Use MRI::isConstantPhysReg() to check remat feasibility.
Don't depend on LiveIntervals::hasInterval() to determine if a physreg
is reserved and constant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159013 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 434388b..261d860 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -82,11 +82,15 @@
UseIdx = UseIdx.getRegSlot(true);
for (unsigned i = 0, e = OrigMI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = OrigMI->getOperand(i);
- if (!MO.isReg() || !MO.getReg() || MO.isDef())
+ if (!MO.isReg() || !MO.getReg() || !MO.readsReg())
continue;
- // Reserved registers are OK.
- if (MO.isUndef() || !LIS.hasInterval(MO.getReg()))
- continue;
+
+ // We can't remat physreg uses, unless it is a constant.
+ if (TargetRegisterInfo::isPhysicalRegister(MO.getReg())) {
+ if (MRI.isConstantPhysReg(MO.getReg(), VRM->getMachineFunction()))
+ continue;
+ return false;
+ }
LiveInterval &li = LIS.getInterval(MO.getReg());
const VNInfo *OVNI = li.getVNInfoAt(OrigIdx);