commuteInstr() can now commute non-ssa machine instrs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47043 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 42c994a..cfbce7e 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -1055,6 +1055,15 @@
unsigned C = MI->getOperand(2).getReg();
bool BisKill = MI->getOperand(1).isKill();
bool CisKill = MI->getOperand(2).isKill();
+ // If machine instrs are no longer in two-address forms, update
+ // destination register as well.
+ if (A == B) {
+ // Must be two address instruction!
+ assert(MI->getDesc().getOperandConstraint(0, TOI::TIED_TO) &&
+ "Expecting a two-address instruction!");
+ A = C;
+ CisKill = false;
+ }
return BuildMI(get(Opc), A).addReg(C, false, false, CisKill)
.addReg(B, false, false, BisKill).addImm(Size-Amt);
}