Mark RetBuf as SIMD variable

I see changes where storeIndir is used now instead of
a BLK copy, which is an IR shape improvement.

This improves codegen for SIMD8, degrades it for SIMD12 (due
to encoding size differences with SSE instructions, though
the IR looks better), and is neutral for SIMD16, in the
VectorReturn test.

Commit migrated from https://github.com/dotnet/coreclr/commit/9c6aab5e93199fe248195821b473b619f0a0f188

diff --git a/src/coreclr/src/jit/lclvars.cpp b/src/coreclr/src/jit/lclvars.cpp
index b51b1a8..3af0813 100644 (file)
--- a/src/coreclr/src/jit/lclvars.cpp
+++ b/src/coreclr/src/jit/lclvars.cpp
@@ -488,6 +488,16 @@ void Compiler::lvaInitRetBuffArg(InitVarDscInfo* varDscInfo)
                 varDsc->lvType = TYP_I_IMPL;
             }
         }
+#ifdef FEATURE_SIMD
+        else if (featureSIMD && varTypeIsSIMD(info.compRetType))
+        {
+            varDsc->lvSIMDType = true;
+            varDsc->lvBaseType =
+                getBaseTypeAndSizeOfSIMDType(info.compMethodInfo->args.retTypeClass, &varDsc->lvExactSize);
+            assert(varDsc->lvBaseType != TYP_UNKNOWN);
+        }
+#endif // FEATURE_SIMD
+
         assert(isValidIntArgReg(varDsc->lvArgReg));
 
 #ifdef DEBUG