Prior to this patch FixedPointSemantics and APFixedPoint only support semantics where
the Scale larger or equal to zero and the Width is larger or equal to the Scale.
This patch removes both those requirements while staying API compatible.
Due to how operator== changed after operator<=> landing in C++20
(error: use of overloaded operator '==' is ambiguous (with operand
types 'const llvm::APSInt' and 'const unsigned long')),
CheckIntPartMin/CheckIntPartMax interfaces are now leveraging
APSInt::compareValues.
Differential Revision: https://reviews.llvm.org/D129567
This patch moves FixedPointSemantics and APFixedPoint
from Clang to LLVM ADT.
This will make it easier to use the fixed-point
classes in LLVM for constructing an IR builder for
fixed-point and for reusing the APFixedPoint class
for constant evaluation purposes.
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-August/144025.html
Reviewed By: leonardchan, rjmccall
Differential Revision: https://reviews.llvm.org/D85312
