diff options
Diffstat (limited to 'lib/CodeGen/MachineLICM.cpp')
| -rw-r--r-- | lib/CodeGen/MachineLICM.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp index 52d5819f8dbcd..c7113f1fdc47a 100644 --- a/lib/CodeGen/MachineLICM.cpp +++ b/lib/CodeGen/MachineLICM.cpp @@ -895,8 +895,11 @@ bool MachineLICM::IsLoopInvariantInst(MachineInstr &I) { // If the physreg has no defs anywhere, it's just an ambient register // and we can freely move its uses. Alternatively, if it's allocatable, // it could get allocated to something with a def during allocation. - if (!MRI->isConstantPhysReg(Reg)) - return false; + // However, if the physreg is known to always be caller saved/restored + // then this use is safe to hoist. + if (!MRI->isConstantPhysReg(Reg) && + !(TRI->isCallerPreservedPhysReg(Reg, *I.getParent()->getParent()))) + return false; // Otherwise it's safe to move. continue; } else if (!MO.isDead()) { |