diff options
| author | Alexander Kornienko <alexfh@google.com> | 2012-11-30 17:06:02 +0000 |
|---|---|---|
| committer | Alexander Kornienko <alexfh@google.com> | 2012-11-30 17:06:02 +0000 |
| commit | ccaf20cc53a3dc353f4786b1ebf4ebb3f81d4746 (patch) | |
| tree | 526aace1ee6cd0126263e06eed2d23eae06d7d84 /lib/CodeGen/MachineBasicBlock.cpp | |
| parent | 26c41c96df38631aa2bce1ff87acb31871111f83 (diff) | |
| parent | 72a2c0622ab072030c9108badea50074d96bec6a (diff) | |
Updating branches/google/testing to r168474
git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/google/testing@169005 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/MachineBasicBlock.cpp')
| -rw-r--r-- | lib/CodeGen/MachineBasicBlock.cpp | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 18d021d521..4406c89aba 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -982,7 +982,6 @@ MachineBasicBlock::LivenessQueryResult MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, unsigned Reg, MachineInstr *MI, unsigned Neighborhood) { - unsigned N = Neighborhood; MachineBasicBlock *MBB = MI->getParent(); @@ -997,14 +996,18 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, MachineOperandIteratorBase::PhysRegInfo Analysis = MIOperands(I).analyzePhysReg(Reg, TRI); - if (Analysis.Kills) + if (Analysis.Defines) + // Outputs happen after inputs so they take precedence if both are + // present. + return Analysis.DefinesDead ? LQR_Dead : LQR_Live; + + if (Analysis.Kills || Analysis.Clobbers) // Register killed, so isn't live. return LQR_Dead; - else if (Analysis.DefinesOverlap || Analysis.ReadsOverlap) + else if (Analysis.ReadsOverlap) // Defined or read without a previous kill - live. - return (Analysis.Defines || Analysis.Reads) ? - LQR_Live : LQR_OverlappingLive; + return Analysis.Reads ? LQR_Live : LQR_OverlappingLive; } while (I != MBB->begin() && --N > 0); } @@ -1036,7 +1039,7 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, return (Analysis.Reads) ? LQR_Live : LQR_OverlappingLive; - else if (Analysis.DefinesOverlap) + else if (Analysis.Clobbers || Analysis.Defines) // Defined (but not read) therefore cannot have been live. return LQR_Dead; } |