8c9b6a88b7
The old version was oddly written to have the repeat count in multiple registers. So instead of taking advantage of %rax being zero, it had some sub-counts in it. All just for a "single word clearing" loop, which isn't even efficient to begin with. So get rid of those games, and just keep all the state in the same registers we got it in (and that we should return things in). That not only makes this act much more like 'rep stos' (which this function is replacing), but makes it much easier to actually do the obvious loop unrolling. Also rename the function from the now nonsensical 'clear_user_original' to what it now clearly is: 'rep_stos_alternative'. End result: if we don't have a fast 'rep stosb', at least we can have a fast fallback for it. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| Documentation | ||
| arch | ||
| include/objtool | ||
| .gitignore | ||
| Build | ||
| Makefile | ||
| builtin-check.c | ||
| check.c | ||
| elf.c | ||
| objtool.c | ||
| orc_dump.c | ||
| orc_gen.c | ||
| special.c | ||
| sync-check.sh | ||
| weak.c | ||