musl - musl - an implementation of the standard library for Linux-based systems

math: fix x86_64 and x32 asm not to use sahf instruction

Some early x86_64 cpus (released before 2006) did not support sahf/lahf instructions so they should be avoided (intel manual says they are only supported if CPUID.80000001H:ECX.LAHF-SAHF[bit 0] = 1). The workaround simplifies exp2l and expm1l because fucomip can be used instead of the fucomp;fnstsw;sahf sequence copied from i386. In fmodl and remainderl sahf is replaced by a simple bit test.

Diffstat (limited to 'src/stdio')

0 files changed, 0 insertions, 0 deletions