Minor bug fix. LowerSubregs should translate

%S0<def> = EXTRACT_SUBREG %Q0<kill>, 1
to
%S0<def> = IMPLICIT_DEF %Q0<imp-use,kill>

Implicit_def does not *read* any register so the operand should be marked "implicit". The missing "implicit" marker on the operand is wrong, but it doesn't actually break anything.

llvm-svn: 82503

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/LowerSubregs.cpp b/llvm/lib/CodeGen/LowerSubregs.cpp
index 812d97d66c3..f3157f008b9 100644
--- a/llvm/lib/CodeGen/LowerSubregs.cpp
+++ b/llvm/lib/CodeGen/LowerSubregs.cpp
@@ -130,6 +130,7 @@ bool LowerSubregsInstructionPass::LowerExtract(MachineInstr *MI) {
       // instruction with IMPLICIT_DEF.
       MI->setDesc(TII.get(TargetInstrInfo::IMPLICIT_DEF));
       MI->RemoveOperand(2);     // SubIdx
+      MI->getOperand(1).setImplicit(true);
       DEBUG(errs() << "subreg: replace by: " << *MI);
       return true;
     }