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).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68714 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/CodeGen/Spiller.cpp b/lib/CodeGen/Spiller.cpp
index 7b2a32f..354ff0a 100644
--- a/lib/CodeGen/Spiller.cpp
+++ b/lib/CodeGen/Spiller.cpp
@@ -1589,8 +1589,8 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
       // If this def is part of a two-address operand, make sure to execute
       // the store from the correct physical register.
       unsigned PhysReg;
-      int TiedOp = MI.getDesc().findTiedToSrcOperand(i);
-      if (TiedOp != -1) {
+      unsigned TiedOp;
+      if (MI.isRegTiedToUseOperand(i, &TiedOp)) {
         PhysReg = MI.getOperand(TiedOp).getReg();
         if (SubIdx) {
           unsigned SuperReg = findSuperReg(RC, PhysReg, SubIdx, TRI);