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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2009-11-30 22:55:54 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2009-11-30 22:55:54 +0000 |
| commit | 020d8d4c631a16fa797dc233655442c6cadd63cf (patch) | |
| tree | 895df9bffbe94532162ba80a0f4296d86f2814b1 | |
| parent | 132f3133ae348126993979867cf58de673016d4a (diff) | |
| download | bcm5719-llvm-020d8d4c631a16fa797dc233655442c6cadd63cf.tar.gz bcm5719-llvm-020d8d4c631a16fa797dc233655442c6cadd63cf.zip | |
New virtual registers created for spill intervals should inherit allocation hints from the original register.
This helps us avoid silly copies when rematting values that are copied to a physical register:
leaq _.str44(%rip), %rcx
movq %rcx, %rsi
call _strcmp
becomes:
leaq _.str44(%rip), %rsi
call _strcmp
The coalescer will not touch the movq because that would tie down the physical register.
llvm-svn: 90163
| -rw-r--r-- | llvm/lib/CodeGen/LiveIntervalAnalysis.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/2008-08-05-SpillerBug.ll | 2 |
2 files changed, 7 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp index 4412c1b020a..24adf364e71 100644 --- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -1095,6 +1095,12 @@ rewriteInstructionForSpills(const LiveInterval &li, const VNInfo *VNI, NewVReg = mri_->createVirtualRegister(rc); vrm.grow(); CreatedNewVReg = true; + + // The new virtual register should get the same allocation hints as the + // old one. + std::pair<unsigned, unsigned> Hint = mri_->getRegAllocationHint(Reg); + if (Hint.first || Hint.second) + mri_->setRegAllocationHint(NewVReg, Hint.first, Hint.second); } if (!TryFold) diff --git a/llvm/test/CodeGen/X86/2008-08-05-SpillerBug.ll b/llvm/test/CodeGen/X86/2008-08-05-SpillerBug.ll index 1d166f48815..67e14ffae5e 100644 --- a/llvm/test/CodeGen/X86/2008-08-05-SpillerBug.ll +++ b/llvm/test/CodeGen/X86/2008-08-05-SpillerBug.ll @@ -1,4 +1,4 @@ -; RUN: llc < %s -mtriple=i386-apple-darwin -disable-fp-elim -stats |& grep asm-printer | grep 59 +; RUN: llc < %s -mtriple=i386-apple-darwin -disable-fp-elim -stats |& grep asm-printer | grep 58 ; PR2568 @g_3 = external global i16 ; <i16*> [#uses=1] |
