diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index 139a905ec3..2323f5790a 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -992,8 +992,10 @@ X86InstrInfo::isReallyTriviallyReMaterializable(const MachineInstr *MI, /// a few instructions in each direction it assumes it's not safe. static bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB, MachineBasicBlock::iterator I) { + MachineBasicBlock::iterator E = MBB.end(); + // It's always safe to clobber EFLAGS at the end of a block. - if (I == MBB.end()) + if (I == E) return true; // For compile time consideration, if we are not able to determine the @@ -1017,20 +1019,28 @@ static bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB, // This instruction defines EFLAGS, no need to look any further. return true; ++Iter; + // Skip over DBG_VALUE. + while (Iter != E && Iter->isDebugValue()) + ++Iter; // If we make it to the end of the block, it's safe to clobber EFLAGS. - if (Iter == MBB.end()) + if (Iter == E) return true; } + MachineBasicBlock::iterator B = MBB.begin(); Iter = I; for (unsigned i = 0; i < 4; ++i) { // If we make it to the beginning of the block, it's safe to clobber // EFLAGS iff EFLAGS is not live-in. - if (Iter == MBB.begin()) + if (Iter == B) return !MBB.isLiveIn(X86::EFLAGS); --Iter; + // Skip over DBG_VALUE. + while (Iter != B && Iter->isDebugValue()) + --Iter; + bool SawKill = false; for (unsigned j = 0, e = Iter->getNumOperands(); j != e; ++j) { MachineOperand &MO = Iter->getOperand(j); |