From d01fb9e212d989ff14e84a332c5b18f8a23d4b35 Mon Sep 17 00:00:00 2001 From: Tim Northover Date: Thu, 30 May 2013 12:30:50 +0000 Subject: [PATCH] Fix rematerialization into physical registers. r182872 introduced a bug in how the register-coalescer's rematerialization handled defining a physical register. It relied on the output of the coalescer's setRegisters method to determine whether the replacement instruction needed an implicit-def. However, this value isn't necessarily the same as the CopyMI's actual destination register which is what the rest of the basic-block expects us to be defining. The commit changes the rematerializer to use the actual register attached to CopyMI in its decision. This will be tested soon by an X86 patch which moves everything to using MOV32r0 instead of other sizes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182925 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/RegisterCoalescer.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp index f0e62412ba7..82043c2bf7d 100644 --- a/lib/CodeGen/RegisterCoalescer.cpp +++ b/lib/CodeGen/RegisterCoalescer.cpp @@ -762,6 +762,7 @@ bool RegisterCoalescer::reMaterializeTrivialDef(CoalescerPair &CP, return false; // Only support subregister destinations when the def is read-undef. MachineOperand &DstOperand = CopyMI->getOperand(0); + unsigned CopyDstReg = DstOperand.getReg(); if (DstOperand.getSubReg() && !DstOperand.isUndef()) return false; @@ -837,12 +838,12 @@ bool RegisterCoalescer::reMaterializeTrivialDef(CoalescerPair &CP, NewMI->getOperand(0).setSubReg( TRI->composeSubRegIndices(SrcIdx, DefMI->getOperand(0).getSubReg())); } - } else if (NewMI->getOperand(0).getReg() != DstReg) { + } else if (NewMI->getOperand(0).getReg() != CopyDstReg) { // The New instruction may be defining a sub-register of what's actually // been asked for. If so it must implicitly define the whole thing. assert(TargetRegisterInfo::isPhysicalRegister(DstReg) && "Only expect virtual or physical registers in remat"); - NewMI->addOperand(MachineOperand::CreateReg(DstReg, + NewMI->addOperand(MachineOperand::CreateReg(CopyDstReg, true /*IsDef*/, true /*IsImp*/, false /*IsKill*/)); -- 2.34.1