math: add macros for static branch prediction hints
authorSzabolcs Nagy <nsz@port70.net>
Thu, 29 Nov 2018 23:33:40 +0000 (23:33 +0000)
committerRich Felker <dalias@aerifal.cx>
Wed, 17 Apr 2019 17:12:08 +0000 (13:12 -0400)
commit3c3763fc529114e209aea08336a420c5d5be4dc2
tree6ab36f16fb49fa0b92c433b5a9fe080237326f1a
parent4f8acf953ccf1a978a3378db7fb1e8d5a7afbca1
math: add macros for static branch prediction hints

These don't have an effectw with -Os so not useful with default settings
other than documenting the expectation.

With --enable-optimize=internal,malloc,string,math the libc.so code size
increases by 18K on x86_64 and performance varies in -2% .. +10%.
src/internal/libm.h