD::SHL;
|
|
int Diff = ShAmt-C1;
|
|
if (Diff < 0) {
|
|
Diff = -Diff;
|
|
Opc = ISD::SRL;
|
|
}
|
|
|
|
SDValue NewSA =
|
|
TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
|
|
EVT VT = Op.getValueType();
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
|
|
InOp.getOperand(0), NewSA));
|
|
}
|
|
}
|
|
|
|
if (SimplifyDemandedBits(InOp, NewMask.lshr(ShAmt),
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
|
|
// Convert (shl (anyext x, c)) to (anyext (shl x, c)) if the high bits
|
|
// are not demanded. This will likely allow the anyext to be folded away.
|
|
if (InOp.getNode()->getOpcode() == ISD::ANY_EXTEND) {
|
|
SDValue InnerOp = InOp.getNode()->getOperand(0);
|
|
EVT InnerVT = InnerOp.getValueType();
|
|
unsigned InnerBits = InnerVT.getSizeInBits();
|
|
if (ShAmt < InnerBits && NewMask.lshr(InnerBits) == 0 &&
|
|
isTypeDesirableForOp(ISD::SHL, InnerVT)) {
|
|
EVT ShTy = getShiftAmountTy(InnerVT);
|
|
if (!APInt(BitWidth, ShAmt).isIntN(ShTy.getSizeInBits()))
|
|
ShTy = InnerVT;
|
|
SDValue NarrowShl =
|
|
TLO.DAG.getNode(ISD::SHL, dl, InnerVT, InnerOp,
|
|
TLO.DAG.getConstant(ShAmt, ShTy));
|
|
return
|
|
TLO.CombineTo(Op,
|
|
TLO.DAG.getNode(ISD::ANY_EXTEND, dl, Op.getValueType(),
|
|
NarrowShl));
|
|
}
|
|
// Repeat the SHL optimization above in cases where an extension
|
|
// intervenes: (shl (anyext (shr x, c1)), c2) to
|
|
// (shl (anyext x), c2-c1). This requires that the bottom c1 bits
|
|
// aren't demanded (as above) and that the shifted upper c1 bits of
|
|
// x aren't demanded.
|
|
if (InOp.hasOneUse() &&
|
|
InnerOp.getOpcode() == ISD::SRL &&
|
|
InnerOp.hasOneUse() &&
|
|
isa<ConstantSDNode>(InnerOp.getOperand(1))) {
|
|
uint64_t InnerShAmt = cast<ConstantSDNode>(InnerOp.getOperand(1))
|
|
->getZExtValue();
|
|
if (InnerShAmt < ShAmt &&
|
|
InnerShAmt < InnerBits &&
|
|
NewMask.lshr(InnerBits - InnerShAmt + ShAmt) == 0 &&
|
|
NewMask.trunc(ShAmt) == 0) {
|
|
SDValue NewSA =
|
|
TLO.DAG.getConstant(ShAmt - InnerShAmt,
|
|
Op.getOperand(1).getValueType());
|
|
EVT VT = Op.getValueType();
|
|
SDValue NewExt = TLO.DAG.getNode(ISD::ANY_EXTEND, dl, VT,
|
|
InnerOp.getOperand(0));
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, dl, VT,
|
|
NewExt, NewSA));
|
|
}
|
|
}
|
|
}
|
|
|
|
KnownZero <<= SA->getZExtValue();
|
|
KnownOne <<= SA->getZExtValue();
|
|
// low bits known zero.
|
|
KnownZero |= APInt::getLowBitsSet(BitWidth, SA->getZExtValue());
|
|
}
|
|
break;
|
|
case ISD::SRL:
|
|
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
|
|
EVT VT = Op.getValueType();
|
|
unsigned ShAmt = SA->getZExtValue();
|
|
unsigned VTSize = VT.getSizeInBits();
|
|
SDValue InOp = Op.getOperand(0);
|
|
|
|
// If the shift count is an invalid immediate, don't do anything.
|
|
if (ShAmt >= BitWidth)
|
|
break;
|
|
|
|
// If this is ((X << C1) >>u ShAmt), see if we can simplify this into a
|
|
// single shift. We can do this if the top bits (which are shifted out)
|
|
// are never demanded.
|
|
if (InOp.getOpcode() == ISD::SHL &&
|
|
isa<ConstantSDNode>(InOp.getOperand(1))) {
|
|
if (ShAmt && (NewMask & APInt::getHighBitsSet(VTSize, ShAmt)) == 0) {
|
|
unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
|
|
unsigned Opc = ISD::SRL;
|
|
int Diff = ShAmt-C1;
|
|
if (Diff < 0) {
|
|
Diff = -Diff;
|
|
Opc = ISD::SHL;
|
|
}
|
|
|
|
SDValue NewSA =
|
|
TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
|
|
InOp.getOperand(0), NewSA));
|
|
}
|
|
}
|
|
|
|
// Compute the new bits that are at the top now.
|
|
if (SimplifyDemandedBits(InOp, (NewMask << ShAmt),
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
KnownZero = KnownZero.lshr(ShAmt);
|
|
KnownOne = KnownOne.lshr(ShAmt);
|
|
|
|
APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
|
|
KnownZero |= HighBits; // High bits known zero.
|
|
}
|
|
break;
|
|
case ISD::SRA:
|
|
// If this is an arithmetic shift right and only the low-bit is set, we can
|
|
// always convert this into a logical shr, even if the shift amount is
|
|
// variable. The low bit of the shift cannot be an input sign bit unless
|
|
// the shift amount is >= the size of the datatype, which is undefined.
|
|
if (NewMask == 1)
|
|
return TLO.CombineTo(Op,
|
|
TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(),
|
|
Op.getOperand(0), Op.getOperand(1)));
|
|
|
|
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
|
|
EVT VT = Op.getValueType();
|
|
unsigned ShAmt = SA->getZExtValue();
|
|
|
|
// If the shift count is an invalid immediate, don't do anything.
|
|
if (ShAmt >= BitWidth)
|
|
break;
|
|
|
|
APInt InDemandedMask = (NewMask << ShAmt);
|
|
|
|
// If any of the demanded bits are produced by the sign extension, we also
|
|
// demand the input sign bit.
|
|
APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
|
|
if (HighBits.intersects(NewMask))
|
|
InDemandedMask |= APInt::getSignBit(VT.getScalarType().getSizeInBits());
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask,
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
KnownZero = KnownZero.lshr(ShAmt);
|
|
KnownOne = KnownOne.lshr(ShAmt);
|
|
|
|
// Handle the sign bit, adjusted to where it is now in the mask.
|
|
APInt SignBit = APInt::getSignBit(BitWidth).lshr(ShAmt);
|
|
|
|
// If the input sign bit is known to be zero, or if none of the top bits
|
|
// are demanded, turn this into an unsigned shift right.
|
|
if (KnownZero.intersects(SignBit) || (HighBits & ~NewMask) == HighBits)
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT,
|
|
Op.getOperand(0),
|
|
Op.getOperand(1)));
|
|
|
|
int Log2 = NewMask.exactLogBase2();
|
|
if (Log2 >= 0) {
|
|
// The bit must come from the sign.
|
|
SDValue NewSA =
|
|
TLO.DAG.getConstant(BitWidth - 1 - Log2,
|
|
Op.getOperand(1).getValueType());
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT,
|
|
Op.getOperand(0), NewSA));
|
|
}
|
|
|
|
if (KnownOne.intersects(SignBit))
|
|
// New bits are known one.
|
|
KnownOne |= HighBits;
|
|
}
|
|
break;
|
|
case ISD::SIGN_EXTEND_INREG: {
|
|
EVT ExVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
|
|
|
|
APInt MsbMask = APInt::getHighBitsSet(BitWidth, 1);
|
|
// If we only care about the highest bit, don't bother shifting right.
|
|
if (MsbMask == NewMask) {
|
|
unsigned ShAmt = ExVT.getScalarType().getSizeInBits();
|
|
SDValue InOp = Op.getOperand(0);
|
|
unsigned VTBits = Op->getValueType(0).getScalarType().getSizeInBits();
|
|
bool AlreadySignExtended =
|
|
TLO.DAG.ComputeNumSignBits(InOp) >= VTBits-ShAmt+1;
|
|
// However if the input is already sign extended we expect the sign
|
|
// extension to be dropped altogether later and do not simplify.
|
|
if (!AlreadySignExtended) {
|
|
// Compute the correct shift amount type, which must be getShiftAmountTy
|
|
// for scalar types after legalization.
|
|
EVT ShiftAmtTy = Op.getValueType();
|
|
if (TLO.LegalTypes() && !ShiftAmtTy.isVector())
|
|
ShiftAmtTy = getShiftAmountTy(ShiftAmtTy);
|
|
|
|
SDValue ShiftAmt = TLO.DAG.getConstant(BitWidth - ShAmt, ShiftAmtTy);
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, dl,
|
|
Op.getValueType(), InOp,
|
|
ShiftAmt));
|
|
}
|
|
}
|
|
|
|
// Sign extension. Compute the demanded bits in the result that are not
|
|
// present in the input.
|
|
APInt NewBits =
|
|
APInt::getHighBitsSet(BitWidth,
|
|
BitWidth - ExVT.getScalarType().getSizeInBits());
|
|
|
|
// If none of the extended bits are demanded, eliminate the sextinreg.
|
|
if ((NewBits & NewMask) == 0)
|
|
return TLO.CombineTo(Op, Op.getOperand(0));
|
|
|
|
APInt InSignBit =
|
|
APInt::getSignBit(ExVT.getScalarType().getSizeInBits()).zext(BitWidth);
|
|
APInt InputDemandedBits =
|
|
APInt::getLowBitsSet(BitWidth,
|
|
ExVT.getScalarType().getSizeInBits()) &
|
|
NewMask;
|
|
|
|
// Since the sign extended bits are demanded, we know that the sign
|
|
// bit is demanded.
|
|
InputDemandedBits |= InSignBit;
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
|
|
// If the sign bit of the input is known set or clear, then we know the
|
|
// top bits of the result.
|
|
|
|
// If the input sign bit is known zero, convert this into a zero extension.
|
|
if (KnownZero.intersects(InSignBit))
|
|
return TLO.CombineTo(Op,
|
|
TLO.DAG.getZeroExtendInReg(Op.getOperand(0),dl,ExVT));
|
|
|
|
if (KnownOne.intersects(InSignBit)) { // Input sign bit known set
|
|
KnownOne |= NewBits;
|
|
KnownZero &= ~NewBits;
|
|
} else { // Input sign bit unknown
|
|
KnownZero &= ~NewBits;
|
|
KnownOne &= ~NewBits;
|
|
}
|
|
break;
|
|
}
|
|
case ISD::BUILD_PAIR: {
|
|
EVT HalfVT = Op.getOperand(0).getValueType();
|
|
unsigned HalfBitWidth = HalfVT.getScalarSizeInBits();
|
|
|
|
APInt MaskLo = NewMask.getLoBits(HalfBitWidth).trunc(HalfBitWidth);
|
|
APInt MaskHi = NewMask.getHiBits(HalfBitWidth).trunc(HalfBitWidth);
|
|
|
|
APInt KnownZeroLo, KnownOneLo;
|
|
APInt KnownZeroHi, KnownOneHi;
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(0), MaskLo, KnownZeroLo,
|
|
KnownOneLo, TLO, Depth + 1))
|
|
return true;
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(1), MaskHi, KnownZeroHi,
|
|
KnownOneHi, TLO, Depth + 1))
|
|
return true;
|
|
|
|
KnownZero = KnownZeroLo.zext(BitWidth) |
|
|
KnownZeroHi.zext(BitWidth).shl(HalfBitWidth);
|
|
|
|
KnownOne = KnownOneLo.zext(BitWidth) |
|
|
KnownOneHi.zext(BitWidth).shl(HalfBitWidth);
|
|
break;
|
|
}
|
|
case ISD::ZERO_EXTEND: {
|
|
unsigned OperandBitWidth =
|
|
Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
|
|
APInt InMask = NewMask.trunc(OperandBitWidth);
|
|
|
|
// If none of the top bits are demanded, convert this into an any_extend.
|
|
APInt NewBits =
|
|
APInt::getHighBitsSet(BitWidth, BitWidth - OperandBitWidth) & NewMask;
|
|
if (!NewBits.intersects(NewMask))
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
|
|
Op.getValueType(),
|
|
Op.getOperand(0)));
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(0), InMask,
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
KnownZero = KnownZero.zext(BitWidth);
|
|
KnownOne = KnownOne.zext(BitWidth);
|
|
KnownZero |= NewBits;
|
|
break;
|
|
}
|
|
case ISD::SIGN_EXTEND: {
|
|
EVT InVT = Op.getOperand(0).getValueType();
|
|
unsigned InBits = InVT.getScalarType().getSizeInBits();
|
|
APInt InMask = APInt::getLowBitsSet(BitWidth, InBits);
|
|
APInt InSignBit = APInt::getBitsSet(BitWidth, InBits - 1, InBits);
|
|
APInt NewBits = ~InMask & NewMask;
|
|
|
|
// If none of the top bits are demanded, convert this into an any_extend.
|
|
if (NewBits == 0)
|
|
return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
|
|
Op.getValueType(),
|
|
Op.getOperand(0)));
|
|
|
|
// Since some of the sign extended bits are demanded, we know that the sign
|
|
// bit is demanded.
|
|
APInt InDemandedBits = InMask & NewMask;
|
|
InDemandedBits |= InSignBit;
|
|
InDemandedBits = InDemandedBits.trunc(InBits);
|
|
|
|
if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
|
|
KnownOne, TLO, Depth+1))
|
|
return true;
|
|
KnownZero = KnownZero.zext(BitWidth);
|
|
KnownOne = KnownOne.zext(BitWidth);
|
|
|
|
// If the sign bit is known zero, convert this to a zero extend.
|
|
if (KnownZero.intersects(InSignBit))
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND, dl,
|
|
Op.getValueType(),
|
|
Op.getOperand(0)));
|
|
|
|
// If the sign bit is known one, the top bits match.
|
|
if (KnownOne.intersects(InSignBit)) {
|
|
KnownOne |= NewBits;
|
|
assert((KnownZero & NewBits) == 0);
|
|
} else { // Otherwise, top bits aren't known.
|
|
assert((KnownOne & NewBits) == 0);
|
|
assert((KnownZero & NewBits) == 0);
|
|
}
|
|
break;
|
|
}
|
|
case ISD::ANY_EXTEND: {
|
|
unsigned OperandBitWidth =
|
|
Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
|
|
APInt InMask = NewMask.trunc(OperandBitWidth);
|
|
if (SimplifyDemandedBits(Op.getOperand(0), InMask,
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
KnownZero = KnownZero.zext(BitWidth);
|
|
KnownOne = KnownOne.zext(BitWidth);
|
|
break;
|
|
}
|
|
case ISD::TRUNCATE: {
|
|
// Simplify the input, using demanded bit information, and compute the known
|
|
// zero/one bits live out.
|
|
unsigned OperandBitWidth =
|
|
Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
|
|
APInt TruncMask = NewMask.zext(OperandBitWidth);
|
|
if (SimplifyDemandedBits(Op.getOperand(0), TruncMask,
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
KnownZero = KnownZero.trunc(BitWidth);
|
|
KnownOne = KnownOne.trunc(BitWidth);
|
|
|
|
// If the input is only used by this truncate, see if we can shrink it based
|
|
// on the known demanded bits.
|
|
if (Op.getOperand(0).getNode()->hasOneUse()) {
|
|
SDValue In = Op.getOperand(0);
|
|
switch (In.getOpcode()) {
|
|
default: break;
|
|
case ISD::SRL:
|
|
// Shrink SRL by a constant if none of the high bits shifted in are
|
|
// demanded.
|
|
if (TLO.LegalTypes() &&
|
|
!isTypeDesirableForOp(ISD::SRL, Op.getValueType()))
|
|
// Do not turn (vt1 truncate (vt2 srl)) into (vt1 srl) if vt1 is
|
|
// undesirable.
|
|
break;
|
|
ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1));
|
|
if (!ShAmt)
|
|
break;
|
|
SDValue Shift = In.getOperand(1);
|
|
if (TLO.LegalTypes()) {
|
|
uint64_t ShVal = ShAmt->getZExtValue();
|
|
Shift =
|
|
TLO.DAG.getConstant(ShVal, getShiftAmountTy(Op.getValueType()));
|
|
}
|
|
|
|
APInt HighBits = APInt::getHighBitsSet(OperandBitWidth,
|
|
OperandBitWidth - BitWidth);
|
|
HighBits = HighBits.lshr(ShAmt->getZExtValue()).trunc(BitWidth);
|
|
|
|
if (ShAmt->getZExtValue() < BitWidth && !(HighBits & NewMask)) {
|
|
// None of the shifted in bits are needed. Add a truncate of the
|
|
// shift input, then shift it.
|
|
SDValue NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE, dl,
|
|
Op.getValueType(),
|
|
In.getOperand(0));
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl,
|
|
Op.getValueType(),
|
|
NewTrunc,
|
|
Shift));
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
break;
|
|
}
|
|
case ISD::AssertZext: {
|
|
// AssertZext demands all of the high bits, plus any of the low bits
|
|
// demanded by its users.
|
|
EVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
|
|
APInt InMask = APInt::getLowBitsSet(BitWidth,
|
|
VT.getSizeInBits());
|
|
if (SimplifyDemandedBits(Op.getOperand(0), ~InMask | NewMask,
|
|
KnownZero, KnownOne, TLO, Depth+1))
|
|
return true;
|
|
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
|
|
|
|
KnownZero |= ~InMask & NewMask;
|
|
break;
|
|
}
|
|
case ISD::BITCAST:
|
|
// If this is an FP->Int bitcast and if the sign bit is the only
|
|
// thing demanded, turn this into a FGETSIGN.
|
|
if (!TLO.LegalOperations() &&
|
|
!Op.getValueType().isVector() &&
|
|
!Op.getOperand(0).getValueType().isVector() &&
|
|
NewMask == APInt::getSignBit(Op.getValueType().getSizeInBits()) &&
|
|
Op.getOperand(0).getValueType().isFloatingPoint()) {
|
|
bool OpVTLegal = isOperationLegalOrCustom(ISD::FGETSIGN, Op.getValueType());
|
|
bool i32Legal = isOperationLegalOrCustom(ISD::FGETSIGN, MVT::i32);
|
|
if ((OpVTLegal || i32Legal) && Op.getValueType().isSimple()) {
|
|
EVT Ty = OpVTLegal ? Op.getValueType() : MVT::i32;
|
|
// Make a FGETSIGN + SHL to move the sign bit into the appropriate
|
|
// place. We expect the SHL to be eliminated by other optimizations.
|
|
SDValue Sign = TLO.DAG.getNode(ISD::FGETSIGN, dl, Ty, Op.getOperand(0));
|
|
unsigned OpVTSizeInBits = Op.getValueType().getSizeInBits();
|
|
if (!OpVTLegal && OpVTSizeInBits > 32)
|
|
Sign = TLO.DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), Sign);
|
|
unsigned ShVal = Op.getValueType().getSizeInBits()-1;
|
|
SDValue ShAmt = TLO.DAG.getConstant(ShVal, Op.getValueType());
|
|
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, dl,
|
|
Op.getValueType(),
|
|
Sign, ShAmt));
|
|
}
|
|
}
|
|
break;
|
|
case ISD::ADD:
|
|
case ISD::MUL:
|
|
case ISD::SUB: {
|
|
// Add, Sub, and Mul don't demand any bits in positions beyond that
|
|
// of the highest bit demanded of them.
|
|
APInt LoMask = APInt::getLowBitsSet(BitWidth,
|
|
BitWidth - NewMask.countLeadingZeros());
|
|
if (SimplifyDemandedBits(Op.getOperand(0), LoMask, KnownZero2,
|
|
KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
if (SimplifyDemandedBits(Op.getOperand(1), LoMask, KnownZero2,
|
|
KnownOne2, TLO, Depth+1))
|
|
return true;
|
|
// See if the operation should be performed at a smaller bit width.
|
|
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
|
|
return true;
|
|
}
|
|
// FALL THROUGH
|
|
default:
|
|
// Just use computeKnownBits to compute output bits.
|
|
TLO.DAG.computeKnownBits(Op, KnownZero, KnownOne, Depth);
|
|
break;
|
|
}
|
|
|
|
// If we know the value of all of the demanded bits, return this as a
|
|
// constant.
|
|
if ((NewMask & (KnownZero|KnownOne)) == NewMask)
|
|
return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
|
|
|
|
return false;
|
|
}
|
|
|
|
/// computeKnownBitsForTargetNode - Determine which of the bits specified
|
|
/// in Mask are known to be either zero or one and return them in the
|
|
/// KnownZero/KnownOne bitsets.
|
|
void TargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
|
|
APInt &KnownZero,
|
|
APInt &KnownOne,
|
|
const SelectionDAG &DAG,
|
|
unsigned Depth) const {
|
|
assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
|
|
Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
|
|
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
|
|
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
|
|
"Should use MaskedValueIsZero if you don't know whether Op"
|
|
" is a target node!");
|
|
KnownZero = KnownOne = APInt(KnownOne.getBitWidth(), 0);
|
|
}
|
|
|
|
/// ComputeNumSignBitsForTargetNode - This method can be implemented by
|
|
/// targets that want to expose additional information about sign bits to the
|
|
/// DAG Combiner.
|
|
unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
|
|
const SelectionDAG &,
|
|
unsigned Depth) const {
|
|
assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
|
|
Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
|
|
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
|
|
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
|
|
"Should use ComputeNumSignBits if you don't know whether Op"
|
|
" is a target node!");
|
|
return 1;
|
|
}
|
|
|
|
/// ValueHasExactlyOneBitSet - Test if the given value is known to have exactly
|
|
/// one bit set. This differs from computeKnownBits in that it doesn't need to
|
|
/// determine which bit is set.
|
|
///
|
|
static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) {
|
|
// A left-shift of a constant one will have exactly one bit set, because
|
|
// shifting the bit off the end is undefined.
|
|
if (Val.getOpcode() == ISD::SHL)
|
|
if (ConstantSDNode *C =
|
|
dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
|
|
if (C->getAPIntValue() == 1)
|
|
return true;
|
|
|
|
// Similarly, a right-shift of a constant sign-bit will have exactly
|
|
// one bit set.
|
|
if (Val.getOpcode() == ISD::SRL)
|
|
if (ConstantSDNode *C =
|
|
dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
|
|
if (C->getAPIntValue().isSignBit())
|
|
return true;
|
|
|
|
// More could be done here, though the above checks are enough
|
|
// to handle some common cases.
|
|
|
|
// Fall back to computeKnownBits to catch other known cases.
|
|
EVT OpVT = Val.getValueType();
|
|
unsigned BitWidth = OpVT.getScalarType().getSizeInBits();
|
|
APInt KnownZero, KnownOne;
|
|
DAG.computeKnownBits(Val, KnownZero, KnownOne);
|
|
return (KnownZero.countPopulation() == BitWidth - 1) &&
|
|
(KnownOne.countPopulation() == 1);
|
|
}
|
|
|
|
bool TargetLowering::isConstTrueVal(const SDNode *N) const {
|
|
if (!N)
|
|
return false;
|
|
|
|
const ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N);
|
|
if (!CN) {
|
|
const BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N);
|
|
if (!BV)
|
|
return false;
|
|
|
|
BitVector UndefElements;
|
|
CN = BV->getConstantSplatNode(&UndefElements);
|
|
// Only interested in constant splats, and we don't try to handle undef
|
|
// elements in identifying boolean constants.
|
|
if (!CN || UndefElements.none())
|
|
return false;
|
|
}
|
|
|
|
switch (getBooleanContents(N->getValueType(0))) {
|
|
case UndefinedBooleanContent:
|
|
return CN->getAPIntValue()[0];
|
|
case ZeroOrOneBooleanContent:
|
|
return CN->isOne();
|
|
case ZeroOrNegativeOneBooleanContent:
|
|
return CN->isAllOnesValue();
|
|
}
|
|
|
|
llvm_unreachable("Invalid boolean contents");
|
|
}
|
|
|
|
bool TargetLowering::isConstFalseVal(const SDNode *N) const {
|
|
if (!N)
|
|
return false;
|
|
|
|
const ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N);
|
|
if (!CN) {
|
|
const BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N);
|
|
if (!BV)
|
|
return false;
|
|
|
|
BitVector UndefElements;
|
|
CN = BV->getConstantSplatNode(&UndefElements);
|
|
// Only interested in constant splats, and we don't try to handle undef
|
|
// elements in identifying boolean constants.
|
|
if (!CN || UndefElements.none())
|
|
return false;
|
|
}
|
|
|
|
if (getBooleanContents(N->getValueType(0)) == UndefinedBooleanContent)
|
|
return !CN->getAPIntValue()[0];
|
|
|
|
return CN->isNullValue();
|
|
}
|
|
|
|
/// SimplifySetCC - Try to simplify a setcc built with the specified operands
|
|
/// and cc. If it is unable to simplify it, return a null SDValue.
|
|
SDValue
|
|
TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
|
|
ISD::CondCode Cond, bool foldBooleans,
|
|
DAGCombinerInfo &DCI, SDLoc dl) const {
|
|
SelectionDAG &DAG = DCI.DAG;
|
|
|
|
// These setcc operations always fold.
|
|
switch (Cond) {
|
|
default: break;
|
|
case ISD::SETFALSE:
|
|
case ISD::SETFALSE2: return DAG.getConstant(0, VT);
|
|
case ISD::SETTRUE:
|
|
case ISD::SETTRUE2: {
|
|
TargetLowering::BooleanContent Cnt =
|
|
getBooleanContents(N0->getValueType(0));
|
|
return DAG.getConstant(
|
|
Cnt == TargetLowering::ZeroOrNegativeOneBooleanContent ? -1ULL : 1, VT);
|
|
}
|
|
}
|
|
|
|
// Ensure that the constant occurs on the RHS, and fold constant
|
|
// comparisons.
|
|
ISD::CondCode SwappedCC = ISD::getSetCCSwappedOperands(Cond);
|
|
if (isa<ConstantSDNode>(N0.getNode()) &&
|
|
(DCI.isBeforeLegalizeOps() ||
|
|
isCondCodeLegal(SwappedCC, N0.getSimpleValueType())))
|
|
return DAG.getSetCC(dl, VT, N1, N0, SwappedCC);
|
|
|
|
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) {
|
|
const APInt &C1 = N1C->getAPIntValue();
|
|
|
|
// If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an
|
|
// equality comparison, then we're just comparing whether X itself is
|
|
// zero.
|
|
if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) &&
|
|
N0.getOperand(0).getOpcode() == ISD::CTLZ &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant) {
|
|
const APInt &ShAmt
|
|
= cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
|
|
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
|
|
ShAmt == Log2_32(N0.getValueType().getSizeInBits())) {
|
|
if ((C1 == 0) == (Cond == ISD::SETEQ)) {
|
|
// (srl (ctlz x), 5) == 0 -> X != 0
|
|
// (srl (ctlz x), 5) != 1 -> X != 0
|
|
Cond = ISD::SETNE;
|
|
} else {
|
|
// (srl (ctlz x), 5) != 0 -> X == 0
|
|
// (srl (ctlz x), 5) == 1 -> X == 0
|
|
Cond = ISD::SETEQ;
|
|
}
|
|
SDValue Zero = DAG.getConstant(0, N0.getValueType());
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0).getOperand(0),
|
|
Zero, Cond);
|
|
}
|
|
}
|
|
|
|
SDValue CTPOP = N0;
|
|
// Look through truncs that don't change the value of a ctpop.
|
|
if (N0.hasOneUse() && N0.getOpcode() == ISD::TRUNCATE)
|
|
CTPOP = N0.getOperand(0);
|
|
|
|
if (CTPOP.hasOneUse() && CTPOP.getOpcode() == ISD::CTPOP &&
|
|
(N0 == CTPOP || N0.getValueType().getSizeInBits() >
|
|
Log2_32_Ceil(CTPOP.getValueType().getSizeInBits()))) {
|
|
EVT CTVT = CTPOP.getValueType();
|
|
SDValue CTOp = CTPOP.getOperand(0);
|
|
|
|
// (ctpop x) u< 2 -> (x & x-1) == 0
|
|
// (ctpop x) u> 1 -> (x & x-1) != 0
|
|
if ((Cond == ISD::SETULT && C1 == 2) || (Cond == ISD::SETUGT && C1 == 1)){
|
|
SDValue Sub = DAG.getNode(ISD::SUB, dl, CTVT, CTOp,
|
|
DAG.getConstant(1, CTVT));
|
|
SDValue And = DAG.getNode(ISD::AND, dl, CTVT, CTOp, Sub);
|
|
ISD::CondCode CC = Cond == ISD::SETULT ? ISD::SETEQ : ISD::SETNE;
|
|
return DAG.getSetCC(dl, VT, And, DAG.getConstant(0, CTVT), CC);
|
|
}
|
|
|
|
// TODO: (ctpop x) == 1 -> x && (x & x-1) == 0 iff ctpop is illegal.
|
|
}
|
|
|
|
// (zext x) == C --> x == (trunc C)
|
|
// (sext x) == C --> x == (trunc C)
|
|
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
|
|
DCI.isBeforeLegalize() && N0->hasOneUse()) {
|
|
unsigned MinBits = N0.getValueSizeInBits();
|
|
SDValue PreExt;
|
|
bool Signed = false;
|
|
if (N0->getOpcode() == ISD::ZERO_EXTEND) {
|
|
// ZExt
|
|
MinBits = N0->getOperand(0).getValueSizeInBits();
|
|
PreExt = N0->getOperand(0);
|
|
} else if (N0->getOpcode() == ISD::AND) {
|
|
// DAGCombine turns costly ZExts into ANDs
|
|
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0->getOperand(1)))
|
|
if ((C->getAPIntValue()+1).isPowerOf2()) {
|
|
MinBits = C->getAPIntValue().countTrailingOnes();
|
|
PreExt = N0->getOperand(0);
|
|
}
|
|
} else if (N0->getOpcode() == ISD::SIGN_EXTEND) {
|
|
// SExt
|
|
MinBits = N0->getOperand(0).getValueSizeInBits();
|
|
PreExt = N0->getOperand(0);
|
|
Signed = true;
|
|
} else if (LoadSDNode *LN0 = dyn_cast<LoadSDNode>(N0)) {
|
|
// ZEXTLOAD / SEXTLOAD
|
|
if (LN0->getExtensionType() == ISD::ZEXTLOAD) {
|
|
MinBits = LN0->getMemoryVT().getSizeInBits();
|
|
PreExt = N0;
|
|
} else if (LN0->getExtensionType() == ISD::SEXTLOAD) {
|
|
Signed = true;
|
|
MinBits = LN0->getMemoryVT().getSizeInBits();
|
|
PreExt = N0;
|
|
}
|
|
}
|
|
|
|
// Figure out how many bits we need to preserve this constant.
|
|
unsigned ReqdBits = Signed ?
|
|
C1.getBitWidth() - C1.getNumSignBits() + 1 :
|
|
C1.getActiveBits();
|
|
|
|
// Make sure we're not losing bits from the constant.
|
|
if (MinBits > 0 &&
|
|
MinBits < C1.getBitWidth() &&
|
|
MinBits >= ReqdBits) {
|
|
EVT MinVT = EVT::getIntegerVT(*DAG.getContext(), MinBits);
|
|
if (isTypeDesirableForOp(ISD::SETCC, MinVT)) {
|
|
// Will get folded away.
|
|
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MinVT, PreExt);
|
|
SDValue C = DAG.getConstant(C1.trunc(MinBits), MinVT);
|
|
return DAG.getSetCC(dl, VT, Trunc, C, Cond);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the LHS is '(and load, const)', the RHS is 0,
|
|
// the test is for equality or unsigned, and all 1 bits of the const are
|
|
// in the same partial word, see if we can shorten the load.
|
|
if (DCI.isBeforeLegalize() &&
|
|
!ISD::isSignedIntSetCC(Cond) &&
|
|
N0.getOpcode() == ISD::AND && C1 == 0 &&
|
|
N0.getNode()->hasOneUse() &&
|
|
isa<LoadSDNode>(N0.getOperand(0)) &&
|
|
N0.getOperand(0).getNode()->hasOneUse() &&
|
|
isa<ConstantSDNode>(N0.getOperand(1))) {
|
|
LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0));
|
|
APInt bestMask;
|
|
unsigned bestWidth = 0, bestOffset = 0;
|
|
if (!Lod->isVolatile() && Lod->isUnindexed()) {
|
|
unsigned origWidth = N0.getValueType().getSizeInBits();
|
|
unsigned maskWidth = origWidth;
|
|
// We can narrow (e.g.) 16-bit extending loads on 32-bit target to
|
|
// 8 bits, but have to be careful...
|
|
if (Lod->getExtensionType() != ISD::NON_EXTLOAD)
|
|
origWidth = Lod->getMemoryVT().getSizeInBits();
|
|
const APInt &Mask =
|
|
cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
|
|
for (unsigned width = origWidth / 2; width>=8; width /= 2) {
|
|
APInt newMask = APInt::getLowBitsSet(maskWidth, width);
|
|
for (unsigned offset=0; offset<origWidth/width; offset++) {
|
|
if ((newMask & Mask) == Mask) {
|
|
if (!getDataLayout()->isLittleEndian())
|
|
bestOffset = (origWidth/width - offset - 1) * (width/8);
|
|
else
|
|
bestOffset = (uint64_t)offset * (width/8);
|
|
bestMask = Mask.lshr(offset * (width/8) * 8);
|
|
bestWidth = width;
|
|
break;
|
|
}
|
|
newMask = newMask << width;
|
|
}
|
|
}
|
|
}
|
|
if (bestWidth) {
|
|
EVT newVT = EVT::getIntegerVT(*DAG.getContext(), bestWidth);
|
|
if (newVT.isRound()) {
|
|
EVT PtrType = Lod->getOperand(1).getValueType();
|
|
SDValue Ptr = Lod->getBasePtr();
|
|
if (bestOffset != 0)
|
|
Ptr = DAG.getNode(ISD::ADD, dl, PtrType, Lod->getBasePtr(),
|
|
DAG.getConstant(bestOffset, PtrType));
|
|
unsigned NewAlign = MinAlign(Lod->getAlignment(), bestOffset);
|
|
SDValue NewLoad = DAG.getLoad(newVT, dl, Lod->getChain(), Ptr,
|
|
Lod->getPointerInfo().getWithOffset(bestOffset),
|
|
false, false, false, NewAlign);
|
|
return DAG.getSetCC(dl, VT,
|
|
DAG.getNode(ISD::AND, dl, newVT, NewLoad,
|
|
DAG.getConstant(bestMask.trunc(bestWidth),
|
|
newVT)),
|
|
DAG.getConstant(0LL, newVT), Cond);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the LHS is a ZERO_EXTEND, perform the comparison on the input.
|
|
if (N0.getOpcode() == ISD::ZERO_EXTEND) {
|
|
unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits();
|
|
|
|
// If the comparison constant has bits in the upper part, the
|
|
// zero-extended value could never match.
|
|
if (C1.intersects(APInt::getHighBitsSet(C1.getBitWidth(),
|
|
C1.getBitWidth() - InSize))) {
|
|
switch (Cond) {
|
|
case ISD::SETUGT:
|
|
case ISD::SETUGE:
|
|
case ISD::SETEQ: return DAG.getConstant(0, VT);
|
|
case ISD::SETULT:
|
|
case ISD::SETULE:
|
|
case ISD::SETNE: return DAG.getConstant(1, VT);
|
|
case ISD::SETGT:
|
|
case ISD::SETGE:
|
|
// True if the sign bit of C1 is set.
|
|
return DAG.getConstant(C1.isNegative(), VT);
|
|
case ISD::SETLT:
|
|
case ISD::SETLE:
|
|
// True if the sign bit of C1 isn't set.
|
|
return DAG.getConstant(C1.isNonNegative(), VT);
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Otherwise, we can perform the comparison with the low bits.
|
|
switch (Cond) {
|
|
case ISD::SETEQ:
|
|
case ISD::SETNE:
|
|
case ISD::SETUGT:
|
|
case ISD::SETUGE:
|
|
case ISD::SETULT:
|
|
case ISD::SETULE: {
|
|
EVT newVT = N0.getOperand(0).getValueType();
|
|
if (DCI.isBeforeLegalizeOps() ||
|
|
(isOperationLegal(ISD::SETCC, newVT) &&
|
|
getCondCodeAction(Cond, newVT.getSimpleVT()) == Legal)) {
|
|
EVT NewSetCCVT = getSetCCResultType(*DAG.getContext(), newVT);
|
|
SDValue NewConst = DAG.getConstant(C1.trunc(InSize), newVT);
|
|
|
|
SDValue NewSetCC = DAG.getSetCC(dl, NewSetCCVT, N0.getOperand(0),
|
|
NewConst, Cond);
|
|
return DAG.getBoolExtOrTrunc(NewSetCC, dl, VT, N0.getValueType());
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
break; // todo, be more careful with signed comparisons
|
|
}
|
|
} else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
|
|
(Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
|
|
EVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
|
|
unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits();
|
|
EVT ExtDstTy = N0.getValueType();
|
|
unsigned ExtDstTyBits = ExtDstTy.getSizeInBits();
|
|
|
|
// If the constant doesn't fit into the number of bits for the source of
|
|
// the sign extension, it is impossible for both sides to be equal.
|
|
if (C1.getMinSignedBits() > ExtSrcTyBits)
|
|
return DAG.getConstant(Cond == ISD::SETNE, VT);
|
|
|
|
SDValue ZextOp;
|
|
EVT Op0Ty = N0.getOperand(0).getValueType();
|
|
if (Op0Ty == ExtSrcTy) {
|
|
ZextOp = N0.getOperand(0);
|
|
} else {
|
|
APInt Imm = APInt::getLowBitsSet(ExtDstTyBits, ExtSrcTyBits);
|
|
ZextOp = DAG.getNode(ISD::AND, dl, Op0Ty, N0.getOperand(0),
|
|
DAG.getConstant(Imm, Op0Ty));
|
|
}
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(ZextOp.getNode());
|
|
// Otherwise, make this a use of a zext.
|
|
return DAG.getSetCC(dl, VT, ZextOp,
|
|
DAG.getConstant(C1 & APInt::getLowBitsSet(
|
|
ExtDstTyBits,
|
|
ExtSrcTyBits),
|
|
ExtDstTy),
|
|
Cond);
|
|
} else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) &&
|
|
(Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
|
|
// SETCC (SETCC), [0|1], [EQ|NE] -> SETCC
|
|
if (N0.getOpcode() == ISD::SETCC &&
|
|
isTypeLegal(VT) && VT.bitsLE(N0.getValueType())) {
|
|
bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getAPIntValue() != 1);
|
|
if (TrueWhenTrue)
|
|
return DAG.getNode(ISD::TRUNCATE, dl, VT, N0);
|
|
// Invert the condition.
|
|
ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
|
|
CC = ISD::getSetCCInverse(CC,
|
|
N0.getOperand(0).getValueType().isInteger());
|
|
if (DCI.isBeforeLegalizeOps() ||
|
|
isCondCodeLegal(CC, N0.getOperand(0).getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
|
|
}
|
|
|
|
if ((N0.getOpcode() == ISD::XOR ||
|
|
(N0.getOpcode() == ISD::AND &&
|
|
N0.getOperand(0).getOpcode() == ISD::XOR &&
|
|
N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
|
|
isa<ConstantSDNode>(N0.getOperand(1)) &&
|
|
cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue() == 1) {
|
|
// If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We
|
|
// can only do this if the top bits are known zero.
|
|
unsigned BitWidth = N0.getValueSizeInBits();
|
|
if (DAG.MaskedValueIsZero(N0,
|
|
APInt::getHighBitsSet(BitWidth,
|
|
BitWidth-1))) {
|
|
// Okay, get the un-inverted input value.
|
|
SDValue Val;
|
|
if (N0.getOpcode() == ISD::XOR)
|
|
Val = N0.getOperand(0);
|
|
else {
|
|
assert(N0.getOpcode() == ISD::AND &&
|
|
N0.getOperand(0).getOpcode() == ISD::XOR);
|
|
// ((X^1)&1)^1 -> X & 1
|
|
Val = DAG.getNode(ISD::AND, dl, N0.getValueType(),
|
|
N0.getOperand(0).getOperand(0),
|
|
N0.getOperand(1));
|
|
}
|
|
|
|
return DAG.getSetCC(dl, VT, Val, N1,
|
|
Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
|
|
}
|
|
} else if (N1C->getAPIntValue() == 1 &&
|
|
(VT == MVT::i1 ||
|
|
getBooleanContents(N0->getValueType(0)) ==
|
|
ZeroOrOneBooleanContent)) {
|
|
SDValue Op0 = N0;
|
|
if (Op0.getOpcode() == ISD::TRUNCATE)
|
|
Op0 = Op0.getOperand(0);
|
|
|
|
if ((Op0.getOpcode() == ISD::XOR) &&
|
|
Op0.getOperand(0).getOpcode() == ISD::SETCC &&
|
|
Op0.getOperand(1).getOpcode() == ISD::SETCC) {
|
|
// (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc)
|
|
Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
|
|
return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
|
|
Cond);
|
|
}
|
|
if (Op0.getOpcode() == ISD::AND &&
|
|
isa<ConstantSDNode>(Op0.getOperand(1)) &&
|
|
cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
|
|
// If this is (X&1) == / != 1, normalize it to (X&1) != / == 0.
|
|
if (Op0.getValueType().bitsGT(VT))
|
|
Op0 = DAG.getNode(ISD::AND, dl, VT,
|
|
DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)),
|
|
DAG.getConstant(1, VT));
|
|
else if (Op0.getValueType().bitsLT(VT))
|
|
Op0 = DAG.getNode(ISD::AND, dl, VT,
|
|
DAG.getNode(ISD::ANY_EXTEND, dl, VT, Op0.getOperand(0)),
|
|
DAG.getConstant(1, VT));
|
|
|
|
return DAG.getSetCC(dl, VT, Op0,
|
|
DAG.getConstant(0, Op0.getValueType()),
|
|
Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
|
|
}
|
|
if (Op0.getOpcode() == ISD::AssertZext &&
|
|
cast<VTSDNode>(Op0.getOperand(1))->getVT() == MVT::i1)
|
|
return DAG.getSetCC(dl, VT, Op0,
|
|
DAG.getConstant(0, Op0.getValueType()),
|
|
Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
|
|
}
|
|
}
|
|
|
|
APInt MinVal, MaxVal;
|
|
unsigned OperandBitSize = N1C->getValueType(0).getSizeInBits();
|
|
if (ISD::isSignedIntSetCC(Cond)) {
|
|
MinVal = APInt::getSignedMinValue(OperandBitSize);
|
|
MaxVal = APInt::getSignedMaxValue(OperandBitSize);
|
|
} else {
|
|
MinVal = APInt::getMinValue(OperandBitSize);
|
|
MaxVal = APInt::getMaxValue(OperandBitSize);
|
|
}
|
|
|
|
// Canonicalize GE/LE comparisons to use GT/LT comparisons.
|
|
if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
|
|
if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
|
|
// X >= C0 --> X > (C0 - 1)
|
|
APInt C = C1 - 1;
|
|
ISD::CondCode NewCC = (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT;
|
|
if ((DCI.isBeforeLegalizeOps() ||
|
|
isCondCodeLegal(NewCC, VT.getSimpleVT())) &&
|
|
(!N1C->isOpaque() || (N1C->isOpaque() && C.getBitWidth() <= 64 &&
|
|
isLegalICmpImmediate(C.getSExtValue())))) {
|
|
return DAG.getSetCC(dl, VT, N0,
|
|
DAG.getConstant(C, N1.getValueType()),
|
|
NewCC);
|
|
}
|
|
}
|
|
|
|
if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
|
|
if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
|
|
// X <= C0 --> X < (C0 + 1)
|
|
APInt C = C1 + 1;
|
|
ISD::CondCode NewCC = (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT;
|
|
if ((DCI.isBeforeLegalizeOps() ||
|
|
isCondCodeLegal(NewCC, VT.getSimpleVT())) &&
|
|
(!N1C->isOpaque() || (N1C->isOpaque() && C.getBitWidth() <= 64 &&
|
|
isLegalICmpImmediate(C.getSExtValue())))) {
|
|
return DAG.getSetCC(dl, VT, N0,
|
|
DAG.getConstant(C, N1.getValueType()),
|
|
NewCC);
|
|
}
|
|
}
|
|
|
|
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
|
|
return DAG.getConstant(0, VT); // X < MIN --> false
|
|
if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal)
|
|
return DAG.getConstant(1, VT); // X >= MIN --> true
|
|
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal)
|
|
return DAG.getConstant(0, VT); // X > MAX --> false
|
|
if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal)
|
|
return DAG.getConstant(1, VT); // X <= MAX --> true
|
|
|
|
// Canonicalize setgt X, Min --> setne X, Min
|
|
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
|
|
// Canonicalize setlt X, Max --> setne X, Max
|
|
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
|
|
|
|
// If we have setult X, 1, turn it into seteq X, 0
|
|
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
|
|
return DAG.getSetCC(dl, VT, N0,
|
|
DAG.getConstant(MinVal, N0.getValueType()),
|
|
ISD::SETEQ);
|
|
// If we have setugt X, Max-1, turn it into seteq X, Max
|
|
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
|
|
return DAG.getSetCC(dl, VT, N0,
|
|
DAG.getConstant(MaxVal, N0.getValueType()),
|
|
ISD::SETEQ);
|
|
|
|
// If we have "setcc X, C0", check to see if we can shrink the immediate
|
|
// by changing cc.
|
|
|
|
// SETUGT X, SINTMAX -> SETLT X, 0
|
|
if (Cond == ISD::SETUGT &&
|
|
C1 == APInt::getSignedMaxValue(OperandBitSize))
|
|
return DAG.getSetCC(dl, VT, N0,
|
|
DAG.getConstant(0, N1.getValueType()),
|
|
ISD::SETLT);
|
|
|
|
// SETULT X, SINTMIN -> SETGT X, -1
|
|
if (Cond == ISD::SETULT &&
|
|
C1 == APInt::getSignedMinValue(OperandBitSize)) {
|
|
SDValue ConstMinusOne =
|
|
DAG.getConstant(APInt::getAllOnesValue(OperandBitSize),
|
|
N1.getValueType());
|
|
return DAG.getSetCC(dl, VT, N0, ConstMinusOne, ISD::SETGT);
|
|
}
|
|
|
|
// Fold bit comparisons when we can.
|
|
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
|
|
(VT == N0.getValueType() ||
|
|
(isTypeLegal(VT) && VT.bitsLE(N0.getValueType()))) &&
|
|
N0.getOpcode() == ISD::AND)
|
|
if (ConstantSDNode *AndRHS =
|
|
dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
|
|
EVT ShiftTy = DCI.isBeforeLegalize() ?
|
|
getPointerTy() : getShiftAmountTy(N0.getValueType());
|
|
if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
|
|
// Perform the xform if the AND RHS is a single bit.
|
|
if (AndRHS->getAPIntValue().isPowerOf2()) {
|
|
return DAG.getNode(ISD::TRUNCATE, dl, VT,
|
|
DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0,
|
|
DAG.getConstant(AndRHS->getAPIntValue().logBase2(), ShiftTy)));
|
|
}
|
|
} else if (Cond == ISD::SETEQ && C1 == AndRHS->getAPIntValue()) {
|
|
// (X & 8) == 8 --> (X & 8) >> 3
|
|
// Perform the xform if C1 is a single bit.
|
|
if (C1.isPowerOf2()) {
|
|
return DAG.getNode(ISD::TRUNCATE, dl, VT,
|
|
DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0,
|
|
DAG.getConstant(C1.logBase2(), ShiftTy)));
|
|
}
|
|
}
|
|
}
|
|
|
|
if (C1.getMinSignedBits() <= 64 &&
|
|
!isLegalICmpImmediate(C1.getSExtValue())) {
|
|
// (X & -256) == 256 -> (X >> 8) == 1
|
|
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
|
|
N0.getOpcode() == ISD::AND && N0.hasOneUse()) {
|
|
if (ConstantSDNode *AndRHS =
|
|
dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
|
|
const APInt &AndRHSC = AndRHS->getAPIntValue();
|
|
if ((-AndRHSC).isPowerOf2() && (AndRHSC & C1) == C1) {
|
|
unsigned ShiftBits = AndRHSC.countTrailingZeros();
|
|
EVT ShiftTy = DCI.isBeforeLegalize() ?
|
|
getPointerTy() : getShiftAmountTy(N0.getValueType());
|
|
EVT CmpTy = N0.getValueType();
|
|
SDValue Shift = DAG.getNode(ISD::SRL, dl, CmpTy, N0.getOperand(0),
|
|
DAG.getConstant(ShiftBits, ShiftTy));
|
|
SDValue CmpRHS = DAG.getConstant(C1.lshr(ShiftBits), CmpTy);
|
|
return DAG.getSetCC(dl, VT, Shift, CmpRHS, Cond);
|
|
}
|
|
}
|
|
} else if (Cond == ISD::SETULT || Cond == ISD::SETUGE ||
|
|
Cond == ISD::SETULE || Cond == ISD::SETUGT) {
|
|
bool AdjOne = (Cond == ISD::SETULE || Cond == ISD::SETUGT);
|
|
// X < 0x100000000 -> (X >> 32) < 1
|
|
// X >= 0x100000000 -> (X >> 32) >= 1
|
|
// X <= 0x0ffffffff -> (X >> 32) < 1
|
|
// X > 0x0ffffffff -> (X >> 32) >= 1
|
|
unsigned ShiftBits;
|
|
APInt NewC = C1;
|
|
ISD::CondCode NewCond = Cond;
|
|
if (AdjOne) {
|
|
ShiftBits = C1.countTrailingOnes();
|
|
NewC = NewC + 1;
|
|
NewCond = (Cond == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
|
|
} else {
|
|
ShiftBits = C1.countTrailingZeros();
|
|
}
|
|
NewC = NewC.lshr(ShiftBits);
|
|
if (ShiftBits && isLegalICmpImmediate(NewC.getSExtValue())) {
|
|
EVT ShiftTy = DCI.isBeforeLegalize() ?
|
|
getPointerTy() : getShiftAmountTy(N0.getValueType());
|
|
EVT CmpTy = N0.getValueType();
|
|
SDValue Shift = DAG.getNode(ISD::SRL, dl, CmpTy, N0,
|
|
DAG.getConstant(ShiftBits, ShiftTy));
|
|
SDValue CmpRHS = DAG.getConstant(NewC, CmpTy);
|
|
return DAG.getSetCC(dl, VT, Shift, CmpRHS, NewCond);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (isa<ConstantFPSDNode>(N0.getNode())) {
|
|
// Constant fold or commute setcc.
|
|
SDValue O = DAG.FoldSetCC(VT, N0, N1, Cond, dl);
|
|
if (O.getNode()) return O;
|
|
} else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.getNode())) {
|
|
// If the RHS of an FP comparison is a constant, simplify it away in
|
|
// some cases.
|
|
if (CFP->getValueAPF().isNaN()) {
|
|
// If an operand is known to be a nan, we can fold it.
|
|
switch (ISD::getUnorderedFlavor(Cond)) {
|
|
default: llvm_unreachable("Unknown flavor!");
|
|
case 0: // Known false.
|
|
return DAG.getConstant(0, VT);
|
|
case 1: // Known true.
|
|
return DAG.getConstant(1, VT);
|
|
case 2: // Undefined.
|
|
return DAG.getUNDEF(VT);
|
|
}
|
|
}
|
|
|
|
// Otherwise, we know the RHS is not a NaN. Simplify the node to drop the
|
|
// constant if knowing that the operand is non-nan is enough. We prefer to
|
|
// have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to
|
|
// materialize 0.0.
|
|
if (Cond == ISD::SETO || Cond == ISD::SETUO)
|
|
return DAG.getSetCC(dl, VT, N0, N0, Cond);
|
|
|
|
// If the condition is not legal, see if we can find an equivalent one
|
|
// which is legal.
|
|
if (!isCondCodeLegal(Cond, N0.getSimpleValueType())) {
|
|
// If the comparison was an awkward floating-point == or != and one of
|
|
// the comparison operands is infinity or negative infinity, convert the
|
|
// condition to a less-awkward <= or >=.
|
|
if (CFP->getValueAPF().isInfinity()) {
|
|
if (CFP->getValueAPF().isNegative()) {
|
|
if (Cond == ISD::SETOEQ &&
|
|
isCondCodeLegal(ISD::SETOLE, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLE);
|
|
if (Cond == ISD::SETUEQ &&
|
|
isCondCodeLegal(ISD::SETOLE, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULE);
|
|
if (Cond == ISD::SETUNE &&
|
|
isCondCodeLegal(ISD::SETUGT, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGT);
|
|
if (Cond == ISD::SETONE &&
|
|
isCondCodeLegal(ISD::SETUGT, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGT);
|
|
} else {
|
|
if (Cond == ISD::SETOEQ &&
|
|
isCondCodeLegal(ISD::SETOGE, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGE);
|
|
if (Cond == ISD::SETUEQ &&
|
|
isCondCodeLegal(ISD::SETOGE, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGE);
|
|
if (Cond == ISD::SETUNE &&
|
|
isCondCodeLegal(ISD::SETULT, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULT);
|
|
if (Cond == ISD::SETONE &&
|
|
isCondCodeLegal(ISD::SETULT, N0.getSimpleValueType()))
|
|
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLT);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (N0 == N1) {
|
|
// The sext(setcc()) => setcc() optimization relies on the appropriate
|
|
// constant being emitted.
|
|
uint64_t EqVal = 0;
|
|
switch (getBooleanContents(N0.getValueType())) {
|
|
case UndefinedBooleanContent:
|
|
case ZeroOrOneBooleanContent:
|
|
EqVal = ISD::isTrueWhenEqual(Cond);
|
|
break;
|
|
case ZeroOrNegativeOneBooleanContent:
|
|
EqVal = ISD::isTrueWhenEqual(Cond) ? -1 : 0;
|
|
break;
|
|
}
|
|
|
|
// We can always fold X == X for integer setcc's.
|
|
if (N0.getValueType().isInteger()) {
|
|
return DAG.getConstant(EqVal, VT);
|
|
}
|
|
unsigned UOF = ISD::getUnorderedFlavor(Cond);
|
|
if (UOF == 2) // FP operators that are undefined on NaNs.
|
|
return DAG.getConstant(EqVal, VT);
|
|
if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
|
|
return DAG.getConstant(EqVal, VT);
|
|
// Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
|
|
// if it is not already.
|
|
ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
|
|
if (NewCond != Cond && (DCI.isBeforeLegalizeOps() ||
|
|
getCondCodeAction(NewCond, N0.getSimpleValueType()) == Legal))
|
|
return DAG.getSetCC(dl, VT, N0, N1, NewCond);
|
|
}
|
|
|
|
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
|
|
N0.getValueType().isInteger()) {
|
|
if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
|
|
N0.getOpcode() == ISD::XOR) {
|
|
// Simplify (X+Y) == (X+Z) --> Y == Z
|
|
if (N0.getOpcode() == N1.getOpcode()) {
|
|
if (N0.getOperand(0) == N1.getOperand(0))
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(1), Cond);
|
|
if (N0.getOperand(1) == N1.getOperand(1))
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(0), Cond);
|
|
if (DAG.isCommutativeBinOp(N0.getOpcode())) {
|
|
// If X op Y == Y op X, try other combinations.
|
|
if (N0.getOperand(0) == N1.getOperand(1))
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(0),
|
|
Cond);
|
|
if (N0.getOperand(1) == N1.getOperand(0))
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(1),
|
|
Cond);
|
|
}
|
|
}
|
|
|
|
// If RHS is a legal immediate value for a compare instruction, we need
|
|
// to be careful about increasing register pressure needlessly.
|
|
bool LegalRHSImm = false;
|
|
|
|
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
|
|
if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
|
|
// Turn (X+C1) == C2 --> X == C2-C1
|
|
if (N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse()) {
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0),
|
|
DAG.getConstant(RHSC->getAPIntValue()-
|
|
LHSR->getAPIntValue(),
|
|
N0.getValueType()), Cond);
|
|
}
|
|
|
|
// Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
|
|
if (N0.getOpcode() == ISD::XOR)
|
|
// If we know that all of the inverted bits are zero, don't bother
|
|
// performing the inversion.
|
|
if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getAPIntValue()))
|
|
return
|
|
DAG.getSetCC(dl, VT, N0.getOperand(0),
|
|
DAG.getConstant(LHSR->getAPIntValue() ^
|
|
RHSC->getAPIntValue(),
|
|
N0.getValueType()),
|
|
Cond);
|
|
}
|
|
|
|
// Turn (C1-X) == C2 --> X == C1-C2
|
|
if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
|
|
if (N0.getOpcode() == ISD::SUB && N0.getNode()->hasOneUse()) {
|
|
return
|
|
DAG.getSetCC(dl, VT, N0.getOperand(1),
|
|
DAG.getConstant(SUBC->getAPIntValue() -
|
|
RHSC->getAPIntValue(),
|
|
N0.getValueType()),
|
|
Cond);
|
|
}
|
|
}
|
|
|
|
// Could RHSC fold directly into a compare?
|
|
if (RHSC->getValueType(0).getSizeInBits() <= 64)
|
|
LegalRHSImm = isLegalICmpImmediate(RHSC->getSExtValue());
|
|
}
|
|
|
|
// Simplify (X+Z) == X --> Z == 0
|
|
// Don't do this if X is an immediate that can fold into a cmp
|
|
// instruction and X+Z has other uses. It could be an induction variable
|
|
// chain, and the transform would increase register pressure.
|
|
if (!LegalRHSImm || N0.getNode()->hasOneUse()) {
|
|
if (N0.getOperand(0) == N1)
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(1),
|
|
DAG.getConstant(0, N0.getValueType()), Cond);
|
|
if (N0.getOperand(1) == N1) {
|
|
if (DAG.isCommutativeBinOp(N0.getOpcode()))
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0),
|
|
DAG.getConstant(0, N0.getValueType()), Cond);
|
|
if (N0.getNode()->hasOneUse()) {
|
|
assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
|
|
// (Z-X) == X --> Z == X<<1
|
|
SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N1,
|
|
DAG.getConstant(1, getShiftAmountTy(N1.getValueType())));
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(SH.getNode());
|
|
return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
|
|
N1.getOpcode() == ISD::XOR) {
|
|
// Simplify X == (X+Z) --> Z == 0
|
|
if (N1.getOperand(0) == N0)
|
|
return DAG.getSetCC(dl, VT, N1.getOperand(1),
|
|
DAG.getConstant(0, N1.getValueType()), Cond);
|
|
if (N1.getOperand(1) == N0) {
|
|
if (DAG.isCommutativeBinOp(N1.getOpcode()))
|
|
return DAG.getSetCC(dl, VT, N1.getOperand(0),
|
|
DAG.getConstant(0, N1.getValueType()), Cond);
|
|
if (N1.getNode()->hasOneUse()) {
|
|
assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
|
|
// X == (Z-X) --> X<<1 == Z
|
|
SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N0,
|
|
DAG.getConstant(1, getShiftAmountTy(N0.getValueType())));
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(SH.getNode());
|
|
return DAG.getSetCC(dl, VT, SH, N1.getOperand(0), Cond);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Simplify x&y == y to x&y != 0 if y has exactly one bit set.
|
|
// Note that where y is variable and is known to have at most
|
|
// one bit set (for example, if it is z&1) we cannot do this;
|
|
// the expressions are not equivalent when y==0.
|
|
if (N0.getOpcode() == ISD::AND)
|
|
if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) {
|
|
if (ValueHasExactlyOneBitSet(N1, DAG)) {
|
|
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
|
|
if (DCI.isBeforeLegalizeOps() ||
|
|
isCondCodeLegal(Cond, N0.getSimpleValueType())) {
|
|
SDValue Zero = DAG.getConstant(0, N1.getValueType());
|
|
return DAG.getSetCC(dl, VT, N0, Zero, Cond);
|
|
}
|
|
}
|
|
}
|
|
if (N1.getOpcode() == ISD::AND)
|
|
if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) {
|
|
if (ValueHasExactlyOneBitSet(N0, DAG)) {
|
|
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
|
|
if (DCI.isBeforeLegalizeOps() ||
|
|
isCondCodeLegal(Cond, N1.getSimpleValueType())) {
|
|
SDValue Zero = DAG.getConstant(0, N0.getValueType());
|
|
return DAG.getSetCC(dl, VT, N1, Zero, Cond);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Fold away ALL boolean setcc's.
|
|
SDValue Temp;
|
|
if (N0.getValueType() == MVT::i1 && foldBooleans) {
|
|
switch (Cond) {
|
|
default: llvm_unreachable("Unknown integer setcc!");
|
|
case ISD::SETEQ: // X == Y -> ~(X^Y)
|
|
Temp = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
|
|
N0 = DAG.getNOT(dl, Temp, MVT::i1);
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(Temp.getNode());
|
|
break;
|
|
case ISD::SETNE: // X != Y --> (X^Y)
|
|
N0 = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
|
|
break;
|
|
case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> ~X & Y
|
|
case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> ~X & Y
|
|
Temp = DAG.getNOT(dl, N0, MVT::i1);
|
|
N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N1, Temp);
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(Temp.getNode());
|
|
break;
|
|
case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> ~Y & X
|
|
case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> ~Y & X
|
|
Temp = DAG.getNOT(dl, N1, MVT::i1);
|
|
N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N0, Temp);
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(Temp.getNode());
|
|
break;
|
|
case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> ~X | Y
|
|
case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> ~X | Y
|
|
Temp = DAG.getNOT(dl, N0, MVT::i1);
|
|
N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N1, Temp);
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(Temp.getNode());
|
|
break;
|
|
case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> ~Y | X
|
|
case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> ~Y | X
|
|
Temp = DAG.getNOT(dl, N1, MVT::i1);
|
|
N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N0, Temp);
|
|
break;
|
|
}
|
|
if (VT != MVT::i1) {
|
|
if (!DCI.isCalledByLegalizer())
|
|
DCI.AddToWorklist(N0.getNode());
|
|
// FIXME: If running after legalize, we probably can't do this.
|
|
N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0);
|
|
}
|
|
return N0;
|
|
}
|
|
|
|
// Could not fold it.
|
|
return SDValue();
|
|
}
|
|
|
|
/// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
|
|
/// node is a GlobalAddress + offset.
|
|
bool TargetLowering::isGAPlusOffset(SDNode *N, const GlobalValue *&GA,
|
|
int64_t &Offset) const {
|
|
if (isa<GlobalAddressSDNode>(N)) {
|
|
GlobalAddressSDNode *GASD = cast<GlobalAddressSDNode>(N);
|
|
GA = GASD->getGlobal();
|
|
Offset += GASD->getOffset();
|
|
return true;
|
|
}
|
|
|
|
if (N->getOpcode() == ISD::ADD) {
|
|
SDValue N1 = N->getOperand(0);
|
|
SDValue N2 = N->getOperand(1);
|
|
if (isGAPlusOffset(N1.getNode(), GA, Offset)) {
|
|
ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2);
|
|
if (V) {
|
|
Offset += V->getSExtValue();
|
|
return true;
|
|
}
|
|
} else if (isGAPlusOffset(N2.getNode(), GA, Offset)) {
|
|
ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1);
|
|
if (V) {
|
|
Offset += V->getSExtValue();
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
SDValue TargetLowering::
|
|
PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
|
|
// Default implementation: no optimization.
|
|
return SDValue();
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Inline Assembler Implementation Methods
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
TargetLowering::ConstraintType
|
|
TargetLowering::getConstraintType(const std::string &Constraint) const {
|
|
unsigned S = Constraint.size();
|
|
|
|
if (S == 1) {
|
|
switch (Constraint[0]) {
|
|
default: break;
|
|
case 'r': return C_RegisterClass;
|
|
case 'm': // memory
|
|
case 'o': // offsetable
|
|
case 'V': // not offsetable
|
|
return C_Memory;
|
|
case 'i': // Simple Integer or Relocatable Constant
|
|
case 'n': // Simple Integer
|
|
case 'E': // Floating Point Constant
|
|
case 'F': // Floating Point Constant
|
|
case 's': // Relocatable Constant
|
|
case 'p': // Address.
|
|
case 'X': // Allow ANY value.
|
|
case 'I': // Target registers.
|
|
case 'J':
|
|
case 'K':
|
|
case 'L':
|
|
case 'M':
|
|
case 'N':
|
|
case 'O':
|
|
case 'P':
|
|
case '<':
|
|
case '>':
|
|
return C_Other;
|
|
}
|
|
}
|
|
|
|
if (S > 1 && Constraint[0] == '{' && Constraint[S-1] == '}') {
|
|
if (S == 8 && !Constraint.compare(1, 6, "memory", 6)) // "{memory}"
|
|
return C_Memory;
|
|
return C_Register;
|
|
}
|
|
return C_Unknown;
|
|
}
|
|
|
|
/// LowerXConstraint - try to replace an X constraint, which matches anything,
|
|
/// with another that has more specific requirements based on the type of the
|
|
/// corresponding operand.
|
|
const char *TargetLowering::LowerXConstraint(EVT ConstraintVT) const{
|
|
if (ConstraintVT.isInteger())
|
|
return "r";
|
|
if (ConstraintVT.isFloatingPoint())
|
|
return "f"; // works for many targets
|
|
return nullptr;
|
|
}
|
|
|
|
/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
|
|
/// vector. If it is invalid, don't add anything to Ops.
|
|
void TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
|
|
std::string &Constraint,
|
|
std::vector<SDValue> &Ops,
|
|
SelectionDAG &DAG) const {
|
|
|
|
if (Constraint.length() > 1) return;
|
|
|
|
char ConstraintLetter = Constraint[0];
|
|
switch (ConstraintLetter) {
|
|
default: break;
|
|
case 'X': // Allows any operand; labels (basic block) use this.
|
|
if (Op.getOpcode() == ISD::BasicBlock) {
|
|
Ops.push_back(Op);
|
|
return;
|
|
}
|
|
// fall through
|
|
case 'i': // Simple Integer or Relocatable Constant
|
|
case 'n': // Simple Integer
|
|
case 's': { // Relocatable Constant
|
|
// These operands are interested in values of the form (GV+C), where C may
|
|
// be folded in as an offset of GV, or it may be explicitly added. Also, it
|
|
// is possible and fine if either GV or C are missing.
|
|
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
|
|
GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
|
|
|
|
// If we have "(add GV, C)", pull out GV/C
|
|
if (Op.getOpcode() == ISD::ADD) {
|
|
C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
|
|
GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0));
|
|
if (!C || !GA) {
|
|
C = dyn_cast<ConstantSDNode>(Op.getOperand(0));
|
|
GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1));
|
|
}
|
|
if (!C || !GA)
|
|
C = nullptr, GA = nullptr;
|
|
}
|
|
|
|
// If we find a valid operand, map to the TargetXXX version so that the
|
|
// value itself doesn't get selected.
|
|
if (GA) { // Either &GV or &GV+C
|
|
if (ConstraintLetter != 'n') {
|
|
int64_t Offs = GA->getOffset();
|
|
if (C) Offs += C->getZExtValue();
|
|
Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(),
|
|
C ? SDLoc(C) : SDLoc(),
|
|
Op.getValueType(), Offs));
|
|
return;
|
|
}
|
|
}
|
|
if (C) { // just C, no GV.
|
|
// Simple constants are not allowed for 's'.
|
|
if (ConstraintLetter != 's') {
|
|
// gcc prints these as sign extended. Sign extend value to 64 bits
|
|
// now; without this it would get ZExt'd later in
|
|
// ScheduleDAGSDNodes::EmitNode, which is very generic.
|
|
Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(),
|
|
MVT::i64));
|
|
return;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
|
|
getRegForInlineAsmConstraint(const std::string &Constraint,
|
|
MVT VT) const {
|
|
if (Constraint.empty() || Constraint[0] != '{')
|
|
return std::make_pair(0u, static_cast<TargetRegisterClass*>(nullptr));
|
|
assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");
|
|
|
|
// Remove the braces from around the name.
|
|
StringRef RegName(Constraint.data()+1, Constraint.size()-2);
|
|
|
|
std::pair<unsigned, const TargetRegisterClass*> R =
|
|
std::make_pair(0u, static_cast<const TargetRegisterClass*>(nullptr));
|
|
|
|
// Figure out which register class contains this reg.
|
|
const TargetRegisterInfo *RI =
|
|
getTargetMachine().getSubtargetImpl()->getRegisterInfo();
|
|
for (TargetRegisterInfo::regclass_iterator RCI = RI->regclass_begin(),
|
|
E = RI->regclass_end(); RCI != E; ++RCI) {
|
|
const TargetRegisterClass *RC = *RCI;
|
|
|
|
// If none of the value types for this register class are valid, we
|
|
// can't use it. For example, 64-bit reg classes on 32-bit targets.
|
|
if (!isLegalRC(RC))
|
|
continue;
|
|
|
|
for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
|
|
I != E; ++I) {
|
|
if (RegName.equals_lower(RI->getName(*I))) {
|
|
std::pair<unsigned, const TargetRegisterClass*> S =
|
|
std::make_pair(*I, RC);
|
|
|
|
// If this register class has the requested value type, return it,
|
|
// otherwise keep searching and return the first class found
|
|
// if no other is found which explicitly has the requested type.
|
|
if (RC->hasType(VT))
|
|
return S;
|
|
else if (!R.second)
|
|
R = S;
|
|
}
|
|
}
|
|
}
|
|
|
|
return R;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Constraint Selection.
|
|
|
|
/// isMatchingInputConstraint - Return true of this is an input operand that is
|
|
/// a matching constraint like "4".
|
|
bool TargetLowering::AsmOperandInfo::isMatchingInputConstraint() const {
|
|
assert(!ConstraintCode.empty() && "No known constraint!");
|
|
return isdigit(static_cast<unsigned char>(ConstraintCode[0]));
|
|
}
|
|
|
|
/// getMatchedOperand - If this is an input matching constraint, this method
|
|
/// returns the output operand it matches.
|
|
unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const {
|
|
assert(!ConstraintCode.empty() && "No known constraint!");
|
|
return atoi(ConstraintCode.c_str());
|
|
}
|
|
|
|
|
|
/// ParseConstraints - Split up the constraint string from the inline
|
|
/// assembly value into the specific constraints and their prefixes,
|
|
/// and also tie in the associated operand values.
|
|
/// If this returns an empty vector, and if the constraint string itself
|
|
/// isn't empty, there was an error parsing.
|
|
TargetLowering::AsmOperandInfoVector TargetLowering::ParseConstraints(
|
|
ImmutableCallSite CS) const {
|
|
/// ConstraintOperands - Information about all of the constraints.
|
|
AsmOperandInfoVector ConstraintOperands;
|
|
const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
|
|
unsigned maCount = 0; // Largest number of multiple alternative constraints.
|
|
|
|
// Do a prepass over the constraints, canonicalizing them, and building up the
|
|
// ConstraintOperands list.
|
|
unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
|
|
unsigned ResNo = 0; // ResNo - The result number of the next output.
|
|
|
|
for (InlineAsm::ConstraintInfo &CI : IA->ParseConstraints()) {
|
|
ConstraintOperands.emplace_back(std::move(CI));
|
|
AsmOperandInfo &OpInfo = ConstraintOperands.back();
|
|
|
|
// Update multiple alternative constraint count.
|
|
if (OpInfo.multipleAlternatives.size() > maCount)
|
|
maCount = OpInfo.multipleAlternatives.size();
|
|
|
|
OpInfo.ConstraintVT = MVT::Other;
|
|
|
|
// Compute the value type for each operand.
|
|
switch (OpInfo.Type) {
|
|
case InlineAsm::isOutput:
|
|
// Indirect outputs just consume an argument.
|
|
if (OpInfo.isIndirect) {
|
|
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
|
|
break;
|
|
}
|
|
|
|
// The return value of the call is this value. As such, there is no
|
|
// corresponding argument.
|
|
assert(!CS.getType()->isVoidTy() &&
|
|
"Bad inline asm!");
|
|
if (StructType *STy = dyn_cast<StructType>(CS.getType())) {
|
|
OpInfo.ConstraintVT = getSimpleValueType(STy->getElementType(ResNo));
|
|
} else {
|
|
assert(ResNo == 0 && "Asm only has one result!");
|
|
OpInfo.ConstraintVT = getSimpleValueType(CS.getType());
|
|
}
|
|
++ResNo;
|
|
break;
|
|
case InlineAsm::isInput:
|
|
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
|
|
break;
|
|
case InlineAsm::isClobber:
|
|
// Nothing to do.
|
|
break;
|
|
}
|
|
|
|
if (OpInfo.CallOperandVal) {
|
|
llvm::Type *OpTy = OpInfo.CallOperandVal->getType();
|
|
if (OpInfo.isIndirect) {
|
|
llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy);
|
|
if (!PtrTy)
|
|
report_fatal_error("Indirect operand for inline asm not a pointer!");
|
|
OpTy = PtrTy->getElementType();
|
|
}
|
|
|
|
// Look for vector wrapped in a struct. e.g. { <16 x i8> }.
|
|
if (StructType *STy = dyn_cast<StructType>(OpTy))
|
|
if (STy->getNumElements() == 1)
|
|
OpTy = STy->getElementType(0);
|
|
|
|
// If OpTy is not a single value, it may be a struct/union that we
|
|
// can tile with integers.
|
|
if (!OpTy->isSingleValueType() && OpTy->isSized()) {
|
|
unsigned BitSize = getDataLayout()->getTypeSizeInBits(OpTy);
|
|
switch (BitSize) {
|
|
default: break;
|
|
case 1:
|
|
case 8:
|
|
case 16:
|
|
case 32:
|
|
case 64:
|
|
case 128:
|
|
OpInfo.ConstraintVT =
|
|
MVT::getVT(IntegerType::get(OpTy->getContext(), BitSize), true);
|
|
break;
|
|
}
|
|
} else if (PointerType *PT = dyn_cast<PointerType>(OpTy)) {
|
|
unsigned PtrSize
|
|
= getDataLayout()->getPointerSizeInBits(PT->getAddressSpace());
|
|
OpInfo.ConstraintVT = MVT::getIntegerVT(PtrSize);
|
|
} else {
|
|
OpInfo.ConstraintVT = MVT::getVT(OpTy, true);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If we have multiple alternative constraints, select the best alternative.
|
|
if (!ConstraintOperands.empty()) {
|
|
if (maCount) {
|
|
unsigned bestMAIndex = 0;
|
|
int bestWeight = -1;
|
|
// weight: -1 = invalid match, and 0 = so-so match to 5 = good match.
|
|
int weight = -1;
|
|
unsigned maIndex;
|
|
// Compute the sums of the weights for each alternative, keeping track
|
|
// of the best (highest weight) one so far.
|
|
for (maIndex = 0; maIndex < maCount; ++maIndex) {
|
|
int weightSum = 0;
|
|
for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
|
|
cIndex != eIndex; ++cIndex) {
|
|
AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
|
|
if (OpInfo.Type == InlineAsm::isClobber)
|
|
continue;
|
|
|
|
// If this is an output operand with a matching input operand,
|
|
// look up the matching input. If their types mismatch, e.g. one
|
|
// is an integer, the other is floating point, or their sizes are
|
|
// different, flag it as an maCantMatch.
|
|
if (OpInfo.hasMatchingInput()) {
|
|
AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
|
|
if (OpInfo.ConstraintVT != Input.ConstraintVT) {
|
|
if ((OpInfo.ConstraintVT.isInteger() !=
|
|
Input.ConstraintVT.isInteger()) ||
|
|
(OpInfo.ConstraintVT.getSizeInBits() !=
|
|
Input.ConstraintVT.getSizeInBits())) {
|
|
weightSum = -1; // Can't match.
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
weight = getMultipleConstraintMatchWeight(OpInfo, maIndex);
|
|
if (weight == -1) {
|
|
weightSum = -1;
|
|
break;
|
|
}
|
|
weightSum += weight;
|
|
}
|
|
// Update best.
|
|
if (weightSum > bestWeight) {
|
|
bestWeight = weightSum;
|
|
bestMAIndex = maIndex;
|
|
}
|
|
}
|
|
|
|
// Now select chosen alternative in each constraint.
|
|
for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
|
|
cIndex != eIndex; ++cIndex) {
|
|
AsmOperandInfo& cInfo = ConstraintOperands[cIndex];
|
|
if (cInfo.Type == InlineAsm::isClobber)
|
|
continue;
|
|
cInfo.selectAlternative(bestMAIndex);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Check and hook up tied operands, choose constraint code to use.
|
|
for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
|
|
cIndex != eIndex; ++cIndex) {
|
|
AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
|
|
|
|
// If this is an output operand with a matching input operand, look up the
|
|
// matching input. If their types mismatch, e.g. one is an integer, the
|
|
// other is floating point, or their sizes are different, flag it as an
|
|
// error.
|
|
if (OpInfo.hasMatchingInput()) {
|
|
AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
|
|
|
|
if (OpInfo.ConstraintVT != Input.ConstraintVT) {
|
|
std::pair<unsigned, const TargetRegisterClass*> MatchRC =
|
|
getRegForInlineAsmConstraint(OpInfo.ConstraintCode,
|
|
OpInfo.ConstraintVT);
|
|
std::pair<unsigned, const TargetRegisterClass*> InputRC =
|
|
getRegForInlineAsmConstraint(Input.ConstraintCode,
|
|
Input.ConstraintVT);
|
|
if ((OpInfo.ConstraintVT.isInteger() !=
|
|
Input.ConstraintVT.isInteger()) ||
|
|
(MatchRC.second != InputRC.second)) {
|
|
report_fatal_error("Unsupported asm: input constraint"
|
|
" with a matching output constraint of"
|
|
" incompatible type!");
|
|
}
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
return ConstraintOperands;
|
|
}
|
|
|
|
|
|
/// getConstraintGenerality - Return an integer indicating how general CT
|
|
/// is.
|
|
static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {
|
|
switch (CT) {
|
|
case TargetLowering::C_Other:
|
|
case TargetLowering::C_Unknown:
|
|
return 0;
|
|
case TargetLowering::C_Register:
|
|
return 1;
|
|
case TargetLowering::C_RegisterClass:
|
|
return 2;
|
|
case TargetLowering::C_Memory:
|
|
return 3;
|
|
}
|
|
llvm_unreachable("Invalid constraint type");
|
|
}
|
|
|
|
/// Examine constraint type and operand type and determine a weight value.
|
|
/// This object must already have been set up with the operand type
|
|
/// and the current alternative constraint selected.
|
|
TargetLowering::ConstraintWeight
|
|
TargetLowering::getMultipleConstraintMatchWeight(
|
|
AsmOperandInfo &info, int maIndex) const {
|
|
InlineAsm::ConstraintCodeVector *rCodes;
|
|
if (maIndex >= (int)info.multipleAlternatives.size())
|
|
rCodes = &info.Codes;
|
|
else
|
|
rCodes = &info.multipleAlternatives[maIndex].Codes;
|
|
ConstraintWeight BestWeight = CW_Invalid;
|
|
|
|
// Loop over the options, keeping track of the most general one.
|
|
for (unsigned i = 0, e = rCodes->size(); i != e; ++i) {
|
|
ConstraintWeight weight =
|
|
getSingleConstraintMatchWeight(info, (*rCodes)[i].c_str());
|
|
if (weight > BestWeight)
|
|
BestWeight = weight;
|
|
}
|
|
|
|
return BestWeight;
|
|
}
|
|
|
|
/// Examine constraint type and operand type and determine a weight value.
|
|
/// This object must already have been set up with the operand type
|
|
/// and the current alternative constraint selected.
|
|
TargetLowering::ConstraintWeight
|
|
TargetLowering::getSingleConstraintMatchWeight(
|
|
AsmOperandInfo &info, const char *constraint) const {
|
|
ConstraintWeight weight = CW_Invalid;
|
|
Value *CallOperandVal = info.CallOperandVal;
|
|
// If we don't have a value, we can't do a match,
|
|
// but allow it at the lowest weight.
|
|
if (!CallOperandVal)
|
|
return CW_Default;
|
|
// Look at the constraint type.
|
|
switch (*constraint) {
|
|
case 'i': // immediate integer.
|
|
case 'n': // immediate integer with a known value.
|
|
if (isa<ConstantInt>(CallOperandVal))
|
|
weight = CW_Constant;
|
|
break;
|
|
case 's': // non-explicit intregal immediate.
|
|
if (isa<GlobalValue>(CallOperandVal))
|
|
weight = CW_Constant;
|
|
break;
|
|
case 'E': // immediate float if host format.
|
|
case 'F': // immediate float.
|
|
if (isa<ConstantFP>(CallOperandVal))
|
|
weight = CW_Constant;
|
|
break;
|
|
case '<': // memory operand with autodecrement.
|
|
case '>': // memory operand with autoincrement.
|
|
case 'm': // memory operand.
|
|
case 'o': // offsettable memory operand
|
|
case 'V': // non-offsettable memory operand
|
|
weight = CW_Memory;
|
|
break;
|
|
case 'r': // general register.
|
|
case 'g': // general register, memory operand or immediate integer.
|
|
// note: Clang converts "g" to "imr".
|
|
if (CallOperandVal->getType()->isIntegerTy())
|
|
weight = CW_Register;
|
|
break;
|
|
case 'X': // any operand.
|
|
default:
|
|
weight = CW_Default;
|
|
break;
|
|
}
|
|
return weight;
|
|
}
|
|
|
|
/// ChooseConstraint - If there are multiple different constraints that we
|
|
/// could pick for this operand (e.g. "imr") try to pick the 'best' one.
|
|
/// This is somewhat tricky: constraints fall into four classes:
|
|
/// Other -> immediates and magic values
|
|
/// Register -> one specific register
|
|
/// RegisterClass -> a group of regs
|
|
/// Memory -> memory
|
|
/// Ideally, we would pick the most specific constraint possible: if we have
|
|
/// something that fits into a register, we would pick it. The problem here
|
|
/// is that if we have something that could either be in a register or in
|
|
/// memory that use of the register could cause selection of *other*
|
|
/// operands to fail: they might only succeed if we pick memory. Because of
|
|
/// this the heuristic we use is:
|
|
///
|
|
/// 1) If there is an 'other' constraint, and if the operand is valid for
|
|
/// that constraint, use it. This makes us take advantage of 'i'
|
|
/// constraints when available.
|
|
/// 2) Otherwise, pick the most general constraint present. This prefers
|
|
/// 'm' over 'r', for example.
|
|
///
|
|
static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo,
|
|
const TargetLowering &TLI,
|
|
SDValue Op, SelectionDAG *DAG) {
|
|
assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options");
|
|
unsigned BestIdx = 0;
|
|
TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown;
|
|
int BestGenerality = -1;
|
|
|
|
// Loop over the options, keeping track of the most general one.
|
|
for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) {
|
|
TargetLowering::ConstraintType CType =
|
|
TLI.getConstraintType(OpInfo.Codes[i]);
|
|
|
|
// If this is an 'other' constraint, see if the operand is valid for it.
|
|
// For example, on X86 we might have an 'rI' constraint. If the operand
|
|
// is an integer in the range [0..31] we want to use I (saving a load
|
|
// of a register), otherwise we must use 'r'.
|
|
if (CType == TargetLowering::C_Other && Op.getNode()) {
|
|
assert(OpInfo.Codes[i].size() == 1 &&
|
|
"Unhandled multi-letter 'other' constraint");
|
|
std::vector<SDValue> ResultOps;
|
|
TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i],
|
|
ResultOps, *DAG);
|
|
if (!ResultOps.empty()) {
|
|
BestType = CType;
|
|
BestIdx = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Things with matching constraints can only be registers, per gcc
|
|
// documentation. This mainly affects "g" constraints.
|
|
if (CType == TargetLowering::C_Memory && OpInfo.hasMatchingInput())
|
|
continue;
|
|
|
|
// This constraint letter is more general than the previous one, use it.
|
|
int Generality = getConstraintGenerality(CType);
|
|
if (Generality > BestGenerality) {
|
|
BestType = CType;
|
|
BestIdx = i;
|
|
BestGenerality = Generality;
|
|
}
|
|
}
|
|
|
|
OpInfo.ConstraintCode = OpInfo.Codes[BestIdx];
|
|
OpInfo.ConstraintType = BestType;
|
|
}
|
|
|
|
/// ComputeConstraintToUse - Determines the constraint code and constraint
|
|
/// type to use for the specific AsmOperandInfo, setting
|
|
/// OpInfo.ConstraintCode and OpInfo.ConstraintType.
|
|
void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo,
|
|
SDValue Op,
|
|
SelectionDAG *DAG) const {
|
|
assert(!OpInfo.Codes.empty() && "Must have at least one constraint");
|
|
|
|
// Single-letter constraints ('r') are very common.
|
|
if (OpInfo.Codes.size() == 1) {
|
|
OpInfo.ConstraintCode = OpInfo.Codes[0];
|
|
OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
|
|
} else {
|
|
ChooseConstraint(OpInfo, *this, Op, DAG);
|
|
}
|
|
|
|
// 'X' matches anything.
|
|
if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) {
|
|
// Labels and constants are handled elsewhere ('X' is the only thing
|
|
// that matches labels). For Functions, the type here is the type of
|
|
// the result, which is not what we want to look at; leave them alone.
|
|
Value *v = OpInfo.CallOperandVal;
|
|
if (isa<BasicBlock>(v) || isa<ConstantInt>(v) || isa<Function>(v)) {
|
|
OpInfo.CallOperandVal = v;
|
|
return;
|
|
}
|
|
|
|
// Otherwise, try to resolve it to something we know about by looking at
|
|
// the actual operand type.
|
|
if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) {
|
|
OpInfo.ConstraintCode = Repl;
|
|
OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// \brief Given an exact SDIV by a constant, create a multiplication
|
|
/// with the multiplicative inverse of the constant.
|
|
SDValue TargetLowering::BuildExactSDIV(SDValue Op1, SDValue Op2, SDLoc dl,
|
|
SelectionDAG &DAG) const {
|
|
ConstantSDNode *C = cast<ConstantSDNode>(Op2);
|
|
APInt d = C->getAPIntValue();
|
|
assert(d != 0 && "Division by zero!");
|
|
|
|
// Shift the value upfront if it is even, so the LSB is one.
|
|
unsigned ShAmt = d.countTrailingZeros();
|
|
if (ShAmt) {
|
|
// TODO: For UDIV use SRL instead of SRA.
|
|
SDValue Amt = DAG.getConstant(ShAmt, getShiftAmountTy(Op1.getValueType()));
|
|
Op1 = DAG.getNode(ISD::SRA, dl, Op1.getValueType(), Op1, Amt, false, false,
|
|
true);
|
|
d = d.ashr(ShAmt);
|
|
}
|
|
|
|
// Calculate the multiplicative inverse, using Newton's method.
|
|
APInt t, xn = d;
|
|
while ((t = d*xn) != 1)
|
|
xn *= APInt(d.getBitWidth(), 2) - t;
|
|
|
|
Op2 = DAG.getConstant(xn, Op1.getValueType());
|
|
return DAG.getNode(ISD::MUL, dl, Op1.getValueType(), Op1, Op2);
|
|
}
|
|
|
|
/// \brief Given an ISD::SDIV node expressing a divide by constant,
|
|
/// return a DAG expression to select that will generate the same value by
|
|
/// multiplying by a magic number.
|
|
/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
|
|
SDValue TargetLowering::BuildSDIV(SDNode *N, const APInt &Divisor,
|
|
SelectionDAG &DAG, bool IsAfterLegalization,
|
|
std::vector<SDNode *> *Created) const {
|
|
assert(Created && "No vector to hold sdiv ops.");
|
|
|
|
EVT VT = N->getValueType(0);
|
|
SDLoc dl(N);
|
|
|
|
// Check to see if we can do this.
|
|
// FIXME: We should be more aggressive here.
|
|
if (!isTypeLegal(VT))
|
|
return SDValue();
|
|
|
|
APInt::ms magics = Divisor.magic();
|
|
|
|
// Multiply the numerator (operand 0) by the magic value
|
|
// FIXME: We should support doing a MUL in a wider type
|
|
SDValue Q;
|
|
if (IsAfterLegalization ? isOperationLegal(ISD::MULHS, VT) :
|
|
isOperationLegalOrCustom(ISD::MULHS, VT))
|
|
Q = DAG.getNode(ISD::MULHS, dl, VT, N->getOperand(0),
|
|
DAG.getConstant(magics.m, VT));
|
|
else if (IsAfterLegalization ? isOperationLegal(ISD::SMUL_LOHI, VT) :
|
|
isOperationLegalOrCustom(ISD::SMUL_LOHI, VT))
|
|
Q = SDValue(DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(VT, VT),
|
|
N->getOperand(0),
|
|
DAG.getConstant(magics.m, VT)).getNode(), 1);
|
|
else
|
|
return SDValue(); // No mulhs or equvialent
|
|
// If d > 0 and m < 0, add the numerator
|
|
if (Divisor.isStrictlyPositive() && magics.m.isNegative()) {
|
|
Q = DAG.getNode(ISD::ADD, dl, VT, Q, N->getOperand(0));
|
|
Created->push_back(Q.getNode());
|
|
}
|
|
// If d < 0 and m > 0, subtract the numerator.
|
|
if (Divisor.isNegative() && magics.m.isStrictlyPositive()) {
|
|
Q = DAG.getNode(ISD::SUB, dl, VT, Q, N->getOperand(0));
|
|
Created->push_back(Q.getNode());
|
|
}
|
|
// Shift right algebraic if shift value is nonzero
|
|
if (magics.s > 0) {
|
|
Q = DAG.getNode(ISD::SRA, dl, VT, Q,
|
|
DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType())));
|
|
Created->push_back(Q.getNode());
|
|
}
|
|
// Extract the sign bit and add it to the quotient
|
|
SDValue T = DAG.getNode(ISD::SRL, dl, VT, Q,
|
|
DAG.getConstant(VT.getScalarSizeInBits() - 1,
|
|
getShiftAmountTy(Q.getValueType())));
|
|
Created->push_back(T.getNode());
|
|
return DAG.getNode(ISD::ADD, dl, VT, Q, T);
|
|
}
|
|
|
|
/// \brief Given an ISD::UDIV node expressing a divide by constant,
|
|
/// return a DAG expression to select that will generate the same value by
|
|
/// multiplying by a magic number.
|
|
/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
|
|
SDValue TargetLowering::BuildUDIV(SDNode *N, const APInt &Divisor,
|
|
SelectionDAG &DAG, bool IsAfterLegalization,
|
|
std::vector<SDNode *> *Created) const {
|
|
assert(Created && "No vector to hold udiv ops.");
|
|
|
|
EVT VT = N->getValueType(0);
|
|
SDLoc dl(N);
|
|
|
|
// Check to see if we can do this.
|
|
// FIXME: We should be more aggressive here.
|
|
if (!isTypeLegal(VT))
|
|
return SDValue();
|
|
|
|
// FIXME: We should use a narrower constant when the upper
|
|
// bits are known to be zero.
|
|
APInt::mu magics = Divisor.magicu();
|
|
|
|
SDValue Q = N->getOperand(0);
|
|
|
|
// If the divisor is even, we can avoid using the expensive fixup by shifting
|
|
// the divided value upfront.
|
|
if (magics.a != 0 && !Divisor[0]) {
|
|
unsigned Shift = Divisor.countTrailingZeros();
|
|
Q = DAG.getNode(ISD::SRL, dl, VT, Q,
|
|
DAG.getConstant(Shift, getShiftAmountTy(Q.getValueType())));
|
|
Created->push_back(Q.getNode());
|
|
|
|
// Get magic number for the shifted divisor.
|
|
magics = Divisor.lshr(Shift).magicu(Shift);
|
|
assert(magics.a == 0 && "Should use cheap fixup now");
|
|
}
|
|
|
|
// Multiply the numerator (operand 0) by the magic value
|
|
// FIXME: We should support doing a MUL in a wider type
|
|
if (IsAfterLegalization ? isOperationLegal(ISD::MULHU, VT) :
|
|
isOperationLegalOrCustom(ISD::MULHU, VT))
|
|
Q = DAG.getNode(ISD::MULHU, dl, VT, Q, DAG.getConstant(magics.m, VT));
|
|
else if (IsAfterLegalization ? isOperationLegal(ISD::UMUL_LOHI, VT) :
|
|
isOperationLegalOrCustom(ISD::UMUL_LOHI, VT))
|
|
Q = SDValue(DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(VT, VT), Q,
|
|
DAG.getConstant(magics.m, VT)).getNode(), 1);
|
|
else
|
|
return SDValue(); // No mulhu or equvialent
|
|
|
|
Created->push_back(Q.getNode());
|
|
|
|
if (magics.a == 0) {
|
|
assert(magics.s < Divisor.getBitWidth() &&
|
|
"We shouldn't generate an undefined shift!");
|
|
return DAG.getNode(ISD::SRL, dl, VT, Q,
|
|
DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType())));
|
|
} else {
|
|
SDValue NPQ = DAG.getNode(ISD::SUB, dl, VT, N->getOperand(0), Q);
|
|
Created->push_back(NPQ.getNode());
|
|
NPQ = DAG.getNode(ISD::SRL, dl, VT, NPQ,
|
|
DAG.getConstant(1, getShiftAmountTy(NPQ.getValueType())));
|
|
Created->push_back(NPQ.getNode());
|
|
NPQ = DAG.getNode(ISD::ADD, dl, VT, NPQ, Q);
|
|
Created->push_back(NPQ.getNode());
|
|
return DAG.getNode(ISD::SRL, dl, VT, NPQ,
|
|
DAG.getConstant(magics.s-1, getShiftAmountTy(NPQ.getValueType())));
|
|
}
|
|
}
|
|
|
|
bool TargetLowering::
|
|
verifyReturnAddressArgumentIsConstant(SDValue Op, SelectionDAG &DAG) const {
|
|
if (!isa<ConstantSDNode>(Op.getOperand(0))) {
|
|
DAG.getContext()->emitError("argument to '__builtin_return_address' must "
|
|
"be a constant integer");
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Legalization Utilities
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
bool TargetLowering::expandMUL(SDNode *N, SDValue &Lo, SDValue &Hi, EVT HiLoVT,
|
|
SelectionDAG &DAG, SDValue LL, SDValue LH,
|
|
SDValue RL, SDValue RH) const {
|
|
EVT VT = N->getValueType(0);
|
|
SDLoc dl(N);
|
|
|
|
bool HasMULHS = isOperationLegalOrCustom(ISD::MULHS, HiLoVT);
|
|
bool HasMULHU = isOperationLegalOrCustom(ISD::MULHU, HiLoVT);
|
|
bool HasSMUL_LOHI = isOperationLegalOrCustom(ISD::SMUL_LOHI, HiLoVT);
|
|
bool HasUMUL_LOHI = isOperationLegalOrCustom(ISD::UMUL_LOHI, HiLoVT);
|
|
if (HasMULHU || HasMULHS || HasUMUL_LOHI || HasSMUL_LOHI) {
|
|
unsigned OuterBitSize = VT.getSizeInBits();
|
|
unsigned InnerBitSize = HiLoVT.getSizeInBits();
|
|
unsigned LHSSB = DAG.ComputeNumSignBits(N->getOperand(0));
|
|
unsigned RHSSB = DAG.ComputeNumSignBits(N->getOperand(1));
|
|
|
|
// LL, LH, RL, and RH must be either all NULL or all set to a value.
|
|
assert((LL.getNode() && LH.getNode() && RL.getNode() && RH.getNode()) ||
|
|
(!LL.getNode() && !LH.getNode() && !RL.getNode() && !RH.getNode()));
|
|
|
|
if (!LL.getNode() && !RL.getNode() &&
|
|
isOperationLegalOrCustom(ISD::TRUNCATE, HiLoVT)) {
|
|
LL = DAG.getNode(ISD::TRUNCATE, dl, HiLoVT, N->getOperand(0));
|
|
RL = DAG.getNode(ISD::TRUNCATE, dl, HiLoVT, N->getOperand(1));
|
|
}
|
|
|
|
if (!LL.getNode())
|
|
return false;
|
|
|
|
APInt HighMask = APInt::getHighBitsSet(OuterBitSize, InnerBitSize);
|
|
if (DAG.MaskedValueIsZero(N->getOperand(0), HighMask) &&
|
|
DAG.MaskedValueIsZero(N->getOperand(1), HighMask)) {
|
|
// The inputs are both zero-extended.
|
|
if (HasUMUL_LOHI) {
|
|
// We can emit a umul_lohi.
|
|
Lo = DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(HiLoVT, HiLoVT), LL,
|
|
RL);
|
|
Hi = SDValue(Lo.getNode(), 1);
|
|
return true;
|
|
}
|
|
if (HasMULHU) {
|
|
// We can emit a mulhu+mul.
|
|
Lo = DAG.getNode(ISD::MUL, dl, HiLoVT, LL, RL);
|
|
Hi = DAG.getNode(ISD::MULHU, dl, HiLoVT, LL, RL);
|
|
return true;
|
|
}
|
|
}
|
|
if (LHSSB > InnerBitSize && RHSSB > InnerBitSize) {
|
|
// The input values are both sign-extended.
|
|
if (HasSMUL_LOHI) {
|
|
// We can emit a smul_lohi.
|
|
Lo = DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(HiLoVT, HiLoVT), LL,
|
|
RL);
|
|
Hi = SDValue(Lo.getNode(), 1);
|
|
return true;
|
|
}
|
|
if (HasMULHS) {
|
|
// We can emit a mulhs+mul.
|
|
Lo = DAG.getNode(ISD::MUL, dl, HiLoVT, LL, RL);
|
|
Hi = DAG.getNode(ISD::MULHS, dl, HiLoVT, LL, RL);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
if (!LH.getNode() && !RH.getNode() &&
|
|
isOperationLegalOrCustom(ISD::SRL, VT) &&
|
|
isOperationLegalOrCustom(ISD::TRUNCATE, HiLoVT)) {
|
|
unsigned ShiftAmt = VT.getSizeInBits() - HiLoVT.getSizeInBits();
|
|
SDValue Shift = DAG.getConstant(ShiftAmt, getShiftAmountTy(VT));
|
|
LH = DAG.getNode(ISD::SRL, dl, VT, N->getOperand(0), Shift);
|
|
LH = DAG.getNode(ISD::TRUNCATE, dl, HiLoVT, LH);
|
|
RH = DAG.getNode(ISD::SRL, dl, VT, N->getOperand(1), Shift);
|
|
RH = DAG.getNode(ISD::TRUNCATE, dl, HiLoVT, RH);
|
|
}
|
|
|
|
if (!LH.getNode())
|
|
return false;
|
|
|
|
if (HasUMUL_LOHI) {
|
|
// Lo,Hi = umul LHS, RHS.
|
|
SDValue UMulLOHI = DAG.getNode(ISD::UMUL_LOHI, dl,
|
|
DAG.getVTList(HiLoVT, HiLoVT), LL, RL);
|
|
Lo = UMulLOHI;
|
|
Hi = UMulLOHI.getValue(1);
|
|
RH = DAG.getNode(ISD::MUL, dl, HiLoVT, LL, RH);
|
|
LH = DAG.getNode(ISD::MUL, dl, HiLoVT, LH, RL);
|
|
Hi = DAG.getNode(ISD::ADD, dl, HiLoVT, Hi, RH);
|
|
Hi = DAG.getNode(ISD::ADD, dl, HiLoVT, Hi, LH);
|
|
return true;
|
|
}
|
|
if (HasMULHU) {
|
|
Lo = DAG.getNode(ISD::MUL, dl, HiLoVT, LL, RL);
|
|
Hi = DAG.getNode(ISD::MULHU, dl, HiLoVT, LL, RL);
|
|
RH = DAG.getNode(ISD::MUL, dl, HiLoVT, LL, RH);
|
|
LH = DAG.getNode(ISD::MUL, dl, HiLoVT, LH, RL);
|
|
Hi = DAG.getNode(ISD::ADD, dl, HiLoVT, Hi, RH);
|
|
Hi = DAG.getNode(ISD::ADD, dl, HiLoVT, Hi, LH);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool TargetLowering::expandFP_TO_SINT(SDNode *Node, SDValue &Result,
|
|
SelectionDAG &DAG) const {
|
|
EVT VT = Node->getOperand(0).getValueType();
|
|
EVT NVT = Node->getValueType(0);
|
|
SDLoc dl(SDValue(Node, 0));
|
|
|
|
// FIXME: Only f32 to i64 conversions are supported.
|
|
if (VT != MVT::f32 || NVT != MVT::i64)
|
|
return false;
|
|
|
|
// Expand f32 -> i64 conversion
|
|
// This algorithm comes from compiler-rt's implementation of fixsfdi:
|
|
// https://github.com/llvm-mirror/compiler-rt/blob/master/lib/builtins/fixsfdi.c
|
|
EVT IntVT = EVT::getIntegerVT(*DAG.getContext(),
|
|
VT.getSizeInBits());
|
|
SDValue ExponentMask = DAG.getConstant(0x7F800000, IntVT);
|
|
SDValue ExponentLoBit = DAG.getConstant(23, IntVT);
|
|
SDValue Bias = DAG.getConstant(127, IntVT);
|
|
SDValue SignMask = DAG.getConstant(APInt::getSignBit(VT.getSizeInBits()),
|
|
IntVT);
|
|
SDValue SignLowBit = DAG.getConstant(VT.getSizeInBits() - 1, IntVT);
|
|
SDValue MantissaMask = DAG.getConstant(0x007FFFFF, IntVT);
|
|
|
|
SDValue Bits = DAG.getNode(ISD::BITCAST, dl, IntVT, Node->getOperand(0));
|
|
|
|
SDValue ExponentBits = DAG.getNode(ISD::SRL, dl, IntVT,
|
|
DAG.getNode(ISD::AND, dl, IntVT, Bits, ExponentMask),
|
|
DAG.getZExtOrTrunc(ExponentLoBit, dl, getShiftAmountTy(IntVT)));
|
|
SDValue Exponent = DAG.getNode(ISD::SUB, dl, IntVT, ExponentBits, Bias);
|
|
|
|
SDValue Sign = DAG.getNode(ISD::SRA, dl, IntVT,
|
|
DAG.getNode(ISD::AND, dl, IntVT, Bits, SignMask),
|
|
DAG.getZExtOrTrunc(SignLowBit, dl, getShiftAmountTy(IntVT)));
|
|
Sign = DAG.getSExtOrTrunc(Sign, dl, NVT);
|
|
|
|
SDValue R = DAG.getNode(ISD::OR, dl, IntVT,
|
|
DAG.getNode(ISD::AND, dl, IntVT, Bits, MantissaMask),
|
|
DAG.getConstant(0x00800000, IntVT));
|
|
|
|
R = DAG.getZExtOrTrunc(R, dl, NVT);
|
|
|
|
|
|
R = DAG.getSelectCC(dl, Exponent, ExponentLoBit,
|
|
DAG.getNode(ISD::SHL, dl, NVT, R,
|
|
DAG.getZExtOrTrunc(
|
|
DAG.getNode(ISD::SUB, dl, IntVT, Exponent, ExponentLoBit),
|
|
dl, getShiftAmountTy(IntVT))),
|
|
DAG.getNode(ISD::SRL, dl, NVT, R,
|
|
DAG.getZExtOrTrunc(
|
|
DAG.getNode(ISD::SUB, dl, IntVT, ExponentLoBit, Exponent),
|
|
dl, getShiftAmountTy(IntVT))),
|
|
ISD::SETGT);
|
|
|
|
SDValue Ret = DAG.getNode(ISD::SUB, dl, NVT,
|
|
DAG.getNode(ISD::XOR, dl, NVT, R, Sign),
|
|
Sign);
|
|
|
|
Result = DAG.getSelectCC(dl, Exponent, DAG.getConstant(0, IntVT),
|
|
DAG.getConstant(0, NVT), Ret, ISD::SETLT);
|
|
return true;
|
|
}
|