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| author | Hans Wennborg <hans@hanshq.net> | 2016-05-18 16:10:17 +0000 |
|---|---|---|
| committer | Hans Wennborg <hans@hanshq.net> | 2016-05-18 16:10:17 +0000 |
| commit | 8eb336c14e4c033a3f81a3a43fe397f0879a2e68 (patch) | |
| tree | e85fba6e6e6ed0c2528c0c565c6fea53085520d6 /llvm/lib/CodeGen/RegAllocFast.cpp | |
| parent | 9430b9113a54eafaa9bd7d7bb288c7a457d26404 (diff) | |
| download | bcm5719-llvm-8eb336c14e4c033a3f81a3a43fe397f0879a2e68.tar.gz bcm5719-llvm-8eb336c14e4c033a3f81a3a43fe397f0879a2e68.zip | |
Re-commit r269828 "X86: Avoid using _chkstk when lowering WIN_ALLOCA instructions"
with an additional fix to make RegAllocFast ignore undef physreg uses. It would
previously get confused about the "push %eax" instruction's use of eax. That
method for adjusting the stack pointer is used in X86FrameLowering::emitSPUpdate
as well, but since that runs after register-allocation, we didn't run into the
RegAllocFast issue before.
llvm-svn: 269949
Diffstat (limited to 'llvm/lib/CodeGen/RegAllocFast.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/RegAllocFast.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp index d18ecf91ea4..83b59bae838 100644 --- a/llvm/lib/CodeGen/RegAllocFast.cpp +++ b/llvm/lib/CodeGen/RegAllocFast.cpp @@ -349,6 +349,11 @@ void RAFast::usePhysReg(MachineOperand &MO) { unsigned PhysReg = MO.getReg(); assert(TargetRegisterInfo::isPhysicalRegister(PhysReg) && "Bad usePhysReg operand"); + + // Ignore undef uses. + if (MO.isUndef()) + return; + markRegUsedInInstr(PhysReg); switch (PhysRegState[PhysReg]) { case regDisabled: |
