Fix thinko. Cmp can be the first instruction in a MBB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125552 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PeepholeOptimizer.cpp b/lib/CodeGen/PeepholeOptimizer.cpp
index 3474f75..5d7123c 100644
--- a/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/lib/CodeGen/PeepholeOptimizer.cpp
@@ -331,7 +331,8 @@
ImmDefRegs.clear();
ImmDefMIs.clear();
- MachineBasicBlock::iterator PMII = I->begin();
+ bool First = true;
+ MachineBasicBlock::iterator PMII;
for (MachineBasicBlock::iterator
MII = I->begin(), MIE = I->end(); MII != MIE; ) {
MachineInstr *MI = &*MII;
@@ -348,7 +349,7 @@
if (OptimizeCmpInstr(MI, MBB)) {
// MI is deleted.
Changed = true;
- MII = llvm::next(PMII);
+ MII = First ? I->begin() : llvm::next(PMII);
continue;
}
}
@@ -360,6 +361,8 @@
if (SeenMoveImm)
Changed |= FoldImmediate(MI, MBB, ImmDefRegs, ImmDefMIs);
}
+
+ First = false;
PMII = MII;
++MII;
}