[Bug libgcc/114131] New: std::isinf(std::float128_t) generates superfluous nan-checks

[g.peterhoff--- via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114131

            Bug ID: 114131
           Summary: std::isinf(std::float128_t) generates superfluous
                    nan-checks
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcc
          Assignee: unassigned at gcc dot gnu.org
          Reporter: g.peterh...@t-online.de
  Target Milestone: ---

please see https://godbolt.org/z/djc9q1vcv
test1(default): includes nan-checks (__unordtf2)
test2: no nan-checks, but calls __eqtf2
test3: only checks for inf (via bit_cast); no additional function calls +
branchfree. Of course, this only works if (unsigned) __int128 is available.

thx
Gero