PeepholeOptimizer: Ignore dead implicit defs
Target-specific instructions may have uninteresting physreg clobbers,
for target-specific reasons. The peephole pass doesn't need to concern
itself with such defs, as long as they're implicit and marked as dead.
llvm-svn: 255182
diff --git a/llvm/lib/CodeGen/PeepholeOptimizer.cpp b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
index 0fabc40..f861edf 100644
--- a/llvm/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
@@ -1343,6 +1343,9 @@
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || MO.isDef())
continue;
+ // Ignore dead implicit defs.
+ if (MO.isImplicit() && MO.isDead())
+ continue;
unsigned Reg = MO.getReg();
if (!TargetRegisterInfo::isVirtualRegister(Reg))
continue;
@@ -1703,6 +1706,9 @@
const MachineOperand &MO = Def->getOperand(OpIdx);
if (!MO.isReg() || !MO.getReg())
continue;
+ // Ignore dead implicit defs.
+ if (MO.isImplicit() && MO.isDead())
+ continue;
assert(!MO.isDef() && "We should have skipped all the definitions by now");
if (SrcIdx != EndOpIdx)
// Multiple sources?