From 364d73ddab43b699ab90240f11b7a2eb5cf69bd8 Mon Sep 17 00:00:00 2001
From: Mon P Wang <wangmp@apple.com>
Date: Sat, 5 Jul 2008 20:40:31 +0000
Subject: [PATCH] Fixed generating incorrect aligned stores that I backout of
 r53031 that fixed problems in EmitStackConvert where the source and target
 type have different alignment by creating a stack slot with the max alignment
 of source and target type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53150 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/SelectionDAG.h       |  7 ++++---
 lib/CodeGen/SelectionDAG/LegalizeDAG.cpp  | 24 ++++++++++++++---------
 lib/CodeGen/SelectionDAG/SelectionDAG.cpp |  7 ++++---
 3 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 7ebc698bad3..4f532ba43bf 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -589,9 +589,10 @@ public:
   void dump() const;
 
   /// CreateStackTemporary - Create a stack temporary, suitable for holding the
-  /// specified value type.
-  SDOperand CreateStackTemporary(MVT VT);
-
+  /// specified value type.  If minAlign is specified, the slot size will have
+  /// at least that alignment.
+  SDOperand CreateStackTemporary(MVT VT, unsigned minAlign = 1);
+  
   /// FoldSetCC - Constant fold a setcc to true or false.
   SDOperand FoldSetCC(MVT VT, SDOperand N1,
                       SDOperand N2, ISD::CondCode Cond);
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index d929ec01c31..3695580a92b 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -4871,35 +4871,41 @@ SDOperand SelectionDAGLegalize::EmitStackConvert(SDOperand SrcOp,
                                                  MVT SlotVT,
                                                  MVT DestVT) {
   // Create the stack frame object.
-  SDOperand FIPtr = DAG.CreateStackTemporary(SlotVT);
-
+  unsigned SrcAlign = TLI.getTargetData()->getPrefTypeAlignment(
+                                          SrcOp.getValueType().getTypeForMVT());
+  SDOperand FIPtr = DAG.CreateStackTemporary(SlotVT, SrcAlign);
+  
   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
   int SPFI = StackPtrFI->getIndex();
-
+  
   unsigned SrcSize = SrcOp.getValueType().getSizeInBits();
   unsigned SlotSize = SlotVT.getSizeInBits();
   unsigned DestSize = DestVT.getSizeInBits();
+  unsigned DestAlign = TLI.getTargetData()->getPrefTypeAlignment(
+                                                        DestVT.getTypeForMVT());
   
   // Emit a store to the stack slot.  Use a truncstore if the input value is
   // later than DestVT.
   SDOperand Store;
+  
   if (SrcSize > SlotSize)
     Store = DAG.getTruncStore(DAG.getEntryNode(), SrcOp, FIPtr,
-                              PseudoSourceValue::getFixedStack(),
-                              SPFI, SlotVT);
+                              PseudoSourceValue::getFixedStack(), SPFI, SlotVT, 
+                              false, SrcAlign);
   else {
     assert(SrcSize == SlotSize && "Invalid store");
     Store = DAG.getStore(DAG.getEntryNode(), SrcOp, FIPtr,
-                         PseudoSourceValue::getFixedStack(),
-                         SPFI);
+                         PseudoSourceValue::getFixedStack(), SPFI,
+                         false, SrcAlign);
   }
   
   // Result is a load from the stack slot.
   if (SlotSize == DestSize)
-    return DAG.getLoad(DestVT, Store, FIPtr, NULL, 0);
+    return DAG.getLoad(DestVT, Store, FIPtr, NULL, 0, false, DestAlign);
   
   assert(SlotSize < DestSize && "Unknown extension!");
-  return DAG.getExtLoad(ISD::EXTLOAD, DestVT, Store, FIPtr, NULL, 0, SlotVT);
+  return DAG.getExtLoad(ISD::EXTLOAD, DestVT, Store, FIPtr, NULL, 0, SlotVT,
+                        false, DestAlign);
 }
 
 SDOperand SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index c457c4bb767..d6a38be667f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1080,16 +1080,17 @@ SDOperand SelectionDAG::getMemOperand(const MachineMemOperand &MO) {
 
 /// CreateStackTemporary - Create a stack temporary, suitable for holding the
 /// specified value type.
-SDOperand SelectionDAG::CreateStackTemporary(MVT VT) {
+SDOperand SelectionDAG::CreateStackTemporary(MVT VT, unsigned minAlign) {
   MachineFrameInfo *FrameInfo = getMachineFunction().getFrameInfo();
   unsigned ByteSize = VT.getSizeInBits()/8;
   const Type *Ty = VT.getTypeForMVT();
-  unsigned StackAlign = (unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty);
+  unsigned StackAlign =
+  std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty), minAlign);
+  
   int FrameIdx = FrameInfo->CreateStackObject(ByteSize, StackAlign);
   return getFrameIndex(FrameIdx, TLI.getPointerTy());
 }
 
-
 SDOperand SelectionDAG::FoldSetCC(MVT VT, SDOperand N1,
                                   SDOperand N2, ISD::CondCode Cond) {
   // These setcc operations always fold.