On Tue, 23 Jul 2019, Tejas Joshi wrote: > Also, CASE_MATHFN and CASE_MATHFN_FLOATN cases in builtins.c expand > normal, F and L variants which are assigned to respective fcode > built_in_function. This makes any function defined in builtins.def to > have F and L variants mandatory. How these narrowing functions are > supposed to be handled? Do we define another macro expansion like > CASE_MATHFN or have a manual case handling in mathfn_built_in_2? > Attached patch is what I have tried so far.
You'll need something different from CASE_MATHFN - these are a different kind of functions that need handling in a different way, because they are parametrized over certain *pairs* of types, rather than over a single type. (The main case for these being built-in is probably not folding for constant arguments - it's generating appropriate instructions when building with -fno-math-errno for processors that have appropriate narrowing instructions, such as Power ISA 2.07 or later, which I think means POWER8 or later.) -- Joseph S. Myers jos...@codesourcery.com
