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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-06-23 02:23:00 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-06-23 02:23:00 +0000 |
| commit | 7806c0778f22552ebe6711f3dc43887dc6097bfc (patch) | |
| tree | 2eb6e70baa395b80e298fba8b94c4e131b73e3c2 /lib/CodeGen/LiveVariables.cpp | |
| parent | ce0a5cda8aa547d5219da70a68bef40d5ed8392c (diff) | |
| download | llvm-7806c0778f22552ebe6711f3dc43887dc6097bfc.tar.gz llvm-7806c0778f22552ebe6711f3dc43887dc6097bfc.tar.bz2 llvm-7806c0778f22552ebe6711f3dc43887dc6097bfc.tar.xz | |
Teach LiveVariables to handle <undef> operands.
It's simple: Don't treat <undef> operands as uses, and don't assume a
virtual register has a defining instruction unless a real use has been
seen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159061 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/LiveVariables.cpp')
| -rw-r--r-- | lib/CodeGen/LiveVariables.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index acf986ca61..348ed3a0f9 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -573,7 +573,8 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) { unsigned MOReg = MO.getReg(); if (MO.isUse()) { MO.setIsKill(false); - UseRegs.push_back(MOReg); + if (MO.readsReg()) + UseRegs.push_back(MOReg); } else /*MO.isDef()*/ { MO.setIsDead(false); DefRegs.push_back(MOReg); @@ -729,8 +730,9 @@ void LiveVariables::analyzePHINodes(const MachineFunction& Fn) { for (MachineBasicBlock::const_iterator BBI = I->begin(), BBE = I->end(); BBI != BBE && BBI->isPHI(); ++BBI) for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2) - PHIVarInfo[BBI->getOperand(i + 1).getMBB()->getNumber()] - .push_back(BBI->getOperand(i).getReg()); + if (BBI->getOperand(i).readsReg()) + PHIVarInfo[BBI->getOperand(i + 1).getMBB()->getNumber()] + .push_back(BBI->getOperand(i).getReg()); } bool LiveVariables::VarInfo::isLiveIn(const MachineBasicBlock &MBB, |