mirror of
https://github.com/opnsense/src.git
synced 2026-04-04 08:55:18 -04:00
af366d353b
The C variant in libkern performs excessive branching to find the non-zero byte instead of using the bsfq instruction. The same code patched to use it is still slower than the routine implemented here as the compiler keeps neglecting to perform certain optimizations (like using leaq). On top of that the routine can is a starting point for copyinstr which operates on words instead of bytes. Tested with glibc test suite. Sample results (calls/s): Haswell: $(perl -e "print 'A' x 3"): stock: 211198039 patched:338626619 asm: 465609618 $(perl -e "print 'A' x 100"): stock: 83151997 patched: 98285919 asm: 120719888 AMD EPYC 7R32: $(perl -e "print 'A' x 3"): stock: 282523617 asm: 491498172 $(perl -e "print 'A' x 100"): stock: 114857172 asm: 112082057 |
||
|---|---|---|
| .. | ||
| acpica | ||
| amd64 | ||
| cloudabi32 | ||
| cloudabi64 | ||
| conf | ||
| ia32 | ||
| include | ||
| linux | ||
| linux32 | ||
| pci | ||
| sgx | ||
| vmm | ||
| Makefile | ||