-// Check whether it is valid to call getCastOpcode for these types.
-// This routine must be kept in sync with getCastOpcode.
-bool CastInst::isCastable(Type *SrcTy, Type *DestTy) {
- if (!SrcTy->isFirstClassType() || !DestTy->isFirstClassType())
- return false;
-
- if (SrcTy == DestTy)
- return true;
-
- if (VectorType *SrcVecTy = dyn_cast<VectorType>(SrcTy))
- if (VectorType *DestVecTy = dyn_cast<VectorType>(DestTy))
- if (SrcVecTy->getNumElements() == DestVecTy->getNumElements()) {
- // An element by element cast. Valid if casting the elements is valid.
- SrcTy = SrcVecTy->getElementType();
- DestTy = DestVecTy->getElementType();
- }
-
- // Get the bit sizes, we'll need these
- unsigned SrcBits = SrcTy->getPrimitiveSizeInBits(); // 0 for ptr
- unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr
-
- // Run through the possibilities ...
- if (DestTy->isIntegerTy()) { // Casting to integral
- if (SrcTy->isIntegerTy()) { // Casting from integral
- return true;
- } else if (SrcTy->isFloatingPointTy()) { // Casting from floating pt
- return true;
- } else if (SrcTy->isVectorTy()) { // Casting from vector
- return DestBits == SrcBits;
- } else { // Casting from something else
- return SrcTy->isPointerTy();
- }
- } else if (DestTy->isFloatingPointTy()) { // Casting to floating pt
- if (SrcTy->isIntegerTy()) { // Casting from integral
- return true;
- } else if (SrcTy->isFloatingPointTy()) { // Casting from floating pt
- return true;
- } else if (SrcTy->isVectorTy()) { // Casting from vector
- return DestBits == SrcBits;
- } else { // Casting from something else
- return false;
- }
- } else if (DestTy->isVectorTy()) { // Casting to vector
- return DestBits == SrcBits;
- } else if (DestTy->isPointerTy()) { // Casting to pointer
- if (SrcTy->isPointerTy()) { // Casting from pointer
- return true;
- } else if (SrcTy->isIntegerTy()) { // Casting from integral
- return true;
- } else { // Casting from something else
- return false;
- }
- } else if (DestTy->isX86_MMXTy()) {
- if (SrcTy->isVectorTy()) {
- return DestBits == SrcBits; // 64-bit vector to MMX
- } else {
- return false;
- }
- } else { // Casting to something else
- return false;
- }
-}
-