Tighten lax vector-conversion rules and enforce them consistently.

When a lax conversion featured a vector and a non-vector, we were
only requiring the non-vector to be a scalar type, but really it
needs to be a real type (i.e. integral or real floating); it is
not reasonable to allow a pointer, member pointer, or complex
type here.

r198474 required lax conversions to match in "data size", i.e.
element size * element count, forbidding matches that happen
only because a vector is rounded up to the nearest power of two
in size.  Unfortunately, the erroneous logic was repeated in
several different places; unify them to use the new condition,
so that it triggers for arbitrary conversions and not just
those performed as part of binary operator checking.

rdar://15931426

llvm-svn: 200810

1 files changed, 5 insertions, 6 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 8e52e620a77..b95e2893189 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1372,7 +1372,7 @@ bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType,
 ///
 /// \param ICK Will be set to the vector conversion kind, if this is a vector
 /// conversion.
-static bool IsVectorConversion(ASTContext &Context, QualType FromType,
+static bool IsVectorConversion(Sema &S, QualType FromType,
                                QualType ToType, ImplicitConversionKind &ICK) {
   // We need at least one of these types to be a vector type to have a vector
   // conversion.
@@ -1380,7 +1380,7 @@ static bool IsVectorConversion(ASTContext &Context, QualType FromType,
     return false;
 
   // Identical types require no conversions.
-  if (Context.hasSameUnqualifiedType(FromType, ToType))
+  if (S.Context.hasSameUnqualifiedType(FromType, ToType))
     return false;
 
   // There are no conversions between extended vector types, only identity.
@@ -1402,9 +1402,8 @@ static bool IsVectorConversion(ASTContext &Context, QualType FromType,
   // 2)lax vector conversions are permitted and the vector types are of the
   //   same size
   if (ToType->isVectorType() && FromType->isVectorType()) {
-    if (Context.areCompatibleVectorTypes(FromType, ToType) ||
-        (Context.getLangOpts().LaxVectorConversions &&
-         (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) {
+    if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
+        S.isLaxVectorConversion(FromType, ToType)) {
       ICK = ICK_Vector_Conversion;
       return true;
     }
@@ -1633,7 +1632,7 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
                                          InOverloadResolution, FromType)) {
     // Pointer to member conversions (4.11).
     SCS.Second = ICK_Pointer_Member;
-  } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) {
+  } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
     SCS.Second = SecondICK;
     FromType = ToType.getUnqualifiedType();
   } else if (!S.getLangOpts().CPlusPlus &&