Update CreateMalloc so that its callers specify the size to allocate:

MallocInst-autoupgrade users use non-TargetData-computed allocation sizes.
Optimization uses use TargetData to compute the allocation size.

Now that malloc calls can have constant sizes, update isArrayMallocHelper() to use TargetData to determine the size of the malloced type and the size of malloced arrays.
Extend getMallocType() to support malloc calls that have non-bitcast uses.

Update OptimizeGlobalAddressOfMalloc() to optimize malloc calls that have non-bitcast uses.  The bitcast use of a malloc call has to be treated specially here because the uses of the bitcast need to be replaced and the bitcast needs to be erased (just like the malloc call) for OptimizeGlobalAddressOfMalloc() to work correctly.

Update PerformHeapAllocSRoA() to optimize malloc calls that have non-bitcast uses.  The bitcast use of the malloc is not handled specially here because ReplaceUsesOfMallocWithGlobal replaces through the bitcast use.

Update OptimizeOnceStoredGlobal() to not care about the malloc calls' bitcast use.

Update all globalopt malloc tests to not rely on autoupgraded-MallocInsts, but instead use explicit malloc calls with correct allocation sizes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86077 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 41 insertions, 35 deletions

diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index e710350..f4eb793 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Instructions.h"
 #include "llvm/Module.h"
 #include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Target/TargetData.h"
 using namespace llvm;
 
 //===----------------------------------------------------------------------===//
@@ -96,45 +97,47 @@ static Value *isArrayMallocHelper(const CallInst *CI, LLVMContext &Context,
   if (!CI)
     return NULL;
 
-  // Type must be known to determine array size.
+  // The size of the malloc's result type must be known to determine array size.
   const Type *T = getMallocAllocatedType(CI);
-  if (!T)
+  if (!T || !T->isSized() || !TD)
     return NULL;
 
   Value *MallocArg = CI->getOperand(1);
+  const Type *ArgType = MallocArg->getType();
   ConstantExpr *CO = dyn_cast<ConstantExpr>(MallocArg);
   BinaryOperator *BO = dyn_cast<BinaryOperator>(MallocArg);
 
-  Constant *ElementSize = ConstantExpr::getSizeOf(T);
-  ElementSize = ConstantExpr::getTruncOrBitCast(ElementSize, 
-                                                MallocArg->getType());
-  Constant *FoldedElementSize =
-   ConstantFoldConstantExpression(cast<ConstantExpr>(ElementSize), Context, TD);
+  unsigned ElementSizeInt = TD->getTypeAllocSize(T);
+  if (const StructType *ST = dyn_cast<StructType>(T))
+    ElementSizeInt = TD->getStructLayout(ST)->getSizeInBytes();
+  Constant *ElementSize = ConstantInt::get(ArgType, ElementSizeInt);
 
   // First, check if CI is a non-array malloc.
-  if (CO && ((CO == ElementSize) ||
-             (FoldedElementSize && (CO == FoldedElementSize))))
+  if (CO && CO == ElementSize)
     // Match CreateMalloc's use of constant 1 array-size for non-array mallocs.
-    return ConstantInt::get(MallocArg->getType(), 1);
+    return ConstantInt::get(ArgType, 1);
 
   // Second, check if CI is an array malloc whose array size can be determined.
-  if (isConstantOne(ElementSize) || 
-      (FoldedElementSize && isConstantOne(FoldedElementSize)))
+  if (isConstantOne(ElementSize))
     return MallocArg;
 
+  if (ConstantInt *CInt = dyn_cast<ConstantInt>(MallocArg))
+    if (CInt->getZExtValue() % ElementSizeInt == 0)
+      return ConstantInt::get(ArgType, CInt->getZExtValue() / ElementSizeInt);
+
   if (!CO && !BO)
     return NULL;
 
   Value *Op0 = NULL;
   Value *Op1 = NULL;
   unsigned Opcode = 0;
-  if (CO && ((CO->getOpcode() == Instruction::Mul) || 
+  if (CO && ((CO->getOpcode() == Instruction::Mul) ||
              (CO->getOpcode() == Instruction::Shl))) {
     Op0 = CO->getOperand(0);
     Op1 = CO->getOperand(1);
     Opcode = CO->getOpcode();
   }
-  if (BO && ((BO->getOpcode() == Instruction::Mul) || 
+  if (BO && ((BO->getOpcode() == Instruction::Mul) ||
              (BO->getOpcode() == Instruction::Shl))) {
     Op0 = BO->getOperand(0);
     Op1 = BO->getOperand(1);
@@ -144,12 +147,10 @@ static Value *isArrayMallocHelper(const CallInst *CI, LLVMContext &Context,
   // Determine array size if malloc's argument is the product of a mul or shl.
   if (Op0) {
     if (Opcode == Instruction::Mul) {
-      if ((Op1 == ElementSize) ||
-          (FoldedElementSize && (Op1 == FoldedElementSize)))
+      if (Op1 == ElementSize)
         // ArraySize * ElementSize
         return Op0;
-      if ((Op0 == ElementSize) ||
-          (FoldedElementSize && (Op0 == FoldedElementSize)))
+      if (Op0 == ElementSize)
         // ElementSize * ArraySize
         return Op1;
     }
@@ -161,11 +162,10 @@ static Value *isArrayMallocHelper(const CallInst *CI, LLVMContext &Context,
       uint64_t BitToSet = Op1Int.getLimitedValue(Op1Int.getBitWidth() - 1);
       Value *Op1Pow = ConstantInt::get(Context, 
                                   APInt(Op1Int.getBitWidth(), 0).set(BitToSet));
-      if (Op0 == ElementSize || (FoldedElementSize && Op0 == FoldedElementSize))
+      if (Op0 == ElementSize)
         // ArraySize << log2(ElementSize)
         return Op1Pow;
-      if (Op1Pow == ElementSize ||
-          (FoldedElementSize && Op1Pow == FoldedElementSize))
+      if (Op1Pow == ElementSize)
         // ElementSize << log2(ArraySize)
         return Op0;
     }
@@ -205,35 +205,41 @@ const CallInst *llvm::isArrayMalloc(const Value *I, LLVMContext &Context,
 }
 
 /// getMallocType - Returns the PointerType resulting from the malloc call.
-/// This PointerType is the result type of the call's only bitcast use.
-/// If there is no unique bitcast use, then return NULL.
+/// The PointerType depends on the number of bitcast uses of the malloc call:
+///   0: PointerType is the calls' return type.
+///   1: PointerType is the bitcast's result type.
+///  >1: Unique PointerType cannot be determined, return NULL.
 const PointerType *llvm::getMallocType(const CallInst *CI) {
   assert(isMalloc(CI) && "GetMallocType and not malloc call");
   
-  const BitCastInst *BCI = NULL;
-  
+  const PointerType *MallocType = NULL;
+  unsigned NumOfBitCastUses = 0;
+
   // Determine if CallInst has a bitcast use.
   for (Value::use_const_iterator UI = CI->use_begin(), E = CI->use_end();
        UI != E; )
-    if ((BCI = dyn_cast<BitCastInst>(cast<Instruction>(*UI++))))
-      break;
+    if (const BitCastInst *BCI = dyn_cast<BitCastInst>(*UI++)) {
+      MallocType = cast<PointerType>(BCI->getDestTy());
+      NumOfBitCastUses++;
+    }
 
-  // Malloc call has 1 bitcast use and no other uses, so type is the bitcast's
-  // destination type.
-  if (BCI && CI->hasOneUse())
-    return cast<PointerType>(BCI->getDestTy());
+  // Malloc call has 1 bitcast use, so type is the bitcast's destination type.
+  if (NumOfBitCastUses == 1)
+    return MallocType;
 
   // Malloc call was not bitcast, so type is the malloc function's return type.
-  if (!BCI)
+  if (NumOfBitCastUses == 0)
     return cast<PointerType>(CI->getType());
 
   // Type could not be determined.
   return NULL;
 }
 
-/// getMallocAllocatedType - Returns the Type allocated by malloc call. This
-/// Type is the result type of the call's only bitcast use. If there is no
-/// unique bitcast use, then return NULL.
+/// getMallocAllocatedType - Returns the Type allocated by malloc call.
+/// The Type depends on the number of bitcast uses of the malloc call:
+///   0: PointerType is the malloc calls' return type.
+///   1: PointerType is the bitcast's result type.
+///  >1: Unique PointerType cannot be determined, return NULL.
 const Type *llvm::getMallocAllocatedType(const CallInst *CI) {
   const PointerType *PT = getMallocType(CI);
   return PT ? PT->getElementType() : NULL;