+
+//===----------------------------------------------------------------------===//
+// AttributeFuncs Function Defintions
+//===----------------------------------------------------------------------===//
+
+Attribute AttributeFuncs::typeIncompatible(Type *Ty) {
+ AttrBuilder Incompatible;
+
+ if (!Ty->isIntegerTy())
+ // Attribute that only apply to integers.
+ Incompatible.addAttribute(Attribute::SExt)
+ .addAttribute(Attribute::ZExt);
+
+ if (!Ty->isPointerTy())
+ // Attribute that only apply to pointers.
+ Incompatible.addAttribute(Attribute::ByVal)
+ .addAttribute(Attribute::Nest)
+ .addAttribute(Attribute::NoAlias)
+ .addAttribute(Attribute::NoCapture)
+ .addAttribute(Attribute::StructRet);
+
+ return Attribute::get(Ty->getContext(), Incompatible);
+}
+
+/// encodeLLVMAttributesForBitcode - This returns an integer containing an
+/// encoding of all the LLVM attributes found in the given attribute bitset.
+/// Any change to this encoding is a breaking change to bitcode compatibility.
+uint64_t AttributeFuncs::encodeLLVMAttributesForBitcode(AttributeSet Attrs,
+ unsigned Index) {
+ // FIXME: It doesn't make sense to store the alignment information as an
+ // expanded out value, we should store it as a log2 value. However, we can't
+ // just change that here without breaking bitcode compatibility. If this ever
+ // becomes a problem in practice, we should introduce new tag numbers in the
+ // bitcode file and have those tags use a more efficiently encoded alignment
+ // field.
+
+ // Store the alignment in the bitcode as a 16-bit raw value instead of a 5-bit
+ // log2 encoded value. Shift the bits above the alignment up by 11 bits.
+ uint64_t EncodedAttrs = Attrs.Raw(Index) & 0xffff;
+ if (Attrs.hasAttribute(Index, Attribute::Alignment))
+ EncodedAttrs |= Attrs.getParamAlignment(Index) << 16;
+ EncodedAttrs |= (Attrs.Raw(Index) & (0xffffULL << 21)) << 11;
+ return EncodedAttrs;
+}
+
+/// decodeLLVMAttributesForBitcode - This returns an attribute bitset containing
+/// the LLVM attributes that have been decoded from the given integer. This
+/// function must stay in sync with 'encodeLLVMAttributesForBitcode'.
+Attribute AttributeFuncs::decodeLLVMAttributesForBitcode(LLVMContext &C,
+ uint64_t EncodedAttrs){
+ // The alignment is stored as a 16-bit raw value from bits 31--16. We shift
+ // the bits above 31 down by 11 bits.
+ unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
+ assert((!Alignment || isPowerOf2_32(Alignment)) &&
+ "Alignment must be a power of two.");
+
+ AttrBuilder B(EncodedAttrs & 0xffff);
+ if (Alignment)
+ B.addAlignmentAttr(Alignment);
+ B.addRawValue((EncodedAttrs & (0xffffULL << 32)) >> 11);
+ return Attribute::get(C, B);
+}
+