ext_vector IRGen. Patch to allow indexing into

ext_vector_type's 'hi/lo' components when
used as lvalue. rdar://18031917 pr20697

llvm-svn: 215991

1 files changed, 35 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index c83cc0ad970..d632aba414c 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1361,6 +1361,28 @@ RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
   return RValue::get(Vec);
 }
 
+/// @brief Generates lvalue for partial ext_vector access.
+llvm::Value *CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
+  llvm::Value *VectorAddress = LV.getExtVectorAddr();
+  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
+  QualType EQT = ExprVT->getElementType();
+  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
+  llvm::Type *VectorElementPtrToTy = VectorElementTy->getPointerTo();
+  
+  llvm::Value *CastToPointerElement =
+    Builder.CreateBitCast(VectorAddress,
+                          VectorElementPtrToTy, "conv.ptr.element");
+  
+  const llvm::Constant *Elts = LV.getExtVectorElts();
+  unsigned ix = getAccessedFieldNo(0, Elts);
+  
+  llvm::Value *VectorBasePtrPlusIx =
+    Builder.CreateInBoundsGEP(CastToPointerElement,
+                              llvm::ConstantInt::get(SizeTy, ix), "add.ptr");
+  
+  return VectorBasePtrPlusIx;
+}
+
 /// @brief Load of global gamed gegisters are always calls to intrinsics.
 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
   assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
@@ -2323,7 +2345,8 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
 
   // If the base is a vector type, then we are forming a vector element lvalue
   // with this subscript.
-  if (E->getBase()->getType()->isVectorType()) {
+  if (E->getBase()->getType()->isVectorType() &&
+      !isa<ExtVectorElementExpr>(E->getBase())) {
     // Emit the vector as an lvalue to get its address.
     LValue LHS = EmitLValue(E->getBase());
     assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
@@ -2339,8 +2362,17 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
   // size is a VLA or Objective-C interface.
   llvm::Value *Address = nullptr;
   CharUnits ArrayAlignment;
-  if (const VariableArrayType *vla =
-        getContext().getAsVariableArrayType(E->getType())) {
+  if (isa<ExtVectorElementExpr>(E->getBase())) {
+    LValue LV = EmitLValue(E->getBase());
+    Address = EmitExtVectorElementLValue(LV);
+    Address = Builder.CreateInBoundsGEP(Address, Idx, "arrayidx");
+    const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
+    QualType EQT = ExprVT->getElementType();
+    return MakeAddrLValue(Address, EQT,
+                          getContext().getTypeAlignInChars(EQT));
+  }
+  else if (const VariableArrayType *vla =
+           getContext().getAsVariableArrayType(E->getType())) {
     // The base must be a pointer, which is not an aggregate.  Emit
     // it.  It needs to be emitted first in case it's what captures
     // the VLA bounds.