Split the logic behind CastInst::isNoopCast into a separate static function,
as is done with most other cast opcode predicates.
llvm-svn: 105008
diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index 3060a76..76bf583 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -1911,9 +1911,12 @@
/// # bitcast i32* %x to i8*
/// # bitcast <2 x i32> %x to <4 x i16>
/// # ptrtoint i32* %x to i32 ; on 32-bit plaforms only
-/// @brief Determine if a cast is a no-op.
-bool CastInst::isNoopCast(const Type *IntPtrTy) const {
- switch (getOpcode()) {
+/// @brief Determine if the described cast is a no-op.
+bool CastInst::isNoopCast(Instruction::CastOps Opcode,
+ const Type *SrcTy,
+ const Type *DestTy,
+ const Type *IntPtrTy) {
+ switch (Opcode) {
default:
assert(!"Invalid CastOp");
case Instruction::Trunc:
@@ -1930,13 +1933,18 @@
return true; // BitCast never modifies bits.
case Instruction::PtrToInt:
return IntPtrTy->getScalarSizeInBits() ==
- getType()->getScalarSizeInBits();
+ DestTy->getScalarSizeInBits();
case Instruction::IntToPtr:
return IntPtrTy->getScalarSizeInBits() ==
- getOperand(0)->getType()->getScalarSizeInBits();
+ SrcTy->getScalarSizeInBits();
}
}
+/// @brief Determine if a cast is a no-op.
+bool CastInst::isNoopCast(const Type *IntPtrTy) const {
+ return isNoopCast(getOpcode(), getOperand(0)->getType(), getType(), IntPtrTy);
+}
+
/// This function determines if a pair of casts can be eliminated and what
/// opcode should be used in the elimination. This assumes that there are two
/// instructions like this: