From 85d2bbc2ddb28164ea15e0e152bc44afdbc04ab3 Mon Sep 17 00:00:00 2001
From: Egor Chesakov <Egor.Chesakov@microsoft.com>
Date: Fri, 7 Aug 2020 17:28:41 -0700
Subject: [PATCH] When returning a SIMD value use v0 register as the candidate
 for source operand of GT_RETURN in case when it is a single-register local
 variable

---
 src/coreclr/src/jit/lsrabuild.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/src/jit/lsrabuild.cpp b/src/coreclr/src/jit/lsrabuild.cpp
index d902b3a..e2f8775 100644
--- a/src/coreclr/src/jit/lsrabuild.cpp
+++ b/src/coreclr/src/jit/lsrabuild.cpp
@@ -3443,10 +3443,15 @@ int LinearScan::BuildReturn(GenTree* tree)
         if (varTypeIsSIMD(tree) && !op1->IsMultiRegLclVar())
         {
             useCandidates = allSIMDRegs();
+            if (op1->OperGet() == GT_LCL_VAR)
+            {
+                assert(op1->TypeGet() != TYP_SIMD32);
+                useCandidates = RBM_DOUBLERET;
+            }
             BuildUse(op1, useCandidates);
             return 1;
         }
-#endif // !TARGET_ARM64
+#endif // TARGET_ARM64
 
         if (varTypeIsStruct(tree))
         {
-- 
2.7.4