MachineInstr *MI = MO.getParent();
// Do not replace if it is a phi's operand or is tied to def operand.
- if (MI->isPHI() || MI->isRegTiedToDefOperand(U.getOperandNo()))
+ if (MI->isPHI() || MI->isRegTiedToDefOperand(U.getOperandNo()) ||
+ MI->isPseudo())
continue;
MO.setReg(ZeroReg);
; CHECK: sync 0
}
+; make sure that this assertion in
+; TwoAddressInstructionPass::TryInstructionTransform does not fail:
+;
+; line 1203: assert(TargetRegisterInfo::isVirtualRegister(regB) &&
+;
+; it failed when MipsDAGToDAGISel::ReplaceUsesWithZeroReg replaced an
+; operand of an atomic instruction with register $zero.
+@a = external global i32
+
+define i32 @zeroreg() nounwind {
+entry:
+ %0 = cmpxchg i32* @a, i32 1, i32 0 seq_cst
+ %1 = icmp eq i32 %0, 1
+ %conv = zext i1 %1 to i32
+ ret i32 %conv
+}