Teach TargetData to handle 'preferred' alignment for each target, and use

these alignment amounts to align scalars when we can.  Patch by Scott Michel!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33409 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/ELFWriter.cpp

@@ -241,7 +241,7 @@ void ELFWriter::EmitGlobal(GlobalVariable *GV) {
   }
 
   const Type *GVType = (const Type*)GV->getType();
-  unsigned Align = TM.getTargetData()->getTypeAlignment(GVType);
+  unsigned Align = TM.getTargetData()->getTypeAlignmentPref(GVType);
   unsigned Size  = TM.getTargetData()->getTypeSize(GVType);
 
   // If this global has a zero initializer, it is part of the .bss or common

lib/CodeGen/MachOWriter.cpp

@@ -309,7 +309,7 @@ void MachOWriter::AddSymbolToSection(MachOSection *Sec, GlobalVariable *GV) {
   unsigned Size = TM.getTargetData()->getTypeSize(Ty);
   unsigned Align = GV->getAlignment();
   if (Align == 0)
-    Align = TM.getTargetData()->getTypeAlignment(Ty);
+    Align = TM.getTargetData()->getTypeAlignmentPref(Ty);
   
   MachOSym Sym(GV, Mang->getValueName(GV), Sec->Index, TM);
   

lib/CodeGen/MachineFunction.cpp

@@ -123,7 +123,8 @@ MachineFunction::MachineFunction(const Function *F,
   const TargetData &TD = *TM.getTargetData();
   bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
   unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
-  unsigned Alignment = IsPic ? TD.getIntAlignment() : TD.getPointerAlignment();
+  unsigned Alignment = IsPic ? TD.getIntABIAlignment()
+                             : TD.getPointerABIAlignment();
   JumpTableInfo = new MachineJumpTableInfo(EntrySize, Alignment);
   
   BasicBlocks.Parent = this;

lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

@@ -3029,7 +3029,7 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
         // new ones, as reuse may inhibit scheduling.
         const Type *Ty = MVT::getTypeForValueType(ExtraVT);
         unsigned TySize = (unsigned)TLI.getTargetData()->getTypeSize(Ty);
-        unsigned Align  = TLI.getTargetData()->getTypeAlignment(Ty);
+        unsigned Align  = TLI.getTargetData()->getTypeAlignmentPref(Ty);
         MachineFunction &MF = DAG.getMachineFunction();
         int SSFI =
           MF.getFrameInfo()->CreateStackObject((unsigned)TySize, Align);
@@ -3937,7 +3937,9 @@ SDOperand SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
 SDOperand SelectionDAGLegalize::CreateStackTemporary(MVT::ValueType VT) {
   MachineFrameInfo *FrameInfo = DAG.getMachineFunction().getFrameInfo();
   unsigned ByteSize = MVT::getSizeInBits(VT)/8;
-  int FrameIdx = FrameInfo->CreateStackObject(ByteSize, ByteSize);
+  const Type *Ty = MVT::getTypeForValueType(VT);
+  unsigned StackAlign = (unsigned)TLI.getTargetData()->getTypeAlignmentPref(Ty);
+  int FrameIdx = FrameInfo->CreateStackObject(ByteSize, StackAlign);
   return DAG.getFrameIndex(FrameIdx, TLI.getPointerTy());
 }
 
@@ -4242,9 +4244,12 @@ SDOperand SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned,
   if (Op0.getValueType() == MVT::i32) {
     // simple 32-bit [signed|unsigned] integer to float/double expansion
     
-    // get the stack frame index of a 8 byte buffer
+    // get the stack frame index of a 8 byte buffer, pessimistically aligned
     MachineFunction &MF = DAG.getMachineFunction();
-    int SSFI = MF.getFrameInfo()->CreateStackObject(8, 8);
+    const Type *F64Type = MVT::getTypeForValueType(MVT::f64);
+    unsigned StackAlign =
+      (unsigned)TLI.getTargetData()->getTypeAlignmentPref(F64Type);
+    int SSFI = MF.getFrameInfo()->CreateStackObject(8, StackAlign);
     // get address of 8 byte buffer
     SDOperand StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy());
     // word offset constant for Hi/Lo address computation

lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -244,17 +244,9 @@ FunctionLoweringInfo::FunctionLoweringInfo(TargetLowering &tli,
         const Type *Ty = AI->getAllocatedType();
         uint64_t TySize = TLI.getTargetData()->getTypeSize(Ty);
         unsigned Align = 
-          std::max((unsigned)TLI.getTargetData()->getTypeAlignment(Ty),
+          std::max((unsigned)TLI.getTargetData()->getTypeAlignmentPref(Ty),
                    AI->getAlignment());
 
-        // If the alignment of the value is smaller than the size of the 
-        // value, and if the size of the value is particularly small 
-        // (<= 8 bytes), round up to the size of the value for potentially 
-        // better performance.
-        //
-        // FIXME: This could be made better with a preferred alignment hook in
-        // TargetData.  It serves primarily to 8-byte align doubles for X86.
-        if (Align < TySize && TySize <= 8) Align = TySize;
         TySize *= CUI->getZExtValue();   // Get total allocated size.
         if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
         StaticAllocaMap[AI] =
@@ -1729,8 +1721,9 @@ void SelectionDAGLowering::visitAlloca(AllocaInst &I) {
 
   const Type *Ty = I.getAllocatedType();
   uint64_t TySize = TLI.getTargetData()->getTypeSize(Ty);
-  unsigned Align = std::max((unsigned)TLI.getTargetData()->getTypeAlignment(Ty),
-                            I.getAlignment());
+  unsigned Align =
+    std::max((unsigned)TLI.getTargetData()->getTypeAlignmentPref(Ty),
+             I.getAlignment());
 
   SDOperand AllocSize = getValue(I.getArraySize());
   MVT::ValueType IntPtr = TLI.getPointerTy();