Commit Graph

3 Commits

Author SHA1 Message Date
Noah Goldstein
08cbcd4dbc x86: Remove unnecessary overflow check from wcsnlen-sse4_1.S
No bug. The way wcsnlen will check if near the end of maxlen
is the following macro:

	mov	%r11, %rsi;	\
	subq	%rax, %rsi;	\
	andq	$-64, %rax;	\
	testq	$-64, %rsi;	\
	je	L(strnlen_ret)

Which words independently of s + maxlen overflowing. So the
second overflow check is unnecissary for correctness and
just extra overhead in the common no overflow case.

test-strlen.c, test-wcslen.c, test-strnlen.c and test-wcsnlen.c are
all passing

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-06-24 19:14:19 -04:00
Noah Goldstein
a775a7a3eb x86: Fix overflow bug in wcsnlen-sse4_1 and wcsnlen-avx2 [BZ #27974]
This commit fixes the bug mentioned in the previous commit.

The previous implementations of wmemchr in these files relied
on maxlen * sizeof(wchar_t) which was not guranteed by the standard.

The new overflow tests added in the previous commit now
pass (As well as all the other tests).

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-06-23 14:13:06 -04:00
H.J. Lu
a0db678071 x86-64: Move strlen.S to multiarch/strlen-vec.S
Since strlen.S contains SSE2 version of strlen/strnlen and SSE4.1
version of wcslen/wcsnlen, move strlen.S to multiarch/strlen-vec.S
and include multiarch/strlen-vec.S from SSE2 and SSE4.1 variants.
This also removes the unused symbols, __GI___strlen_sse2 and
__GI___wcsnlen_sse4_1.
2021-06-23 10:24:35 -07:00