[globalisel] Correct r331816 to check the opcode before calling getOperand().

Fix a silly mistake in my pre-commit changes for r331816. It should check what
opcode the insn is before extracting the operands.

NFC at the moment since the caller already checked the opcode.

llvm-svn: 331820

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
index 25b40da..da797ee 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -37,14 +37,14 @@ bool CombinerHelper::tryCombineCopy(MachineInstr &MI) {
 }
 
 bool CombinerHelper::tryCombineExtendingLoads(MachineInstr &MI) {
-  unsigned DstReg = MI.getOperand(0).getReg();
-  unsigned SrcReg = MI.getOperand(1).getReg();
-
   if (MI.getOpcode() != TargetOpcode::G_ANYEXT &&
       MI.getOpcode() != TargetOpcode::G_SEXT &&
       MI.getOpcode() != TargetOpcode::G_ZEXT)
     return false;
 
+  unsigned DstReg = MI.getOperand(0).getReg();
+  unsigned SrcReg = MI.getOperand(1).getReg();
+
   LLT DstTy = MRI.getType(DstReg);
   if (!DstTy.isScalar())
     return false;
@@ -69,5 +69,5 @@ bool CombinerHelper::tryCombineExtendingLoads(MachineInstr &MI) {
 bool CombinerHelper::tryCombine(MachineInstr &MI) {
   if (tryCombineCopy(MI))
     return true;
-  return tryCombineExtendingLoads(MI);;
+  return tryCombineExtendingLoads(MI);
 }