[AMDGPU] Use custom inserter for gfx10 VOP2b

This is part of the approved D63204 pending parent revision.
This small change is in fact a part of the VOP2b legalization which
does not technically belong to wave32 support, so extracted
separately.

llvm-svn: 363625

Author: rampitec

llvm/lib/Target/AMDGPU/VOP2Instructions.td

@@ -175,7 +175,9 @@ multiclass VOP2bInst <string opName,
     let SchedRW = [Write32Bit, WriteSALU] in {
       let Uses = !if(useSGPRInput, [VCC, EXEC], [EXEC]), Defs = [VCC] in {
         def _e32 : VOP2_Pseudo <opName, P, VOPPatOrNull<node,P>.ret>,
-                   Commutable_REV<revOp#"_e32", !eq(revOp, opName)>;
+                   Commutable_REV<revOp#"_e32", !eq(revOp, opName)> {
+          let usesCustomInserter = !eq(P.NumSrcArgs, 2);
+        }
 
         def _sdwa  : VOP2_SDWA_Pseudo <opName, P> {
           let AsmMatchConverter = "cvtSdwaVOP2b";