IRgen: Add CreateMemTemp, for creating an temporary memory object for a particular type, and flood fill. - CreateMemTemp sets the alignment on the alloca correctly, which fixes a great many places in IRgen where we were doing the wrong thing.

- This fixes many many more places than the test case, but my feeling is we need to audit alignment systematically so I'm not inclined to try hard to test the individual fixes in this patch. If this bothers you, patches welcome!

PR6240.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95648 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 11 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 943e890074..bb74f9b2f5 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -36,6 +36,14 @@ llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty,
   return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
 }
 
+llvm::Value *CodeGenFunction::CreateMemTemp(QualType Ty, const llvm::Twine &Name) {
+  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
+  // FIXME: Should we prefer the preferred type alignment here?
+  CharUnits Align = getContext().getTypeAlignInChars(Ty);
+  Alloc->setAlignment(Align.getQuantity());
+  return Alloc;
+}
+
 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
 /// expression and compare the result against zero, returning an Int1Ty value.
 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
@@ -195,8 +203,7 @@ RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
     Val = RValue::get(Val.getAggregateAddr());
   } else {
     // Create a temporary variable that we can bind the reference to.
-    llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()),
-                                         "reftmp");
+    llvm::Value *Temp = CreateMemTemp(E->getType(), "reftmp");
     if (Val.isScalar())
       EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
     else
@@ -1362,8 +1369,7 @@ EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
     llvm::Value *Vec = EmitScalarExpr(E->getBase());
     
     // Store the vector to memory (because LValue wants an address).
-    llvm::Value *VecMem = CreateTempAlloca(ConvertTypeForMem(
-                                             E->getBase()->getType()));
+    llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
     Builder.CreateStore(Vec, VecMem);
     Base = LValue::MakeAddr(VecMem, Qualifiers());
   }
@@ -1558,6 +1564,7 @@ CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
     if (!LHS.isSimple())
       return EmitUnsupportedLValue(E, "conditional operator");
 
+    // FIXME: We shouldn't need an alloca for this.
     llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
     Builder.CreateStore(LHS.getAddress(), Temp);
     EmitBranch(ContBlock);
@@ -1667,12 +1674,9 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
 LValue CodeGenFunction::EmitNullInitializationLValue(
                                               const CXXZeroInitValueExpr *E) {
   QualType Ty = E->getType();
-  llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty));
-  CharUnits Align = getContext().getTypeAlignInChars(Ty);
-  Alloc->setAlignment(Align.getQuantity());
-  LValue lvalue = LValue::MakeAddr(Alloc, Qualifiers());
-  EmitMemSetToZero(lvalue.getAddress(), Ty);
-  return lvalue;
+  LValue LV = LValue::MakeAddr(CreateMemTemp(Ty), MakeQualifiers(Ty));
+  EmitMemSetToZero(LV.getAddress(), Ty);
+  return LV;
 }
 
 //===--------------------------------------------------------------------===//
@@ -1767,7 +1771,7 @@ LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
 }
 
 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
-  llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), "tmp");
+  llvm::Value *Temp = CreateMemTemp(E->getType(), "tmp");
   EmitCXXConstructExpr(Temp, E);
   return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
 }