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-rw-r--r--contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp21
1 files changed, 18 insertions, 3 deletions
diff --git a/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp b/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp
index 27c57d5..08bbe0c 100644
--- a/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp
+++ b/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp
@@ -218,6 +218,22 @@ bool LiveRangeEdit::foldAsLoad(LiveInterval *LI,
return true;
}
+bool LiveRangeEdit::useIsKill(const LiveInterval &LI,
+ const MachineOperand &MO) const {
+ const MachineInstr *MI = MO.getParent();
+ SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot();
+ if (LI.Query(Idx).isKill())
+ return true;
+ const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
+ unsigned SubReg = MO.getSubReg();
+ unsigned LaneMask = TRI.getSubRegIndexLaneMask(SubReg);
+ for (const LiveInterval::SubRange &S : LI.subranges()) {
+ if ((S.LaneMask & LaneMask) != 0 && S.Query(Idx).isKill())
+ return true;
+ }
+ return false;
+}
+
/// Find all live intervals that need to shrink, then remove the instruction.
void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) {
assert(MI->allDefsAreDead() && "Def isn't really dead");
@@ -266,9 +282,8 @@ void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) {
// unlikely to change anything. We typically don't want to shrink the
// PIC base register that has lots of uses everywhere.
// Always shrink COPY uses that probably come from live range splitting.
- if (MI->readsVirtualRegister(Reg) &&
- (MI->isCopy() || MOI->isDef() || MRI.hasOneNonDBGUse(Reg) ||
- LI.Query(Idx).isKill()))
+ if ((MI->readsVirtualRegister(Reg) && (MI->isCopy() || MOI->isDef())) ||
+ (MOI->readsReg() && (MRI.hasOneNonDBGUse(Reg) || useIsKill(LI, *MOI))))
ToShrink.insert(&LI);
// Remove defined value.
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