From a64378048341b174d40552b7b0b3e79daf72cdad Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 5 Feb 2010 21:10:36 +0000
Subject: [PATCH] Revert r95393, which broke Clang's self-host.

llvm-svn: 95430
---
 clang/lib/CodeGen/CGDecl.cpp | 24 +++++++++++++++---------
 clang/lib/CodeGen/CGExpr.cpp |  5 +++--
 clang/lib/CodeGen/CGStmt.cpp |  5 +++--
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index d18b87fb9ac6..e27c5e4e51ae 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -690,19 +690,25 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg) {
   CanQualType CTy = getContext().getCanonicalType(Ty);
 
   llvm::Value *DeclPtr;
-  // If this is an aggregate or variable sized value, reuse the input pointer.
-  if (!Ty->isConstantSizeType() ||
-      CodeGenFunction::hasAggregateLLVMType(Ty)) {
+  if (!Ty->isConstantSizeType()) {
+    // Variable sized values always are passed by-reference.
     DeclPtr = Arg;
   } else {
-    // Otherwise, create a temporary to hold the value.
-    DeclPtr = CreateTempAlloca(ConvertTypeForMem(Ty));
-    DeclPtr->setName(D.getName() + ".addr");
+    // A fixed sized single-value variable becomes an alloca in the entry block.
+    const llvm::Type *LTy = ConvertTypeForMem(Ty);
+    if (LTy->isSingleValueType()) {
+      // TODO: Alignment
+      DeclPtr = CreateTempAlloca(LTy);
+      DeclPtr->setName(D.getNameAsString() + llvm::StringRef(".addr"));
 
-    // Store the initial value into the alloca.
-    EmitStoreOfScalar(Arg, DeclPtr, CTy.isVolatileQualified(), Ty);
+      // Store the initial value into the alloca.
+      EmitStoreOfScalar(Arg, DeclPtr, CTy.isVolatileQualified(), Ty);
+    } else {
+      // Otherwise, if this is an aggregate, just use the input pointer.
+      DeclPtr = Arg;
+    }
+    Arg->setName(D.getNameAsString());
   }
-  Arg->setName(D.getName());
 
   llvm::Value *&DMEntry = LocalDeclMap[&D];
   assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 2684eb6e3ce1..7fb79e958552 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -549,13 +549,14 @@ RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) {
 
   if (LV.isSimple()) {
     llvm::Value *Ptr = LV.getAddress();
+    const llvm::Type *EltTy =
+      cast<llvm::PointerType>(Ptr->getType())->getElementType();
 
     // Simple scalar l-value.
-    if (!CodeGenFunction::hasAggregateLLVMType(ExprType))
+    if (EltTy->isSingleValueType())
       return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
                                           ExprType));
 
-    // FIXME: This case shouldn't be necessary?
     assert(ExprType->isFunctionType() && "Unknown scalar value");
     return RValue::get(Ptr);
   }
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 008a480b9c12..7ea8b08c238e 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -861,13 +861,14 @@ llvm::Value* CodeGenFunction::EmitAsmInput(const AsmStmt &S,
                                            std::string &ConstraintStr) {
   llvm::Value *Arg;
   if (Info.allowsRegister() || !Info.allowsMemory()) {
-    if (!CodeGenFunction::hasAggregateLLVMType(InputExpr->getType())) {
+    const llvm::Type *Ty = ConvertType(InputExpr->getType());
+
+    if (Ty->isSingleValueType()) {
       Arg = EmitScalarExpr(InputExpr);
     } else {
       InputExpr = InputExpr->IgnoreParenNoopCasts(getContext());
       LValue Dest = EmitLValue(InputExpr);
 
-      const llvm::Type *Ty = ConvertType(InputExpr->getType());
       uint64_t Size = CGM.getTargetData().getTypeSizeInBits(Ty);
       if (Size <= 64 && llvm::isPowerOf2_64(Size)) {
         Ty = llvm::IntegerType::get(VMContext, Size);