mirror of
https://github.com/c64scene-ar/llvm-6502.git
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763d89343b
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55387 91177308-0d34-0410-b5e6-96231b3b80d8
496 lines
17 KiB
C++
496 lines
17 KiB
C++
///===-- FastISel.cpp - Implementation of the FastISel 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 file contains the implementation of the FastISel class.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Instructions.h"
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#include "llvm/CodeGen/FastISel.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Target/TargetInstrInfo.h"
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#include "llvm/Target/TargetLowering.h"
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#include "llvm/Target/TargetMachine.h"
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using namespace llvm;
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/// SelectBinaryOp - Select and emit code for a binary operator instruction,
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/// which has an opcode which directly corresponds to the given ISD opcode.
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///
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bool FastISel::SelectBinaryOp(Instruction *I, ISD::NodeType ISDOpcode,
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DenseMap<const Value*, unsigned> &ValueMap) {
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MVT VT = MVT::getMVT(I->getType(), /*HandleUnknown=*/true);
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if (VT == MVT::Other || !VT.isSimple())
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// Unhandled type. Halt "fast" selection and bail.
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return false;
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// We only handle legal types. For example, on x86-32 the instruction
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// selector contains all of the 64-bit instructions from x86-64,
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// under the assumption that i64 won't be used if the target doesn't
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// support it.
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if (!TLI.isTypeLegal(VT))
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return false;
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unsigned Op0 = ValueMap[I->getOperand(0)];
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if (Op0 == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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// Check if the second operand is a constant and handle it appropriately.
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if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
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unsigned ResultReg = FastEmit_ri_(VT.getSimpleVT(), ISDOpcode, Op0,
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CI->getZExtValue(), VT.getSimpleVT());
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if (ResultReg == 0)
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// Target-specific code wasn't able to find a machine opcode for
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// the given ISD opcode and type. Halt "fast" selection and bail.
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return false;
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// We successfully emitted code for the given LLVM Instruction.
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ValueMap[I] = ResultReg;
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return true;
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}
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unsigned Op1 = ValueMap[I->getOperand(1)];
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if (Op1 == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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unsigned ResultReg = FastEmit_rr(VT.getSimpleVT(), VT.getSimpleVT(),
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ISDOpcode, Op0, Op1);
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if (ResultReg == 0)
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// Target-specific code wasn't able to find a machine opcode for
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// the given ISD opcode and type. Halt "fast" selection and bail.
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return false;
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// We successfully emitted code for the given LLVM Instruction.
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ValueMap[I] = ResultReg;
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return true;
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}
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bool FastISel::SelectGetElementPtr(Instruction *I,
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DenseMap<const Value*, unsigned> &ValueMap) {
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unsigned N = ValueMap[I->getOperand(0)];
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if (N == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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const Type *Ty = I->getOperand(0)->getType();
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MVT::SimpleValueType VT = TLI.getPointerTy().getSimpleVT();
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for (GetElementPtrInst::op_iterator OI = I->op_begin()+1, E = I->op_end();
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OI != E; ++OI) {
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Value *Idx = *OI;
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if (const StructType *StTy = dyn_cast<StructType>(Ty)) {
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unsigned Field = cast<ConstantInt>(Idx)->getZExtValue();
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if (Field) {
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// N = N + Offset
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uint64_t Offs = TD.getStructLayout(StTy)->getElementOffset(Field);
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// FIXME: This can be optimized by combining the add with a
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// subsequent one.
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N = FastEmit_ri_(VT, ISD::ADD, N, Offs, VT);
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if (N == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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}
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Ty = StTy->getElementType(Field);
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} else {
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Ty = cast<SequentialType>(Ty)->getElementType();
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// If this is a constant subscript, handle it quickly.
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if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx)) {
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if (CI->getZExtValue() == 0) continue;
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uint64_t Offs =
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TD.getABITypeSize(Ty)*cast<ConstantInt>(CI)->getSExtValue();
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N = FastEmit_ri_(VT, ISD::ADD, N, Offs, VT);
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if (N == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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continue;
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}
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// N = N + Idx * ElementSize;
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uint64_t ElementSize = TD.getABITypeSize(Ty);
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unsigned IdxN = ValueMap[Idx];
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if (IdxN == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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// If the index is smaller or larger than intptr_t, truncate or extend
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// it.
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MVT IdxVT = MVT::getMVT(Idx->getType(), /*HandleUnknown=*/false);
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if (IdxVT.bitsLT(VT))
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IdxN = FastEmit_r(IdxVT.getSimpleVT(), VT, ISD::SIGN_EXTEND, IdxN);
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else if (IdxVT.bitsGT(VT))
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IdxN = FastEmit_r(IdxVT.getSimpleVT(), VT, ISD::TRUNCATE, IdxN);
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if (IdxN == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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if (ElementSize != 1) {
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IdxN = FastEmit_ri_(VT, ISD::MUL, IdxN, ElementSize, VT);
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if (IdxN == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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}
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N = FastEmit_rr(VT, VT, ISD::ADD, N, IdxN);
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if (N == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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}
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}
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// We successfully emitted code for the given LLVM Instruction.
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ValueMap[I] = N;
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return true;
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}
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bool FastISel::SelectBitCast(Instruction *I,
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DenseMap<const Value*, unsigned> &ValueMap) {
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// BitCast consists of either an immediate to register move
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// or a register to register move.
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if (ConstantInt* CI = dyn_cast<ConstantInt>(I->getOperand(0))) {
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if (I->getType()->isInteger()) {
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MVT VT = MVT::getMVT(I->getType(), /*HandleUnknown=*/false);
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unsigned result = FastEmit_i(VT.getSimpleVT(), VT.getSimpleVT(),
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ISD::Constant,
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CI->getZExtValue());
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if (!result)
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return false;
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ValueMap[I] = result;
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return true;
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}
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// TODO: Support vector and fp constants.
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return false;
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}
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if (!isa<Constant>(I->getOperand(0))) {
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// Bitcasts of non-constant values become reg-reg copies.
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MVT SrcVT = MVT::getMVT(I->getOperand(0)->getType());
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MVT DstVT = MVT::getMVT(I->getType());
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if (SrcVT == MVT::Other || !SrcVT.isSimple() ||
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DstVT == MVT::Other || !DstVT.isSimple() ||
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!TLI.isTypeLegal(SrcVT) || !TLI.isTypeLegal(DstVT))
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// Unhandled type. Halt "fast" selection and bail.
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return false;
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unsigned Op0 = ValueMap[I->getOperand(0)];
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if (Op0 == 0)
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// Unhandled operand. Halt "fast" selection and bail.
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return false;
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// First, try to perform the bitcast by inserting a reg-reg copy.
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unsigned ResultReg = 0;
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if (SrcVT.getSimpleVT() == DstVT.getSimpleVT()) {
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TargetRegisterClass* SrcClass = TLI.getRegClassFor(SrcVT);
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TargetRegisterClass* DstClass = TLI.getRegClassFor(DstVT);
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ResultReg = createResultReg(DstClass);
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bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
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Op0, DstClass, SrcClass);
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if (!InsertedCopy)
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ResultReg = 0;
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}
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// If the reg-reg copy failed, select a BIT_CONVERT opcode.
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if (!ResultReg)
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ResultReg = FastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(),
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ISD::BIT_CONVERT, Op0);
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if (!ResultReg)
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return false;
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ValueMap[I] = ResultReg;
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return true;
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}
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// TODO: Casting a non-integral constant?
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return false;
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}
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BasicBlock::iterator
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FastISel::SelectInstructions(BasicBlock::iterator Begin,
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BasicBlock::iterator End,
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DenseMap<const Value*, unsigned> &ValueMap,
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DenseMap<const BasicBlock*,
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MachineBasicBlock *> &MBBMap,
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MachineBasicBlock *mbb) {
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MBB = mbb;
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BasicBlock::iterator I = Begin;
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for (; I != End; ++I) {
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switch (I->getOpcode()) {
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case Instruction::Add: {
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ISD::NodeType Opc = I->getType()->isFPOrFPVector() ? ISD::FADD : ISD::ADD;
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if (!SelectBinaryOp(I, Opc, ValueMap)) return I; break;
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}
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case Instruction::Sub: {
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ISD::NodeType Opc = I->getType()->isFPOrFPVector() ? ISD::FSUB : ISD::SUB;
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if (!SelectBinaryOp(I, Opc, ValueMap)) return I; break;
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}
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case Instruction::Mul: {
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ISD::NodeType Opc = I->getType()->isFPOrFPVector() ? ISD::FMUL : ISD::MUL;
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if (!SelectBinaryOp(I, Opc, ValueMap)) return I; break;
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}
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case Instruction::SDiv:
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if (!SelectBinaryOp(I, ISD::SDIV, ValueMap)) return I; break;
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case Instruction::UDiv:
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if (!SelectBinaryOp(I, ISD::UDIV, ValueMap)) return I; break;
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case Instruction::FDiv:
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if (!SelectBinaryOp(I, ISD::FDIV, ValueMap)) return I; break;
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case Instruction::SRem:
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if (!SelectBinaryOp(I, ISD::SREM, ValueMap)) return I; break;
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case Instruction::URem:
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if (!SelectBinaryOp(I, ISD::UREM, ValueMap)) return I; break;
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case Instruction::FRem:
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if (!SelectBinaryOp(I, ISD::FREM, ValueMap)) return I; break;
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case Instruction::Shl:
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if (!SelectBinaryOp(I, ISD::SHL, ValueMap)) return I; break;
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case Instruction::LShr:
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if (!SelectBinaryOp(I, ISD::SRL, ValueMap)) return I; break;
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case Instruction::AShr:
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if (!SelectBinaryOp(I, ISD::SRA, ValueMap)) return I; break;
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case Instruction::And:
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if (!SelectBinaryOp(I, ISD::AND, ValueMap)) return I; break;
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case Instruction::Or:
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if (!SelectBinaryOp(I, ISD::OR, ValueMap)) return I; break;
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case Instruction::Xor:
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if (!SelectBinaryOp(I, ISD::XOR, ValueMap)) return I; break;
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case Instruction::GetElementPtr:
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if (!SelectGetElementPtr(I, ValueMap)) return I;
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break;
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case Instruction::Br: {
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BranchInst *BI = cast<BranchInst>(I);
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if (BI->isUnconditional()) {
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MachineFunction::iterator NextMBB =
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next(MachineFunction::iterator(MBB));
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BasicBlock *LLVMSucc = BI->getSuccessor(0);
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MachineBasicBlock *MSucc = MBBMap[LLVMSucc];
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if (NextMBB != MF.end() && MSucc == NextMBB) {
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// The unconditional fall-through case, which needs no instructions.
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} else {
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// The unconditional branch case.
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TII.InsertBranch(*MBB, MSucc, NULL, SmallVector<MachineOperand, 0>());
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}
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MBB->addSuccessor(MSucc);
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break;
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}
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// Conditional branches are not handed yet.
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// Halt "fast" selection and bail.
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return I;
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}
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case Instruction::PHI:
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// PHI nodes are already emitted.
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break;
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case Instruction::BitCast:
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if (!SelectBitCast(I, ValueMap)) return I;
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break;
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case Instruction::FPToSI:
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if (!isa<ConstantFP>(I->getOperand(0))) {
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MVT SrcVT = MVT::getMVT(I->getOperand(0)->getType());
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MVT DstVT = MVT::getMVT(I->getType());
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if (SrcVT == MVT::Other || !SrcVT.isSimple() ||
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DstVT == MVT::Other || !DstVT.isSimple() ||
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!TLI.isTypeLegal(SrcVT) || !TLI.isTypeLegal(DstVT))
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// Unhandled type. Halt "fast" selection and bail.
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return I;
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unsigned InputReg = ValueMap[I->getOperand(0)];
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if (!InputReg)
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// Unhandled operand. Halt "fast" selection and bail.
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return I;
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unsigned ResultReg = FastEmit_r(SrcVT.getSimpleVT(),
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DstVT.getSimpleVT(),
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ISD::FP_TO_SINT,
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InputReg);
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if (!ResultReg)
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return I;
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ValueMap[I] = ResultReg;
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break;
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} else
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// TODO: Materialize the FP constant and then convert,
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// or attempt constant folding.
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return I;
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case Instruction::SIToFP:
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if (!isa<ConstantInt>(I->getOperand(0))) {
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MVT SrcVT = MVT::getMVT(I->getOperand(0)->getType());
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MVT DstVT = MVT::getMVT(I->getType());
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if (SrcVT == MVT::Other || !SrcVT.isSimple() ||
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DstVT == MVT::Other || !DstVT.isSimple() ||
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!TLI.isTypeLegal(SrcVT) || !TLI.isTypeLegal(DstVT))
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// Unhandled type. Halt "fast" selection and bail.
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return I;
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unsigned InputReg = ValueMap[I->getOperand(0)];
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if (!InputReg)
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// Unhandled operan. Halt "fast" selection and bail.
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return I;
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unsigned ResultReg = FastEmit_r(SrcVT.getSimpleVT(),
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DstVT.getSimpleVT(),
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ISD::SINT_TO_FP,
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InputReg);
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if (!ResultReg)
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return I;
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ValueMap[I] = ResultReg;
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break;
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} else
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// TODO: Materialize constant and convert to FP.
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return I;
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default:
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// Unhandled instruction. Halt "fast" selection and bail.
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return I;
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}
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}
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return I;
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}
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FastISel::FastISel(MachineFunction &mf)
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: MF(mf),
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MRI(mf.getRegInfo()),
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TM(mf.getTarget()),
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TD(*TM.getTargetData()),
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TII(*TM.getInstrInfo()),
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TLI(*TM.getTargetLowering()) {
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}
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FastISel::~FastISel() {}
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unsigned FastISel::FastEmit_(MVT::SimpleValueType, MVT::SimpleValueType, ISD::NodeType) {
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return 0;
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}
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unsigned FastISel::FastEmit_r(MVT::SimpleValueType, MVT::SimpleValueType,
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ISD::NodeType, unsigned /*Op0*/) {
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return 0;
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}
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unsigned FastISel::FastEmit_rr(MVT::SimpleValueType, MVT::SimpleValueType,
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ISD::NodeType, unsigned /*Op0*/,
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unsigned /*Op0*/) {
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return 0;
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}
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unsigned FastISel::FastEmit_i(MVT::SimpleValueType, MVT::SimpleValueType,
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ISD::NodeType, uint64_t /*Imm*/) {
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return 0;
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}
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unsigned FastISel::FastEmit_ri(MVT::SimpleValueType, MVT::SimpleValueType,
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ISD::NodeType, unsigned /*Op0*/,
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uint64_t /*Imm*/) {
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return 0;
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}
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unsigned FastISel::FastEmit_rri(MVT::SimpleValueType, MVT::SimpleValueType,
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ISD::NodeType,
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unsigned /*Op0*/, unsigned /*Op1*/,
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uint64_t /*Imm*/) {
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return 0;
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}
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/// FastEmit_ri_ - This method is a wrapper of FastEmit_ri. It first tries
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/// to emit an instruction with an immediate operand using FastEmit_ri.
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/// If that fails, it materializes the immediate into a register and try
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/// FastEmit_rr instead.
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unsigned FastISel::FastEmit_ri_(MVT::SimpleValueType VT, ISD::NodeType Opcode,
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unsigned Op0, uint64_t Imm,
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MVT::SimpleValueType ImmType) {
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unsigned ResultReg = 0;
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// First check if immediate type is legal. If not, we can't use the ri form.
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if (TLI.getOperationAction(ISD::Constant, ImmType) == TargetLowering::Legal)
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ResultReg = FastEmit_ri(VT, VT, Opcode, Op0, Imm);
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if (ResultReg != 0)
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return ResultReg;
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unsigned MaterialReg = FastEmit_i(ImmType, ImmType, ISD::Constant, Imm);
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if (MaterialReg == 0)
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return 0;
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return FastEmit_rr(VT, VT, Opcode, Op0, MaterialReg);
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}
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unsigned FastISel::createResultReg(const TargetRegisterClass* RC) {
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return MRI.createVirtualRegister(RC);
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}
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unsigned FastISel::FastEmitInst_(unsigned MachineInstOpcode,
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const TargetRegisterClass* RC) {
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unsigned ResultReg = createResultReg(RC);
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const TargetInstrDesc &II = TII.get(MachineInstOpcode);
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BuildMI(MBB, II, ResultReg);
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return ResultReg;
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}
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unsigned FastISel::FastEmitInst_r(unsigned MachineInstOpcode,
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const TargetRegisterClass *RC,
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unsigned Op0) {
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unsigned ResultReg = createResultReg(RC);
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const TargetInstrDesc &II = TII.get(MachineInstOpcode);
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BuildMI(MBB, II, ResultReg).addReg(Op0);
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return ResultReg;
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}
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unsigned FastISel::FastEmitInst_rr(unsigned MachineInstOpcode,
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const TargetRegisterClass *RC,
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unsigned Op0, unsigned Op1) {
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unsigned ResultReg = createResultReg(RC);
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const TargetInstrDesc &II = TII.get(MachineInstOpcode);
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BuildMI(MBB, II, ResultReg).addReg(Op0).addReg(Op1);
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return ResultReg;
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}
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unsigned FastISel::FastEmitInst_ri(unsigned MachineInstOpcode,
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const TargetRegisterClass *RC,
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unsigned Op0, uint64_t Imm) {
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unsigned ResultReg = createResultReg(RC);
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const TargetInstrDesc &II = TII.get(MachineInstOpcode);
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BuildMI(MBB, II, ResultReg).addReg(Op0).addImm(Imm);
|
|
return ResultReg;
|
|
}
|
|
|
|
unsigned FastISel::FastEmitInst_rri(unsigned MachineInstOpcode,
|
|
const TargetRegisterClass *RC,
|
|
unsigned Op0, unsigned Op1, uint64_t Imm) {
|
|
unsigned ResultReg = createResultReg(RC);
|
|
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
|
|
|
|
BuildMI(MBB, II, ResultReg).addReg(Op0).addReg(Op1).addImm(Imm);
|
|
return ResultReg;
|
|
}
|
|
|
|
unsigned FastISel::FastEmitInst_i(unsigned MachineInstOpcode,
|
|
const TargetRegisterClass *RC,
|
|
uint64_t Imm) {
|
|
unsigned ResultReg = createResultReg(RC);
|
|
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
|
|
|
|
BuildMI(MBB, II, ResultReg).addImm(Imm);
|
|
return ResultReg;
|
|
}
|