Don't modify MO while use_iterator is still pointing to it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161626 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
index e1d6212..5a97c17 100644 (file)
--- a/lib/Target/Mips/MipsISelDAGToDAG.cpp
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -242,13 +242,14 @@ bool MipsDAGToDAGISel::ReplaceUsesWithZeroReg(MachineRegisterInfo *MRI,
 
   // Replace uses with ZeroReg.
   for (MachineRegisterInfo::use_iterator U = MRI->use_begin(DstReg),
-       E = MRI->use_end(); U != E; ++U) {
+       E = MRI->use_end(); U != E;) {
     MachineOperand &MO = U.getOperand();
+    unsigned OpNo = U.getOperandNo();
     MachineInstr *MI = MO.getParent();
+    ++U;
 
     // Do not replace if it is a phi's operand or is tied to def operand.
-    if (MI->isPHI() || MI->isRegTiedToDefOperand(U.getOperandNo()) ||
-        MI->isPseudo())
+    if (MI->isPHI() || MI->isRegTiedToDefOperand(OpNo) || MI->isPseudo())
       continue;
 
     MO.setReg(ZeroReg);

diff --git a/test/CodeGen/Mips/swzero.ll b/test/CodeGen/Mips/swzero.ll
index 2441ca2..9f91a39 100644 (file)
--- a/test/CodeGen/Mips/swzero.ll
+++ b/test/CodeGen/Mips/swzero.ll
@@ -4,6 +4,7 @@
 
 define void @zero_u(%struct.unaligned* nocapture %p) nounwind {
 entry:
+; CHECK: swl $zero
 ; CHECK: swr $zero
   %x = getelementptr inbounds %struct.unaligned* %p, i32 0, i32 0
   store i32 0, i32* %x, align 1