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llvm-6502/lib/Target/PowerPC/PPCISelLowering.cpp
Chris Lattner bba534dc66 Make llvm.frame/returnaddr not crash on ppc 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25710 91177308-0d34-0410-b5e6-96231b3b80d8
2006-01-27 22:25:06 +00:00

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//===-- PPCISelLowering.cpp - PPC DAG Lowering Implementation -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the PPCISelLowering class.
//
//===----------------------------------------------------------------------===//
#include "PPCISelLowering.h"
#include "PPCTargetMachine.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
using namespace llvm;
PPCTargetLowering::PPCTargetLowering(TargetMachine &TM)
: TargetLowering(TM) {
// Fold away setcc operations if possible.
setSetCCIsExpensive();
setPow2DivIsCheap();
// Use _setjmp/_longjmp instead of setjmp/longjmp.
setUseUnderscoreSetJmpLongJmp(true);
// Set up the register classes.
addRegisterClass(MVT::i32, PPC::GPRCRegisterClass);
addRegisterClass(MVT::f32, PPC::F4RCRegisterClass);
addRegisterClass(MVT::f64, PPC::F8RCRegisterClass);
// PowerPC has no intrinsics for these particular operations
setOperationAction(ISD::MEMMOVE, MVT::Other, Expand);
setOperationAction(ISD::MEMSET, MVT::Other, Expand);
setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
// PowerPC has an i16 but no i8 (or i1) SEXTLOAD
setOperationAction(ISD::SEXTLOAD, MVT::i1, Expand);
setOperationAction(ISD::SEXTLOAD, MVT::i8, Expand);
// PowerPC has no SREM/UREM instructions
setOperationAction(ISD::SREM, MVT::i32, Expand);
setOperationAction(ISD::UREM, MVT::i32, Expand);
// We don't support sin/cos/sqrt/fmod
setOperationAction(ISD::FSIN , MVT::f64, Expand);
setOperationAction(ISD::FCOS , MVT::f64, Expand);
setOperationAction(ISD::FREM , MVT::f64, Expand);
setOperationAction(ISD::FSIN , MVT::f32, Expand);
setOperationAction(ISD::FCOS , MVT::f32, Expand);
setOperationAction(ISD::FREM , MVT::f32, Expand);
// If we're enabling GP optimizations, use hardware square root
if (!TM.getSubtarget<PPCSubtarget>().hasFSQRT()) {
setOperationAction(ISD::FSQRT, MVT::f64, Expand);
setOperationAction(ISD::FSQRT, MVT::f32, Expand);
}
// PowerPC does not have BSWAP, CTPOP or CTTZ
setOperationAction(ISD::BSWAP, MVT::i32 , Expand);
setOperationAction(ISD::CTPOP, MVT::i32 , Expand);
setOperationAction(ISD::CTTZ , MVT::i32 , Expand);
// PowerPC does not have ROTR
setOperationAction(ISD::ROTR, MVT::i32 , Expand);
// PowerPC does not have Select
setOperationAction(ISD::SELECT, MVT::i32, Expand);
setOperationAction(ISD::SELECT, MVT::f32, Expand);
setOperationAction(ISD::SELECT, MVT::f64, Expand);
// PowerPC wants to turn select_cc of FP into fsel when possible.
setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
// PowerPC does not have BRCOND* which requires SetCC
setOperationAction(ISD::BRCOND, MVT::Other, Expand);
setOperationAction(ISD::BRCONDTWOWAY, MVT::Other, Expand);
// PowerPC turns FP_TO_SINT into FCTIWZ and some load/stores.
setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
// PowerPC does not have [U|S]INT_TO_FP
setOperationAction(ISD::SINT_TO_FP, MVT::i32, Expand);
setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand);
setOperationAction(ISD::BIT_CONVERT, MVT::f32, Expand);
setOperationAction(ISD::BIT_CONVERT, MVT::i32, Expand);
// PowerPC does not have truncstore for i1.
setOperationAction(ISD::TRUNCSTORE, MVT::i1, Promote);
// Support label based line numbers.
setOperationAction(ISD::LOCATION, MVT::Other, Expand);
setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
// FIXME - use subtarget debug flags
if (!TM.getSubtarget<PPCSubtarget>().isDarwin())
setOperationAction(ISD::DEBUG_LABEL, MVT::Other, Expand);
// We want to legalize GlobalAddress and ConstantPool nodes into the
// appropriate instructions to materialize the address.
setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
setOperationAction(ISD::ConstantPool, MVT::i32, Custom);
// RET must be custom lowered, to meet ABI requirements
setOperationAction(ISD::RET , MVT::Other, Custom);
// VASTART needs to be custom lowered to use the VarArgsFrameIndex
setOperationAction(ISD::VASTART , MVT::Other, Custom);
// Use the default implementation.
setOperationAction(ISD::VAARG , MVT::Other, Expand);
setOperationAction(ISD::VACOPY , MVT::Other, Expand);
setOperationAction(ISD::VAEND , MVT::Other, Expand);
setOperationAction(ISD::STACKSAVE , MVT::Other, Expand);
setOperationAction(ISD::STACKRESTORE , MVT::Other, Expand);
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32 , Expand);
if (TM.getSubtarget<PPCSubtarget>().is64Bit()) {
// They also have instructions for converting between i64 and fp.
setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
// To take advantage of the above i64 FP_TO_SINT, promote i32 FP_TO_UINT
setOperationAction(ISD::FP_TO_UINT, MVT::i32, Promote);
} else {
// PowerPC does not have FP_TO_UINT on 32-bit implementations.
setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
}
if (TM.getSubtarget<PPCSubtarget>().has64BitRegs()) {
// 64 bit PowerPC implementations can support i64 types directly
addRegisterClass(MVT::i64, PPC::G8RCRegisterClass);
// BUILD_PAIR can't be handled natively, and should be expanded to shl/or
setOperationAction(ISD::BUILD_PAIR, MVT::i64, Expand);
} else {
// 32 bit PowerPC wants to expand i64 shifts itself.
setOperationAction(ISD::SHL, MVT::i64, Custom);
setOperationAction(ISD::SRL, MVT::i64, Custom);
setOperationAction(ISD::SRA, MVT::i64, Custom);
}
if (TM.getSubtarget<PPCSubtarget>().hasAltivec()) {
addRegisterClass(MVT::v4f32, PPC::VRRCRegisterClass);
addRegisterClass(MVT::v4i32, PPC::VRRCRegisterClass);
}
setSetCCResultContents(ZeroOrOneSetCCResult);
setStackPointerRegisterToSaveRestore(PPC::R1);
computeRegisterProperties();
}
const char *PPCTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
default: return 0;
case PPCISD::FSEL: return "PPCISD::FSEL";
case PPCISD::FCFID: return "PPCISD::FCFID";
case PPCISD::FCTIDZ: return "PPCISD::FCTIDZ";
case PPCISD::FCTIWZ: return "PPCISD::FCTIWZ";
case PPCISD::VMADDFP: return "PPCISD::VMADDFP";
case PPCISD::VNMSUBFP: return "PPCISD::VNMSUBFP";
case PPCISD::Hi: return "PPCISD::Hi";
case PPCISD::Lo: return "PPCISD::Lo";
case PPCISD::GlobalBaseReg: return "PPCISD::GlobalBaseReg";
case PPCISD::SRL: return "PPCISD::SRL";
case PPCISD::SRA: return "PPCISD::SRA";
case PPCISD::SHL: return "PPCISD::SHL";
case PPCISD::RET_FLAG: return "PPCISD::RET_FLAG";
}
}
/// isFloatingPointZero - Return true if this is 0.0 or -0.0.
static bool isFloatingPointZero(SDOperand Op) {
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
return CFP->isExactlyValue(-0.0) || CFP->isExactlyValue(0.0);
else if (Op.getOpcode() == ISD::EXTLOAD || Op.getOpcode() == ISD::LOAD) {
// Maybe this has already been legalized into the constant pool?
if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Op.getOperand(1)))
if (ConstantFP *CFP = dyn_cast<ConstantFP>(CP->get()))
return CFP->isExactlyValue(-0.0) || CFP->isExactlyValue(0.0);
}
return false;
}
/// LowerOperation - Provide custom lowering hooks for some operations.
///
SDOperand PPCTargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
default: assert(0 && "Wasn't expecting to be able to lower this!");
case ISD::FP_TO_SINT: {
assert(MVT::isFloatingPoint(Op.getOperand(0).getValueType()));
SDOperand Src = Op.getOperand(0);
if (Src.getValueType() == MVT::f32)
Src = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Src);
SDOperand Tmp;
switch (Op.getValueType()) {
default: assert(0 && "Unhandled FP_TO_SINT type in custom expander!");
case MVT::i32:
Tmp = DAG.getNode(PPCISD::FCTIWZ, MVT::f64, Src);
break;
case MVT::i64:
Tmp = DAG.getNode(PPCISD::FCTIDZ, MVT::f64, Src);
break;
}
// Convert the FP value to an int value through memory.
SDOperand Bits = DAG.getNode(ISD::BIT_CONVERT, MVT::i64, Tmp);
if (Op.getValueType() == MVT::i32)
Bits = DAG.getNode(ISD::TRUNCATE, MVT::i32, Bits);
return Bits;
}
case ISD::SINT_TO_FP: {
assert(MVT::i64 == Op.getOperand(0).getValueType() &&
"Unhandled SINT_TO_FP type in custom expander!");
SDOperand Bits = DAG.getNode(ISD::BIT_CONVERT, MVT::f64, Op.getOperand(0));
SDOperand FP = DAG.getNode(PPCISD::FCFID, MVT::f64, Bits);
if (MVT::f32 == Op.getValueType())
FP = DAG.getNode(ISD::FP_ROUND, MVT::f32, FP);
return FP;
}
case ISD::SELECT_CC: {
// Turn FP only select_cc's into fsel instructions.
if (!MVT::isFloatingPoint(Op.getOperand(0).getValueType()) ||
!MVT::isFloatingPoint(Op.getOperand(2).getValueType()))
break;
ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
// Cannot handle SETEQ/SETNE.
if (CC == ISD::SETEQ || CC == ISD::SETNE) break;
MVT::ValueType ResVT = Op.getValueType();
MVT::ValueType CmpVT = Op.getOperand(0).getValueType();
SDOperand LHS = Op.getOperand(0), RHS = Op.getOperand(1);
SDOperand TV = Op.getOperand(2), FV = Op.getOperand(3);
// If the RHS of the comparison is a 0.0, we don't need to do the
// subtraction at all.
if (isFloatingPointZero(RHS))
switch (CC) {
default: break; // SETUO etc aren't handled by fsel.
case ISD::SETULT:
case ISD::SETLT:
std::swap(TV, FV); // fsel is natively setge, swap operands for setlt
case ISD::SETUGE:
case ISD::SETGE:
if (LHS.getValueType() == MVT::f32) // Comparison is always 64-bits
LHS = DAG.getNode(ISD::FP_EXTEND, MVT::f64, LHS);
return DAG.getNode(PPCISD::FSEL, ResVT, LHS, TV, FV);
case ISD::SETUGT:
case ISD::SETGT:
std::swap(TV, FV); // fsel is natively setge, swap operands for setlt
case ISD::SETULE:
case ISD::SETLE:
if (LHS.getValueType() == MVT::f32) // Comparison is always 64-bits
LHS = DAG.getNode(ISD::FP_EXTEND, MVT::f64, LHS);
return DAG.getNode(PPCISD::FSEL, ResVT,
DAG.getNode(ISD::FNEG, MVT::f64, LHS), TV, FV);
}
SDOperand Cmp;
switch (CC) {
default: break; // SETUO etc aren't handled by fsel.
case ISD::SETULT:
case ISD::SETLT:
Cmp = DAG.getNode(ISD::FSUB, CmpVT, LHS, RHS);
if (Cmp.getValueType() == MVT::f32) // Comparison is always 64-bits
Cmp = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Cmp);
return DAG.getNode(PPCISD::FSEL, ResVT, Cmp, FV, TV);
case ISD::SETUGE:
case ISD::SETGE:
Cmp = DAG.getNode(ISD::FSUB, CmpVT, LHS, RHS);
if (Cmp.getValueType() == MVT::f32) // Comparison is always 64-bits
Cmp = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Cmp);
return DAG.getNode(PPCISD::FSEL, ResVT, Cmp, TV, FV);
case ISD::SETUGT:
case ISD::SETGT:
Cmp = DAG.getNode(ISD::FSUB, CmpVT, RHS, LHS);
if (Cmp.getValueType() == MVT::f32) // Comparison is always 64-bits
Cmp = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Cmp);
return DAG.getNode(PPCISD::FSEL, ResVT, Cmp, FV, TV);
case ISD::SETULE:
case ISD::SETLE:
Cmp = DAG.getNode(ISD::FSUB, CmpVT, RHS, LHS);
if (Cmp.getValueType() == MVT::f32) // Comparison is always 64-bits
Cmp = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Cmp);
return DAG.getNode(PPCISD::FSEL, ResVT, Cmp, TV, FV);
}
break;
}
case ISD::SHL: {
assert(Op.getValueType() == MVT::i64 &&
Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SHL!");
// The generic code does a fine job expanding shift by a constant.
if (isa<ConstantSDNode>(Op.getOperand(1))) break;
// Otherwise, expand into a bunch of logical ops. Note that these ops
// depend on the PPC behavior for oversized shift amounts.
SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
DAG.getConstant(0, MVT::i32));
SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
DAG.getConstant(1, MVT::i32));
SDOperand Amt = Op.getOperand(1);
SDOperand Tmp1 = DAG.getNode(ISD::SUB, MVT::i32,
DAG.getConstant(32, MVT::i32), Amt);
SDOperand Tmp2 = DAG.getNode(PPCISD::SHL, MVT::i32, Hi, Amt);
SDOperand Tmp3 = DAG.getNode(PPCISD::SRL, MVT::i32, Lo, Tmp1);
SDOperand Tmp4 = DAG.getNode(ISD::OR , MVT::i32, Tmp2, Tmp3);
SDOperand Tmp5 = DAG.getNode(ISD::ADD, MVT::i32, Amt,
DAG.getConstant(-32U, MVT::i32));
SDOperand Tmp6 = DAG.getNode(PPCISD::SHL, MVT::i32, Lo, Tmp5);
SDOperand OutHi = DAG.getNode(ISD::OR, MVT::i32, Tmp4, Tmp6);
SDOperand OutLo = DAG.getNode(PPCISD::SHL, MVT::i32, Lo, Amt);
return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
}
case ISD::SRL: {
assert(Op.getValueType() == MVT::i64 &&
Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SHL!");
// The generic code does a fine job expanding shift by a constant.
if (isa<ConstantSDNode>(Op.getOperand(1))) break;
// Otherwise, expand into a bunch of logical ops. Note that these ops
// depend on the PPC behavior for oversized shift amounts.
SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
DAG.getConstant(0, MVT::i32));
SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
DAG.getConstant(1, MVT::i32));
SDOperand Amt = Op.getOperand(1);
SDOperand Tmp1 = DAG.getNode(ISD::SUB, MVT::i32,
DAG.getConstant(32, MVT::i32), Amt);
SDOperand Tmp2 = DAG.getNode(PPCISD::SRL, MVT::i32, Lo, Amt);
SDOperand Tmp3 = DAG.getNode(PPCISD::SHL, MVT::i32, Hi, Tmp1);
SDOperand Tmp4 = DAG.getNode(ISD::OR , MVT::i32, Tmp2, Tmp3);
SDOperand Tmp5 = DAG.getNode(ISD::ADD, MVT::i32, Amt,
DAG.getConstant(-32U, MVT::i32));
SDOperand Tmp6 = DAG.getNode(PPCISD::SRL, MVT::i32, Hi, Tmp5);
SDOperand OutLo = DAG.getNode(ISD::OR, MVT::i32, Tmp4, Tmp6);
SDOperand OutHi = DAG.getNode(PPCISD::SRL, MVT::i32, Hi, Amt);
return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
}
case ISD::SRA: {
assert(Op.getValueType() == MVT::i64 &&
Op.getOperand(1).getValueType() == MVT::i32 && "Unexpected SRA!");
// The generic code does a fine job expanding shift by a constant.
if (isa<ConstantSDNode>(Op.getOperand(1))) break;
// Otherwise, expand into a bunch of logical ops, followed by a select_cc.
SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
DAG.getConstant(0, MVT::i32));
SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op.getOperand(0),
DAG.getConstant(1, MVT::i32));
SDOperand Amt = Op.getOperand(1);
SDOperand Tmp1 = DAG.getNode(ISD::SUB, MVT::i32,
DAG.getConstant(32, MVT::i32), Amt);
SDOperand Tmp2 = DAG.getNode(PPCISD::SRL, MVT::i32, Lo, Amt);
SDOperand Tmp3 = DAG.getNode(PPCISD::SHL, MVT::i32, Hi, Tmp1);
SDOperand Tmp4 = DAG.getNode(ISD::OR , MVT::i32, Tmp2, Tmp3);
SDOperand Tmp5 = DAG.getNode(ISD::ADD, MVT::i32, Amt,
DAG.getConstant(-32U, MVT::i32));
SDOperand Tmp6 = DAG.getNode(PPCISD::SRA, MVT::i32, Hi, Tmp5);
SDOperand OutHi = DAG.getNode(PPCISD::SRA, MVT::i32, Hi, Amt);
SDOperand OutLo = DAG.getSelectCC(Tmp5, DAG.getConstant(0, MVT::i32),
Tmp4, Tmp6, ISD::SETLE);
return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, OutLo, OutHi);
}
case ISD::ConstantPool: {
Constant *C = cast<ConstantPoolSDNode>(Op)->get();
SDOperand CPI = DAG.getTargetConstantPool(C, MVT::i32);
SDOperand Zero = DAG.getConstant(0, MVT::i32);
if (PPCGenerateStaticCode) {
// Generate non-pic code that has direct accesses to the constant pool.
// The address of the global is just (hi(&g)+lo(&g)).
SDOperand Hi = DAG.getNode(PPCISD::Hi, MVT::i32, CPI, Zero);
SDOperand Lo = DAG.getNode(PPCISD::Lo, MVT::i32, CPI, Zero);
return DAG.getNode(ISD::ADD, MVT::i32, Hi, Lo);
}
// Only lower ConstantPool on Darwin.
if (!getTargetMachine().getSubtarget<PPCSubtarget>().isDarwin()) break;
SDOperand Hi = DAG.getNode(PPCISD::Hi, MVT::i32, CPI, Zero);
if (PICEnabled) {
// With PIC, the first instruction is actually "GR+hi(&G)".
Hi = DAG.getNode(ISD::ADD, MVT::i32,
DAG.getNode(PPCISD::GlobalBaseReg, MVT::i32), Hi);
}
SDOperand Lo = DAG.getNode(PPCISD::Lo, MVT::i32, CPI, Zero);
Lo = DAG.getNode(ISD::ADD, MVT::i32, Hi, Lo);
return Lo;
}
case ISD::GlobalAddress: {
GlobalAddressSDNode *GSDN = cast<GlobalAddressSDNode>(Op);
GlobalValue *GV = GSDN->getGlobal();
SDOperand GA = DAG.getTargetGlobalAddress(GV, MVT::i32, GSDN->getOffset());
SDOperand Zero = DAG.getConstant(0, MVT::i32);
if (PPCGenerateStaticCode) {
// Generate non-pic code that has direct accesses to globals.
// The address of the global is just (hi(&g)+lo(&g)).
SDOperand Hi = DAG.getNode(PPCISD::Hi, MVT::i32, GA, Zero);
SDOperand Lo = DAG.getNode(PPCISD::Lo, MVT::i32, GA, Zero);
return DAG.getNode(ISD::ADD, MVT::i32, Hi, Lo);
}
// Only lower GlobalAddress on Darwin.
if (!getTargetMachine().getSubtarget<PPCSubtarget>().isDarwin()) break;
SDOperand Hi = DAG.getNode(PPCISD::Hi, MVT::i32, GA, Zero);
if (PICEnabled) {
// With PIC, the first instruction is actually "GR+hi(&G)".
Hi = DAG.getNode(ISD::ADD, MVT::i32,
DAG.getNode(PPCISD::GlobalBaseReg, MVT::i32), Hi);
}
SDOperand Lo = DAG.getNode(PPCISD::Lo, MVT::i32, GA, Zero);
Lo = DAG.getNode(ISD::ADD, MVT::i32, Hi, Lo);
if (!GV->hasWeakLinkage() && !GV->hasLinkOnceLinkage() && !GV->isExternal())
return Lo;
// If the global is weak or external, we have to go through the lazy
// resolution stub.
return DAG.getLoad(MVT::i32, DAG.getEntryNode(), Lo, DAG.getSrcValue(0));
}
case ISD::VASTART: {
// vastart just stores the address of the VarArgsFrameIndex slot into the
// memory location argument.
// FIXME: Replace MVT::i32 with PointerTy
SDOperand FR = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32);
return DAG.getNode(ISD::STORE, MVT::Other, Op.getOperand(0), FR,
Op.getOperand(1), Op.getOperand(2));
}
case ISD::RET: {
SDOperand Copy;
switch(Op.getNumOperands()) {
default:
assert(0 && "Do not know how to return this many arguments!");
abort();
case 1:
return SDOperand(); // ret void is legal
case 2: {
MVT::ValueType ArgVT = Op.getOperand(1).getValueType();
unsigned ArgReg = MVT::isInteger(ArgVT) ? PPC::R3 : PPC::F1;
Copy = DAG.getCopyToReg(Op.getOperand(0), ArgReg, Op.getOperand(1),
SDOperand());
break;
}
case 3:
Copy = DAG.getCopyToReg(Op.getOperand(0), PPC::R3, Op.getOperand(2),
SDOperand());
Copy = DAG.getCopyToReg(Copy, PPC::R4, Op.getOperand(1),Copy.getValue(1));
break;
}
return DAG.getNode(PPCISD::RET_FLAG, MVT::Other, Copy, Copy.getValue(1));
}
}
return SDOperand();
}
std::vector<SDOperand>
PPCTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
//
// add beautiful description of PPC stack frame format, or at least some docs
//
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineBasicBlock& BB = MF.front();
SSARegMap *RegMap = MF.getSSARegMap();
std::vector<SDOperand> ArgValues;
unsigned ArgOffset = 24;
unsigned GPR_remaining = 8;
unsigned FPR_remaining = 13;
unsigned GPR_idx = 0, FPR_idx = 0;
static const unsigned GPR[] = {
PPC::R3, PPC::R4, PPC::R5, PPC::R6,
PPC::R7, PPC::R8, PPC::R9, PPC::R10,
};
static const unsigned FPR[] = {
PPC::F1, PPC::F2, PPC::F3, PPC::F4, PPC::F5, PPC::F6, PPC::F7,
PPC::F8, PPC::F9, PPC::F10, PPC::F11, PPC::F12, PPC::F13
};
// Add DAG nodes to load the arguments... On entry to a function on PPC,
// the arguments start at offset 24, although they are likely to be passed
// in registers.
for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
SDOperand newroot, argt;
unsigned ObjSize;
bool needsLoad = false;
bool ArgLive = !I->use_empty();
MVT::ValueType ObjectVT = getValueType(I->getType());
switch (ObjectVT) {
default: assert(0 && "Unhandled argument type!");
case MVT::i1:
case MVT::i8:
case MVT::i16:
case MVT::i32:
ObjSize = 4;
if (!ArgLive) break;
if (GPR_remaining > 0) {
unsigned VReg = RegMap->createVirtualRegister(&PPC::GPRCRegClass);
MF.addLiveIn(GPR[GPR_idx], VReg);
argt = newroot = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32);
if (ObjectVT != MVT::i32) {
unsigned AssertOp = I->getType()->isSigned() ? ISD::AssertSext
: ISD::AssertZext;
argt = DAG.getNode(AssertOp, MVT::i32, argt,
DAG.getValueType(ObjectVT));
argt = DAG.getNode(ISD::TRUNCATE, ObjectVT, argt);
}
} else {
needsLoad = true;
}
break;
case MVT::i64:
ObjSize = 8;
if (!ArgLive) break;
if (GPR_remaining > 0) {
SDOperand argHi, argLo;
unsigned VReg = RegMap->createVirtualRegister(&PPC::GPRCRegClass);
MF.addLiveIn(GPR[GPR_idx], VReg);
argHi = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32);
// If we have two or more remaining argument registers, then both halves
// of the i64 can be sourced from there. Otherwise, the lower half will
// have to come off the stack. This can happen when an i64 is preceded
// by 28 bytes of arguments.
if (GPR_remaining > 1) {
unsigned VReg = RegMap->createVirtualRegister(&PPC::GPRCRegClass);
MF.addLiveIn(GPR[GPR_idx+1], VReg);
argLo = DAG.getCopyFromReg(argHi, VReg, MVT::i32);
} else {
int FI = MFI->CreateFixedObject(4, ArgOffset+4);
SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
argLo = DAG.getLoad(MVT::i32, DAG.getEntryNode(), FIN,
DAG.getSrcValue(NULL));
}
// Build the outgoing arg thingy
argt = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, argLo, argHi);
newroot = argLo;
} else {
needsLoad = true;
}
break;
case MVT::f32:
case MVT::f64:
ObjSize = (ObjectVT == MVT::f64) ? 8 : 4;
if (!ArgLive) {
if (FPR_remaining > 0) {
--FPR_remaining;
++FPR_idx;
}
break;
}
if (FPR_remaining > 0) {
unsigned VReg;
if (ObjectVT == MVT::f32)
VReg = RegMap->createVirtualRegister(&PPC::F4RCRegClass);
else
VReg = RegMap->createVirtualRegister(&PPC::F8RCRegClass);
MF.addLiveIn(FPR[FPR_idx], VReg);
argt = newroot = DAG.getCopyFromReg(DAG.getRoot(), VReg, ObjectVT);
--FPR_remaining;
++FPR_idx;
} else {
needsLoad = true;
}
break;
}
// We need to load the argument to a virtual register if we determined above
// that we ran out of physical registers of the appropriate type
if (needsLoad) {
unsigned SubregOffset = 0;
if (ObjectVT == MVT::i8 || ObjectVT == MVT::i1) SubregOffset = 3;
if (ObjectVT == MVT::i16) SubregOffset = 2;
int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
FIN = DAG.getNode(ISD::ADD, MVT::i32, FIN,
DAG.getConstant(SubregOffset, MVT::i32));
argt = newroot = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN,
DAG.getSrcValue(NULL));
}
// Every 4 bytes of argument space consumes one of the GPRs available for
// argument passing.
if (GPR_remaining > 0) {
unsigned delta = (GPR_remaining > 1 && ObjSize == 8) ? 2 : 1;
GPR_remaining -= delta;
GPR_idx += delta;
}
ArgOffset += ObjSize;
if (newroot.Val)
DAG.setRoot(newroot.getValue(1));
ArgValues.push_back(argt);
}
// If the function takes variable number of arguments, make a frame index for
// the start of the first vararg value... for expansion of llvm.va_start.
if (F.isVarArg()) {
VarArgsFrameIndex = MFI->CreateFixedObject(4, ArgOffset);
SDOperand FIN = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32);
// If this function is vararg, store any remaining integer argument regs
// to their spots on the stack so that they may be loaded by deferencing the
// result of va_next.
std::vector<SDOperand> MemOps;
for (; GPR_remaining > 0; --GPR_remaining, ++GPR_idx) {
unsigned VReg = RegMap->createVirtualRegister(&PPC::GPRCRegClass);
MF.addLiveIn(GPR[GPR_idx], VReg);
SDOperand Val = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32);
SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, Val.getValue(1),
Val, FIN, DAG.getSrcValue(NULL));
MemOps.push_back(Store);
// Increment the address by four for the next argument to store
SDOperand PtrOff = DAG.getConstant(4, getPointerTy());
FIN = DAG.getNode(ISD::ADD, MVT::i32, FIN, PtrOff);
}
if (!MemOps.empty()) {
MemOps.push_back(DAG.getRoot());
DAG.setRoot(DAG.getNode(ISD::TokenFactor, MVT::Other, MemOps));
}
}
// Finally, inform the code generator which regs we return values in.
switch (getValueType(F.getReturnType())) {
default: assert(0 && "Unknown type!");
case MVT::isVoid: break;
case MVT::i1:
case MVT::i8:
case MVT::i16:
case MVT::i32:
MF.addLiveOut(PPC::R3);
break;
case MVT::i64:
MF.addLiveOut(PPC::R3);
MF.addLiveOut(PPC::R4);
break;
case MVT::f32:
case MVT::f64:
MF.addLiveOut(PPC::F1);
break;
}
return ArgValues;
}
std::pair<SDOperand, SDOperand>
PPCTargetLowering::LowerCallTo(SDOperand Chain,
const Type *RetTy, bool isVarArg,
unsigned CallingConv, bool isTailCall,
SDOperand Callee, ArgListTy &Args,
SelectionDAG &DAG) {
// args_to_use will accumulate outgoing args for the ISD::CALL case in
// SelectExpr to use to put the arguments in the appropriate registers.
std::vector<SDOperand> args_to_use;
// Count how many bytes are to be pushed on the stack, including the linkage
// area, and parameter passing area.
unsigned NumBytes = 24;
if (Args.empty()) {
Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
DAG.getConstant(NumBytes, getPointerTy()));
} else {
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
switch (getValueType(Args[i].second)) {
default: assert(0 && "Unknown value type!");
case MVT::i1:
case MVT::i8:
case MVT::i16:
case MVT::i32:
case MVT::f32:
NumBytes += 4;
break;
case MVT::i64:
case MVT::f64:
NumBytes += 8;
break;
}
}
// Just to be safe, we'll always reserve the full 24 bytes of linkage area
// plus 32 bytes of argument space in case any called code gets funky on us.
// (Required by ABI to support var arg)
if (NumBytes < 56) NumBytes = 56;
// Adjust the stack pointer for the new arguments...
// These operations are automatically eliminated by the prolog/epilog pass
Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
DAG.getConstant(NumBytes, getPointerTy()));
// Set up a copy of the stack pointer for use loading and storing any
// arguments that may not fit in the registers available for argument
// passing.
SDOperand StackPtr = DAG.getRegister(PPC::R1, MVT::i32);
// Figure out which arguments are going to go in registers, and which in
// memory. Also, if this is a vararg function, floating point operations
// must be stored to our stack, and loaded into integer regs as well, if
// any integer regs are available for argument passing.
unsigned ArgOffset = 24;
unsigned GPR_remaining = 8;
unsigned FPR_remaining = 13;
std::vector<SDOperand> MemOps;
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
// PtrOff will be used to store the current argument to the stack if a
// register cannot be found for it.
SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
MVT::ValueType ArgVT = getValueType(Args[i].second);
switch (ArgVT) {
default: assert(0 && "Unexpected ValueType for argument!");
case MVT::i1:
case MVT::i8:
case MVT::i16:
// Promote the integer to 32 bits. If the input type is signed use a
// sign extend, otherwise use a zero extend.
if (Args[i].second->isSigned())
Args[i].first =DAG.getNode(ISD::SIGN_EXTEND, MVT::i32, Args[i].first);
else
Args[i].first =DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Args[i].first);
// FALL THROUGH
case MVT::i32:
if (GPR_remaining > 0) {
args_to_use.push_back(Args[i].first);
--GPR_remaining;
} else {
MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
Args[i].first, PtrOff,
DAG.getSrcValue(NULL)));
}
ArgOffset += 4;
break;
case MVT::i64:
// If we have one free GPR left, we can place the upper half of the i64
// in it, and store the other half to the stack. If we have two or more
// free GPRs, then we can pass both halves of the i64 in registers.
if (GPR_remaining > 0) {
SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32,
Args[i].first, DAG.getConstant(1, MVT::i32));
SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32,
Args[i].first, DAG.getConstant(0, MVT::i32));
args_to_use.push_back(Hi);
--GPR_remaining;
if (GPR_remaining > 0) {
args_to_use.push_back(Lo);
--GPR_remaining;
} else {
SDOperand ConstFour = DAG.getConstant(4, getPointerTy());
PtrOff = DAG.getNode(ISD::ADD, MVT::i32, PtrOff, ConstFour);
MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
Lo, PtrOff, DAG.getSrcValue(NULL)));
}
} else {
MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
Args[i].first, PtrOff,
DAG.getSrcValue(NULL)));
}
ArgOffset += 8;
break;
case MVT::f32:
case MVT::f64:
if (FPR_remaining > 0) {
args_to_use.push_back(Args[i].first);
--FPR_remaining;
if (isVarArg) {
SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, Chain,
Args[i].first, PtrOff,
DAG.getSrcValue(NULL));
MemOps.push_back(Store);
// Float varargs are always shadowed in available integer registers
if (GPR_remaining > 0) {
SDOperand Load = DAG.getLoad(MVT::i32, Store, PtrOff,
DAG.getSrcValue(NULL));
MemOps.push_back(Load.getValue(1));
args_to_use.push_back(Load);
--GPR_remaining;
}
if (GPR_remaining > 0 && MVT::f64 == ArgVT) {
SDOperand ConstFour = DAG.getConstant(4, getPointerTy());
PtrOff = DAG.getNode(ISD::ADD, MVT::i32, PtrOff, ConstFour);
SDOperand Load = DAG.getLoad(MVT::i32, Store, PtrOff,
DAG.getSrcValue(NULL));
MemOps.push_back(Load.getValue(1));
args_to_use.push_back(Load);
--GPR_remaining;
}
} else {
// If we have any FPRs remaining, we may also have GPRs remaining.
// Args passed in FPRs consume either 1 (f32) or 2 (f64) available
// GPRs.
if (GPR_remaining > 0) {
args_to_use.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
--GPR_remaining;
}
if (GPR_remaining > 0 && MVT::f64 == ArgVT) {
args_to_use.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
--GPR_remaining;
}
}
} else {
MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
Args[i].first, PtrOff,
DAG.getSrcValue(NULL)));
}
ArgOffset += (ArgVT == MVT::f32) ? 4 : 8;
break;
}
}
if (!MemOps.empty())
Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, MemOps);
}
std::vector<MVT::ValueType> RetVals;
MVT::ValueType RetTyVT = getValueType(RetTy);
MVT::ValueType ActualRetTyVT = RetTyVT;
if (RetTyVT >= MVT::i1 && RetTyVT <= MVT::i16)
ActualRetTyVT = MVT::i32; // Promote result to i32.
if (RetTyVT != MVT::isVoid)
RetVals.push_back(ActualRetTyVT);
RetVals.push_back(MVT::Other);
// If the callee is a GlobalAddress node (quite common, every direct call is)
// turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i32);
SDOperand TheCall = SDOperand(DAG.getCall(RetVals,
Chain, Callee, args_to_use), 0);
Chain = TheCall.getValue(RetTyVT != MVT::isVoid);
Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
DAG.getConstant(NumBytes, getPointerTy()));
SDOperand RetVal = TheCall;
// If the result is a small value, add a note so that we keep track of the
// information about whether it is sign or zero extended.
if (RetTyVT != ActualRetTyVT) {
RetVal = DAG.getNode(RetTy->isSigned() ? ISD::AssertSext : ISD::AssertZext,
MVT::i32, RetVal, DAG.getValueType(RetTyVT));
RetVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, RetVal);
}
return std::make_pair(RetVal, Chain);
}
MachineBasicBlock *
PPCTargetLowering::InsertAtEndOfBasicBlock(MachineInstr *MI,
MachineBasicBlock *BB) {
assert((MI->getOpcode() == PPC::SELECT_CC_Int ||
MI->getOpcode() == PPC::SELECT_CC_F4 ||
MI->getOpcode() == PPC::SELECT_CC_F8) &&
"Unexpected instr type to insert");
// To "insert" a SELECT_CC instruction, we actually have to insert the diamond
// control-flow pattern. The incoming instruction knows the destination vreg
// to set, the condition code register to branch on, the true/false values to
// select between, and a branch opcode to use.
const BasicBlock *LLVM_BB = BB->getBasicBlock();
ilist<MachineBasicBlock>::iterator It = BB;
++It;
// thisMBB:
// ...
// TrueVal = ...
// cmpTY ccX, r1, r2
// bCC copy1MBB
// fallthrough --> copy0MBB
MachineBasicBlock *thisMBB = BB;
MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB);
MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB);
BuildMI(BB, MI->getOperand(4).getImmedValue(), 2)
.addReg(MI->getOperand(1).getReg()).addMBB(sinkMBB);
MachineFunction *F = BB->getParent();
F->getBasicBlockList().insert(It, copy0MBB);
F->getBasicBlockList().insert(It, sinkMBB);
// Update machine-CFG edges
BB->addSuccessor(copy0MBB);
BB->addSuccessor(sinkMBB);
// copy0MBB:
// %FalseValue = ...
// # fallthrough to sinkMBB
BB = copy0MBB;
// Update machine-CFG edges
BB->addSuccessor(sinkMBB);
// sinkMBB:
// %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
// ...
BB = sinkMBB;
BuildMI(BB, PPC::PHI, 4, MI->getOperand(0).getReg())
.addReg(MI->getOperand(3).getReg()).addMBB(copy0MBB)
.addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);
delete MI; // The pseudo instruction is gone now.
return BB;
}
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