diff options
| author | Bob Wilson <bob.wilson@apple.com> | 2010-02-12 01:30:21 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2010-02-12 01:30:21 +0000 |
| commit | 0827e040e0071bdc59b26d6a8936459e1304f682 (patch) | |
| tree | d8d9684a14be1f90db7bb4e46528cf641140ec05 /llvm/lib/CodeGen/LLVMTargetMachine.cpp | |
| parent | d7e9212e2d33bfe528b6996c4e7f722dff808c76 (diff) | |
| download | bcm5719-llvm-0827e040e0071bdc59b26d6a8936459e1304f682.tar.gz bcm5719-llvm-0827e040e0071bdc59b26d6a8936459e1304f682.zip | |
Add a new pass on machine instructions to optimize away PHI cycles that
reduce down to a single value. InstCombine already does this transformation
but DAG legalization may introduce new opportunities. This has turned out to
be important for ARM where 64-bit values are split up during type legalization:
InstCombine is not able to remove the PHI cycles on the 64-bit values but
the separate 32-bit values can be optimized. I measured the compile time
impact of this (running llc on 176.gcc) and it was not significant.
llvm-svn: 95951
Diffstat (limited to 'llvm/lib/CodeGen/LLVMTargetMachine.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/LLVMTargetMachine.cpp | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/LLVMTargetMachine.cpp b/llvm/lib/CodeGen/LLVMTargetMachine.cpp index 40e015067f4..3c12afaacf6 100644 --- a/llvm/lib/CodeGen/LLVMTargetMachine.cpp +++ b/llvm/lib/CodeGen/LLVMTargetMachine.cpp @@ -299,6 +299,7 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, if (OptLevel != CodeGenOpt::None) { PM.add(createOptimizeExtsPass()); + PM.add(createOptimizePHIsPass()); if (!DisableMachineLICM) PM.add(createMachineLICMPass()); if (!DisableMachineSink) |
