Implement "AsCheapAsAMove" for some obviously cheap instructions: xor and the

[oota-llvm.git] / lib / Target / TargetData.cpp

diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index 6d566693e8507be9fa499acb8391d19ff3b035c9..69a8ca902b4285407f248670a7ea3790ee799e95 100644 (file)
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -27,14 +27,13 @@
 #include "llvm/ADT/StringExtras.h"
 #include <algorithm>
 #include <cstdlib>
-#include <sstream>
 using namespace llvm;
 
 // Handle the Pass registration stuff necessary to use TargetData's.
-namespace {
-  // Register the default SparcV9 implementation...
-  RegisterPass<TargetData> X("targetdata", "Target Data Layout");
-}
+
+// Register the default SparcV9 implementation...
+static RegisterPass<TargetData> X("targetdata", "Target Data Layout", false, 
+                                  true);
 char TargetData::ID = 0;
 
 //===----------------------------------------------------------------------===//
@@ -101,6 +100,7 @@ unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
 TargetAlignElem
 TargetAlignElem::get(AlignTypeEnum align_type, unsigned char abi_align,
                      unsigned char pref_align, uint32_t bit_width) {
+  assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
   TargetAlignElem retval;
   retval.AlignType = align_type;
   retval.ABIAlign = abi_align;
@@ -242,6 +242,7 @@ TargetData::TargetData(const Module *M)
 void
 TargetData::setAlignment(AlignTypeEnum align_type, unsigned char abi_align,
                          unsigned char pref_align, uint32_t bit_width) {
+  assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
   for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
     if (Alignments[i].AlignType == align_type &&
         Alignments[i].TypeBitWidth == bit_width) {
@@ -316,6 +317,8 @@ unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType,
                  : Alignments[BestMatchIdx].PrefAlign;
 }
 
+namespace {
+
 /// LayoutInfo - The lazy cache of structure layout information maintained by
 /// TargetData.  Note that the struct types must have been free'd before
 /// llvm_shutdown is called (and thus this is deallocated) because all the
@@ -340,8 +343,10 @@ struct DenseMapLayoutKeyInfo {
 };
 
 typedef DenseMap<LayoutKey, StructLayout*, DenseMapLayoutKeyInfo> LayoutInfoTy;
-static ManagedStatic<LayoutInfoTy> LayoutInfo;
 
+}
+
+static ManagedStatic<LayoutInfoTy> LayoutInfo;
 
 TargetData::~TargetData() {
   if (LayoutInfo.isConstructed()) {
@@ -576,22 +581,29 @@ uint64_t TargetData::getIndexedOffset(const Type *ptrTy, Value* const* Indices,
   return Result;
 }
 
-/// getPreferredAlignmentLog - Return the preferred alignment of the
-/// specified global, returned in log form.  This includes an explicitly
-/// requested alignment (if the global has one).
-unsigned TargetData::getPreferredAlignmentLog(const GlobalVariable *GV) const {
+/// getPreferredAlignment - Return the preferred alignment of the specified
+/// global.  This includes an explicitly requested alignment (if the global
+/// has one).
+unsigned TargetData::getPreferredAlignment(const GlobalVariable *GV) const {
   const Type *ElemType = GV->getType()->getElementType();
-  unsigned Alignment = getPreferredTypeAlignmentShift(ElemType);
-  if (GV->getAlignment() > (1U << Alignment))
-    Alignment = Log2_32(GV->getAlignment());
-  
+  unsigned Alignment = getPrefTypeAlignment(ElemType);
+  if (GV->getAlignment() > Alignment)
+    Alignment = GV->getAlignment();
+
   if (GV->hasInitializer()) {
-    if (Alignment < 4) {
+    if (Alignment < 16) {
       // If the global is not external, see if it is large.  If so, give it a
       // larger alignment.
       if (getTypeSizeInBits(ElemType) > 128)
-        Alignment = 4;    // 16-byte alignment.
+        Alignment = 16;    // 16-byte alignment.
     }
   }
   return Alignment;
 }
+
+/// getPreferredAlignmentLog - Return the preferred alignment of the
+/// specified global, returned in log form.  This includes an explicitly
+/// requested alignment (if the global has one).
+unsigned TargetData::getPreferredAlignmentLog(const GlobalVariable *GV) const {
+  return Log2_32(getPreferredAlignment(GV));
+}