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author | Evan Cheng <evan.cheng@apple.com> | 2010-04-08 20:02:37 +0000 |
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committer | Evan Cheng <evan.cheng@apple.com> | 2010-04-08 20:02:37 +0000 |
commit | a57fabe815ccf016eead526eb3ef475f116ab155 (patch) | |
tree | c5766e5dbbe4131e812a643263b6355ff962132e /lib | |
parent | b8db3c2c507cc115ed773209eae6cb8b89db1586 (diff) | |
download | llvm-a57fabe815ccf016eead526eb3ef475f116ab155.tar.gz llvm-a57fabe815ccf016eead526eb3ef475f116ab155.tar.bz2 llvm-a57fabe815ccf016eead526eb3ef475f116ab155.tar.xz |
Coalescer should not delete copy instructions whose defs are partially dead. e.g.
%RDI<def,dead> = MOV64rr %RAX<kill>, %EDI<imp-def>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100804 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/CodeGen/MachineInstr.cpp | 13 | ||||
-rw-r--r-- | lib/CodeGen/SimpleRegisterCoalescing.cpp | 2 |
2 files changed, 14 insertions, 1 deletions
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp index f2ba484e4f..9f03b5bac7 100644 --- a/lib/CodeGen/MachineInstr.cpp +++ b/lib/CodeGen/MachineInstr.cpp @@ -1125,6 +1125,19 @@ unsigned MachineInstr::isConstantValuePHI() const { return Reg; } +/// allDefsAreDead - Return true if all the defs of this instruction are dead. +/// +bool MachineInstr::allDefsAreDead() const { + for (unsigned i = 0, e = getNumOperands(); i < e; ++i) { + const MachineOperand &MO = getOperand(i); + if (!MO.isReg() || MO.isUse()) + continue; + if (!MO.isDead()) + return false; + } + return true; +} + void MachineInstr::dump() const { dbgs() << " " << *this; } diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index 15ca3740b8..1f9d726143 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -2744,7 +2744,7 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) { // delete them later. DoDelete = false; } - if (MI->registerDefIsDead(DstReg)) { + if (MI->allDefsAreDead()) { LiveInterval &li = li_->getInterval(DstReg); if (!ShortenDeadCopySrcLiveRange(li, MI)) ShortenDeadCopyLiveRange(li, MI); |