From 31b9c44cc13bb686010cf6bfbeef8745c39939b9 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Tue, 11 May 2010 00:20:03 +0000 Subject: [PATCH] It's not safe eliminate copies where src and dst have different sub-register indices. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103450 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/ProcessImplicitDefs.cpp | 4 ++-- lib/CodeGen/RegAllocFast.cpp | 3 ++- lib/CodeGen/SimpleRegisterCoalescing.cpp | 12 +++++++----- lib/CodeGen/VirtRegRewriter.cpp | 6 ++++-- 4 files changed, 15 insertions(+), 10 deletions(-) diff --git a/lib/CodeGen/ProcessImplicitDefs.cpp b/lib/CodeGen/ProcessImplicitDefs.cpp index 75875d2835b..62f525fa1d9 100644 --- a/lib/CodeGen/ProcessImplicitDefs.cpp +++ b/lib/CodeGen/ProcessImplicitDefs.cpp @@ -46,7 +46,7 @@ bool ProcessImplicitDefs::CanTurnIntoImplicitDef(MachineInstr *MI, const TargetInstrInfo *tii_) { unsigned SrcReg, DstReg, SrcSubReg, DstSubReg; if (tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg) && - Reg == SrcReg) + Reg == SrcReg && SrcSubReg == 0 && DstSubReg == 0) return true; if (OpIdx == 2 && MI->isSubregToReg()) @@ -220,7 +220,7 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { // Turn a copy use into an implicit_def. unsigned SrcReg, DstReg, SrcSubReg, DstSubReg; if (tii_->isMoveInstr(*RMI, SrcReg, DstReg, SrcSubReg, DstSubReg) && - Reg == SrcReg) { + Reg == SrcReg && SrcSubReg == 0 && DstSubReg == 0) { RMI->setDesc(tii_->get(TargetOpcode::IMPLICIT_DEF)); bool isKill = false; diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp index 7eafbc84756..ab5e1032e15 100644 --- a/lib/CodeGen/RegAllocFast.cpp +++ b/lib/CodeGen/RegAllocFast.cpp @@ -583,7 +583,8 @@ void RAFast::AllocateBasicBlock(MachineBasicBlock &MBB) { unsigned SrcCopyPhysReg = 0U; bool isCopy = TII->isMoveInstr(*MI, SrcCopyReg, DstCopyReg, SrcCopySubReg, DstCopySubReg); - if (isCopy && TargetRegisterInfo::isVirtualRegister(SrcCopyReg)) + if (isCopy && SrcCopySubReg == 0 && DstCopySubReg == 0 && + TargetRegisterInfo::isVirtualRegister(SrcCopyReg)) SrcCopyPhysReg = getVirt2PhysRegMapSlot(SrcCopyReg); // Loop over the implicit uses, making sure they don't get reallocated. diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index 6b0b2d15819..7e13bf72240 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -460,7 +460,7 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA, unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) continue; - if (DstReg == IntB.reg) { + if (DstReg == IntB.reg && DstSubIdx == 0) { // This copy will become a noop. If it's defining a new val#, // remove that val# as well. However this live range is being // extended to the end of the existing live range defined by the copy. @@ -624,7 +624,7 @@ SimpleRegisterCoalescing::TrimLiveIntervalToLastUse(SlotIndex CopyIdx, LR->valno->addKill(LastUseIdx.getDefIndex()); unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; if (tii_->isMoveInstr(*LastUseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) && - DstReg == li.reg) { + DstReg == li.reg && DstSubIdx == 0) { // Last use is itself an identity code. int DeadIdx = LastUseMI->findRegisterDefOperandIdx(li.reg, false, tri_); LastUseMI->getOperand(DeadIdx).setIsDead(); @@ -810,6 +810,8 @@ SimpleRegisterCoalescing::UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg, unsigned CopySrcReg, CopyDstReg, CopySrcSubIdx, CopyDstSubIdx; if (tii_->isMoveInstr(*UseMI, CopySrcReg, CopyDstReg, CopySrcSubIdx, CopyDstSubIdx) && + CopySrcSubIdx == 0 && + CopyDstSubIdx == 0 && CopySrcReg != CopyDstReg && CopySrcReg == SrcReg && CopyDstReg != UseDstReg) { // If the use is a copy and it won't be coalesced away, and its source @@ -2637,7 +2639,7 @@ SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start, MachineInstr *UseMI = Use.getParent(); unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; if (tii_->isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) && - SrcReg == DstReg) + SrcReg == DstReg && SrcSubIdx == DstSubIdx) // Ignore identity copies. continue; SlotIndex Idx = li_->getInstructionIndex(UseMI); @@ -2666,7 +2668,7 @@ SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start, // Ignore identity copies. unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; if (!(tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) && - SrcReg == DstReg)) + SrcReg == DstReg && SrcSubIdx == DstSubIdx)) for (unsigned i = 0, NumOps = MI->getNumOperands(); i != NumOps; ++i) { MachineOperand &Use = MI->getOperand(i); if (Use.isReg() && Use.isUse() && Use.getReg() && @@ -2797,7 +2799,7 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) { // If the move will be an identity move delete it bool isMove= tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx); - if (isMove && SrcReg == DstReg) { + if (isMove && SrcReg == DstReg && SrcSubIdx == DstSubIdx) { if (li_->hasInterval(SrcReg)) { LiveInterval &RegInt = li_->getInterval(SrcReg); // If def of this move instruction is dead, remove its live range diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp index 9b46273455a..9c3248067af 100644 --- a/lib/CodeGen/VirtRegRewriter.cpp +++ b/lib/CodeGen/VirtRegRewriter.cpp @@ -2425,7 +2425,8 @@ LocalRewriter::RewriteMBB(LiveIntervals *LIs, // eliminate this or else the undef marker is lost and it will // confuses the scavenger. This is extremely rare. unsigned Src, Dst, SrcSR, DstSR; - if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && Src == Dst && + if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && + Src == Dst && SrcSR == DstSR && !MI.findRegisterUseOperand(Src)->isUndef()) { ++NumDCE; DEBUG(dbgs() << "Removing now-noop copy: " << MI); @@ -2514,7 +2515,8 @@ LocalRewriter::RewriteMBB(LiveIntervals *LIs, // instruction before considering the dest reg to be changed. { unsigned Src, Dst, SrcSR, DstSR; - if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && Src == Dst) { + if (TII->isMoveInstr(MI, Src, Dst, SrcSR, DstSR) && + Src == Dst && SrcSR == DstSR) { ++NumDCE; DEBUG(dbgs() << "Removing now-noop copy: " << MI); InvalidateKills(MI, TRI, RegKills, KillOps);