diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp index 52ea87231cc..f54d879759f 100644 --- a/lib/CodeGen/TwoAddressInstructionPass.cpp +++ b/lib/CodeGen/TwoAddressInstructionPass.cpp @@ -1125,6 +1125,7 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { break; // The tied operands have been eliminated. } + bool IsEarlyClobber = false; bool RemovedKillFlag = false; bool AllUsesCopied = true; unsigned LastCopiedReg = 0; @@ -1132,7 +1133,11 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { for (unsigned tpi = 0, tpe = TiedPairs.size(); tpi != tpe; ++tpi) { unsigned SrcIdx = TiedPairs[tpi].first; unsigned DstIdx = TiedPairs[tpi].second; - unsigned regA = mi->getOperand(DstIdx).getReg(); + + const MachineOperand &DstMO = mi->getOperand(DstIdx); + unsigned regA = DstMO.getReg(); + IsEarlyClobber |= DstMO.isEarlyClobber(); + // Grab regB from the instruction because it may have changed if the // instruction was commuted. regB = mi->getOperand(SrcIdx).getReg(); @@ -1196,15 +1201,17 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { } if (AllUsesCopied) { - // Replace other (un-tied) uses of regB with LastCopiedReg. - for (unsigned i = 0, e = mi->getNumOperands(); i != e; ++i) { - MachineOperand &MO = mi->getOperand(i); - if (MO.isReg() && MO.getReg() == regB && MO.isUse()) { - if (MO.isKill()) { - MO.setIsKill(false); - RemovedKillFlag = true; + if (!IsEarlyClobber) { + // Replace other (un-tied) uses of regB with LastCopiedReg. + for (unsigned i = 0, e = mi->getNumOperands(); i != e; ++i) { + MachineOperand &MO = mi->getOperand(i); + if (MO.isReg() && MO.getReg() == regB && MO.isUse()) { + if (MO.isKill()) { + MO.setIsKill(false); + RemovedKillFlag = true; + } + MO.setReg(LastCopiedReg); } - MO.setReg(LastCopiedReg); } } diff --git a/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll b/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll new file mode 100644 index 00000000000..9e6d78e75dc --- /dev/null +++ b/test/CodeGen/Thumb2/2011-06-07-TwoAddrEarlyClobber.ll @@ -0,0 +1,36 @@ +; RUN: llc < %s | FileCheck %s +target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:32:64-v128:32:128-a0:0:32-n32" +target triple = "thumbv7-apple-darwin10" + +%struct.op = type { %struct.op*, %struct.op*, %struct.op* ()*, i32, i16, i16, i8, i8 } + +; CHECK: Perl_ck_sort +; CHECK: ldr +; CHECK: mov [[REGISTER:(r[0-9]+)|(lr)]] +; CHECK: str {{(r[0-9])|(lr)}}, {{\[}}[[REGISTER]]{{\]}}, #24 + +define void @Perl_ck_sort() nounwind optsize { +entry: + %tmp27 = load %struct.op** undef, align 4 + switch i16 undef, label %if.end151 [ + i16 178, label %if.then60 + i16 177, label %if.then60 + ] + +if.then60: ; preds = %if.then40 + br i1 undef, label %if.then67, label %if.end95 + +if.then67: ; preds = %if.then60 + %op_next71 = getelementptr inbounds %struct.op* %tmp27, i32 0, i32 0 + store %struct.op* %tmp27, %struct.op** %op_next71, align 4 + %0 = getelementptr inbounds %struct.op* %tmp27, i32 1, i32 0 + br label %if.end95 + +if.end95: ; preds = %if.else92, %if.then67 + %.pre-phi = phi %struct.op** [ undef, %if.then60 ], [ %0, %if.then67 ] + %tmp98 = load %struct.op** %.pre-phi, align 4 + br label %if.end151 + +if.end151: ; preds = %if.end100, %if.end, %entry + ret void +}