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| author | Chris Lattner <sabre@nondot.org> | 2004-02-13 23:36:47 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2004-02-13 23:36:47 +0000 |
| commit | 7b5f374a18a19729712e3a581b20dce8137305be (patch) | |
| tree | 2790f09c7ee4f6fdaf8c9ac5fb4c8867406935a8 | |
| parent | 23472a5a2a4542e98f056eaf39608f5839f191e2 (diff) | |
| download | bcm5719-llvm-7b5f374a18a19729712e3a581b20dce8137305be.tar.gz bcm5719-llvm-7b5f374a18a19729712e3a581b20dce8137305be.zip | |
There is no need to emit a shift if the size is constant, which is common
llvm-svn: 11420
| -rw-r--r-- | llvm/lib/Target/X86/InstSelectSimple.cpp | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/llvm/lib/Target/X86/InstSelectSimple.cpp b/llvm/lib/Target/X86/InstSelectSimple.cpp index 67849e2edbb..54aa1ad0d23 100644 --- a/llvm/lib/Target/X86/InstSelectSimple.cpp +++ b/llvm/lib/Target/X86/InstSelectSimple.cpp @@ -1198,21 +1198,29 @@ void ISel::visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI) { } // Turn the byte code into # iterations - unsigned ByteReg = getReg(CI.getOperand(3)); + unsigned ByteReg; unsigned CountReg; switch (Align & 3) { case 2: // WORD aligned - CountReg = makeAnotherReg(Type::IntTy); - BuildMI(BB, X86::SHRir32, 2, CountReg).addReg(ByteReg).addZImm(1); + if (ConstantInt *I = dyn_cast<ConstantInt>(CI.getOperand(3))) { + CountReg = getReg(ConstantUInt::get(Type::UIntTy, I->getRawValue()/2)); + } else { + CountReg = makeAnotherReg(Type::IntTy); + BuildMI(BB, X86::SHRir32, 2, CountReg).addReg(ByteReg).addZImm(1); + } break; case 0: // DWORD aligned - CountReg = makeAnotherReg(Type::IntTy); - BuildMI(BB, X86::SHRir32, 2, CountReg).addReg(ByteReg).addZImm(2); + if (ConstantInt *I = dyn_cast<ConstantInt>(CI.getOperand(3))) { + CountReg = getReg(ConstantUInt::get(Type::UIntTy, I->getRawValue()/4)); + } else { + CountReg = makeAnotherReg(Type::IntTy); + BuildMI(BB, X86::SHRir32, 2, CountReg).addReg(ByteReg).addZImm(2); + } break; case 1: // BYTE aligned case 3: // BYTE aligned - CountReg = ByteReg; + CountReg = getReg(CI.getOperand(3)); break; } @@ -1224,7 +1232,6 @@ void ISel::visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI) { BuildMI(BB, X86::MOVrr32, 1, X86::EDI).addReg(TmpReg1); BuildMI(BB, X86::MOVrr32, 1, X86::ESI).addReg(TmpReg2); - unsigned Bytes = getReg(CI.getOperand(3)); switch (Align & 3) { case 1: // BYTE aligned case 3: // BYTE aligned |
