Implement new cast creation functions for both instructions and constant

expressions. These will get used to reduce clutter as we replace various
calls to createInferredCast and getCast.

llvm-svn: 32191

2 files changed, 68 insertions, 2 deletions

diff --git a/llvm/lib/VMCore/Constants.cpp b/llvm/lib/VMCore/Constants.cpp
index 17a5eaeabf3..966108748b8 100644
--- a/llvm/lib/VMCore/Constants.cpp
+++ b/llvm/lib/VMCore/Constants.cpp
@@ -1534,6 +1534,24 @@ Constant *ConstantExpr::getCast(unsigned oc, Constant *C, const Type *Ty) {
   return 0;
 }
 
+Constant *ConstantExpr::getZExtOrBitCast(Constant *C, const Type *Ty) {
+  if (C->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return getCast(Instruction::BitCast, C, Ty);
+  return getCast(Instruction::ZExt, C, Ty);
+}
+
+Constant *ConstantExpr::getSExtOrBitCast(Constant *C, const Type *Ty) {
+  if (C->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return getCast(Instruction::BitCast, C, Ty);
+  return getCast(Instruction::SExt, C, Ty);
+}
+
+Constant *ConstantExpr::getTruncOrBitCast(Constant *C, const Type *Ty) {
+  if (C->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return getCast(Instruction::BitCast, C, Ty);
+  return getCast(Instruction::Trunc, C, Ty);
+}
+
 Constant *ConstantExpr::getTrunc(Constant *C, const Type *Ty) {
   assert(C->getType()->isInteger() && "Trunc operand must be integer");
   assert(Ty->isIntegral() && "Trunc produces only integral");
@@ -1616,14 +1634,14 @@ Constant *ConstantExpr::getBitCast(Constant *C, const Type *DstTy) {
   // can't cast pointers to anything but pointers.
   const Type *SrcTy = C->getType();
   assert((isa<PointerType>(SrcTy) == isa<PointerType>(DstTy)) &&
-         "Bitcast cannot cast pointer to non-pointer and vice versa");
+         "BitCast cannot cast pointer to non-pointer and vice versa");
 
   // Now we know we're not dealing with mismatched pointer casts (ptr->nonptr
   // or nonptr->ptr). For all the other types, the cast is okay if source and 
   // destination bit widths are identical.
   unsigned SrcBitSize = SrcTy->getPrimitiveSizeInBits();
   unsigned DstBitSize = DstTy->getPrimitiveSizeInBits();
-  assert(SrcBitSize == DstBitSize && "Bitcast requies types of same width");
+  assert(SrcBitSize == DstBitSize && "BitCast requies types of same width");
   return getFoldedCast(Instruction::BitCast, C, DstTy);
 }
 
diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index de1ebced7bc..8c1f47d8afb 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -1500,6 +1500,54 @@ CastInst *CastInst::create(Instruction::CastOps op, Value *S, const Type *Ty,
   return 0;
 }
 
+CastInst *CastInst::createZExtOrBitCast(Value *S, const Type *Ty, 
+                                        const std::string &Name,
+                                        Instruction *InsertBefore) {
+  if (S->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return create(Instruction::BitCast, S, Ty, Name, InsertBefore);
+  return create(Instruction::ZExt, S, Ty, Name, InsertBefore);
+}
+
+CastInst *CastInst::createZExtOrBitCast(Value *S, const Type *Ty, 
+                                        const std::string &Name,
+                                        BasicBlock *InsertAtEnd) {
+  if (S->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
+  return create(Instruction::ZExt, S, Ty, Name, InsertAtEnd);
+}
+
+CastInst *CastInst::createSExtOrBitCast(Value *S, const Type *Ty, 
+                                        const std::string &Name,
+                                        Instruction *InsertBefore) {
+  if (S->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return create(Instruction::BitCast, S, Ty, Name, InsertBefore);
+  return create(Instruction::SExt, S, Ty, Name, InsertBefore);
+}
+
+CastInst *CastInst::createSExtOrBitCast(Value *S, const Type *Ty, 
+                                        const std::string &Name,
+                                        BasicBlock *InsertAtEnd) {
+  if (S->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
+  return create(Instruction::SExt, S, Ty, Name, InsertAtEnd);
+}
+
+CastInst *CastInst::createTruncOrBitCast(Value *S, const Type *Ty,
+                                         const std::string &Name,
+                                         Instruction *InsertBefore) {
+  if (S->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return create(Instruction::BitCast, S, Ty, Name, InsertBefore);
+  return create(Instruction::Trunc, S, Ty, Name, InsertBefore);
+}
+
+CastInst *CastInst::createTruncOrBitCast(Value *S, const Type *Ty,
+                                         const std::string &Name, 
+                                         BasicBlock *InsertAtEnd) {
+  if (S->getType()->getPrimitiveSizeInBits() == Ty->getPrimitiveSizeInBits())
+    return create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
+  return create(Instruction::Trunc, S, Ty, Name, InsertAtEnd);
+}
+
 // Provide a way to get a "cast" where the cast opcode is inferred from the 
 // types and size of the operand. This, basically, is a parallel of the 
 // logic in the checkCast function below.  This axiom should hold: