[CodeGen] Widen non-power-of-2 vector HFA base types.

Currently, for the ppc64--gnu and aarch64 ABIs, we recognize:
  typedef __attribute__((__ext_vector_type__(3))) float v3f32;
  typedef __attribute__((__ext_vector_type__(16))) char v16i8;
  struct HFA {
    v3f32 a;
    v16i8 b;
  };

as an HFA. Since the first type encountered is used as the base type,
we pass the HFA as:
    [2 x <3 x float>]
Which leads to incorrect IR (relying on padding values) when the
second field is used.

Instead, explicitly widen the vector (after size rounding) in
isHomogeneousAggregate.

Differential Revision: http://reviews.llvm.org/D18998

llvm-svn: 266784

1 files changed, 12 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index a0cc7831871..8ad3290192b 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -4120,8 +4120,19 @@ bool ABIInfo::isHomogeneousAggregate(QualType Ty, const Type *&Base,
     // agree in both total size and mode (float vs. vector) are
     // treated as being equivalent here.
     const Type *TyPtr = Ty.getTypePtr();
-    if (!Base)
+    if (!Base) {
       Base = TyPtr;
+      // If it's a non-power-of-2 vector, its size is already a power-of-2,
+      // so make sure to widen it explicitly.
+      if (const VectorType *VT = Base->getAs<VectorType>()) {
+        QualType EltTy = VT->getElementType();
+        unsigned NumElements =
+            getContext().getTypeSize(VT) / getContext().getTypeSize(EltTy);
+        Base = getContext()
+                   .getVectorType(EltTy, NumElements, VT->getVectorKind())
+                   .getTypePtr();
+      }
+    }
 
     if (Base->isVectorType() != TyPtr->isVectorType() ||
         getContext().getTypeSize(Base) != getContext().getTypeSize(TyPtr))