glibc/sysdeps/x86_64/multiarch/rawmemchr-evex-rtm.S

#define RAWMEMCHR	__rawmemchr_evex_rtm

#define USE_IN_RTM	1
#define SECTION(p)	p##.evex.rtm

#include "rawmemchr-evex.S"
x86: Optimize memchr-evex.S and implement with VMM headers Optimizations are: 1. Use the fact that tzcnt(0) -> VEC_SIZE for memchr to save a branch in short string case. 2. Restructure code so that small strings are given the hot path. - This is a net-zero on the benchmark suite but in general makes sense as smaller sizes are far more common. 3. Use more code-size efficient instructions. - tzcnt ... -> bsf ... - vpcmpb $0 ... -> vpcmpeq ... 4. Align labels less aggressively, especially if it doesn't save fetch blocks / causes the basic-block to span extra cache-lines. The optimizations (especially for point 2) make the memchr and rawmemchr code essentially incompatible so split rawmemchr-evex to a new file. Code Size Changes: memchr-evex.S : -107 bytes rawmemchr-evex.S : -53 bytes Net perf changes: Reported as geometric mean of all improvements / regressions from N=10 runs of the benchtests. Value as New Time / Old Time so < 1.0 is improvement and 1.0 is regression. memchr-evex.S : 0.928 rawmemchr-evex.S : 0.986 (Less targets cross cache lines) Full results attached in email. Full check passes on x86-64. 2022-10-19 00:44:03 +00:00			`#define RAWMEMCHR __rawmemchr_evex_rtm`

			`#define USE_IN_RTM 1`
			`#define SECTION(p) p##.evex.rtm`

			`#include "rawmemchr-evex.S"`