Fix pr3954. The register scavenger asserts for inline assembly with
register destinations that are tied to source operands. The
TargetInstrDescr::findTiedToSrcOperand method silently fails for inline
assembly. The existing MachineInstr::isRegReDefinedByTwoAddr was very
close to doing what is needed, so this revision makes a few changes to
that method and also renames it to isRegTiedToUseOperand (for consistency
with the very similar isRegTiedToDefOperand and because it handles both
two-address instructions and inline assembly with tied registers).
llvm-svn: 68714
diff --git a/llvm/lib/CodeGen/RegAllocSimple.cpp b/llvm/lib/CodeGen/RegAllocSimple.cpp
index 5e5290c..447e54c 100644
--- a/llvm/lib/CodeGen/RegAllocSimple.cpp
+++ b/llvm/lib/CodeGen/RegAllocSimple.cpp
@@ -204,8 +204,8 @@
unsigned physReg = Virt2PhysRegMap[virtualReg];
if (physReg == 0) {
if (MO.isDef()) {
- int TiedOp = Desc.findTiedToSrcOperand(i);
- if (TiedOp == -1) {
+ unsigned TiedOp;
+ if (!MI->isRegTiedToUseOperand(i, &TiedOp)) {
physReg = getFreeReg(virtualReg);
} else {
// must be same register number as the source operand that is