Make TargetLowering::getTypeConversion more resilient against odd illegal MVTs.

- An MVT can become an EVT when being split (e.g. v2i8 -> v1i8, the latter doesn't exist)
- Return the scalar value when an MVT is scalarized (v1i64 -> i64)

Fixes PR14639ff.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170546 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 2 deletions

diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index e159454934..f2ec08d93b 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -2005,8 +2005,11 @@ public:
          && "Promote may not follow Expand or Promote");
 
       if (LA == TypeSplitVector)
-        NVT = MVT::getVectorVT(SVT.getVectorElementType(),
-                               SVT.getVectorNumElements() / 2);
+        return LegalizeKind(LA, EVT::getVectorVT(Context,
+                                                 SVT.getVectorElementType(),
+                                                 SVT.getVectorNumElements()/2));
+      if (LA == TypeScalarizeVector)
+        return LegalizeKind(LA, SVT.getVectorElementType());
       return LegalizeKind(LA, NVT);
     }