No bug.
The optimizations are as follows:
1) Always align entry to 64 bytes. This makes behavior more
predictable and makes other frontend optimizations easier.
2) Make the L(more_8x_vec) cases 4k aliasing aware. This can have
significant benefits in the case that:
0 < (dst - src) < [256, 512]
3) Align before `rep movsb`. For ERMS this is roughly a [0, 30%]
improvement and for FSRM [-10%, 25%].
In addition to these primary changes there is general cleanup
throughout to optimize the aligning routines and control flow logic.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
Since apply_irel is called before memcpy and mempcpy are called, we
can use IFUNC memcpy and mempcpy in libc.a.
* sysdeps/x86_64/memmove.S (MEMCPY_SYMBOL): Don't check SHARED.
(MEMPCPY_SYMBOL): Likewise.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Test memcpy and mempcpy in libc.a.
* sysdeps/x86_64/multiarch/memcpy-ssse3-back.S: Also include
in libc.a.
* sysdeps/x86_64/multiarch/memcpy-ssse3.S: Likewise.
* sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S:
Likewise.
* sysdeps/x86_64/multiarch/memcpy.c: Also include in libc.a.
(__hidden_ver1): Don't use in libc.a.
* sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S
(__mempcpy): Don't create a weak alias in libc.a.
* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Support
libc.a.
* sysdeps/x86_64/multiarch/mempcpy.c: Also include in libc.a.
(__hidden_ver1): Don't use in libc.a.
Since the new SSE2/AVX2 memcpy/memmove are faster than the previous ones,
we can remove the previous SSE2/AVX2 memcpy/memmove and replace them with
the new ones.
No change in IFUNC selection if SSE2 and AVX2 memcpy/memmove weren't used
before. If SSE2 or AVX2 memcpy/memmove were used, the new SSE2 or AVX2
memcpy/memmove optimized with Enhanced REP MOVSB will be used for
processors with ERMS. The new AVX512 memcpy/memmove will be used for
processors with AVX512 which prefer vzeroupper.
Since the new SSE2 memcpy/memmove are faster than the previous default
memcpy/memmove used in libc.a and ld.so, we also remove the previous
default memcpy/memmove and make them the default memcpy/memmove, except
that non-temporal store isn't used in ld.so.
Together, it reduces the size of libc.so by about 6 KB and the size of
ld.so by about 2 KB.
[BZ #19776]
* sysdeps/x86_64/memcpy.S: Make it dummy.
* sysdeps/x86_64/mempcpy.S: Likewise.
* sysdeps/x86_64/memmove.S: New file.
* sysdeps/x86_64/memmove_chk.S: Likewise.
* sysdeps/x86_64/multiarch/memmove.S: Likewise.
* sysdeps/x86_64/multiarch/memmove_chk.S: Likewise.
* sysdeps/x86_64/memmove.c: Removed.
* sysdeps/x86_64/multiarch/memcpy-avx-unaligned.S: Likewise.
* sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S: Likewise.
* sysdeps/x86_64/multiarch/memmove-avx-unaligned.S: Likewise.
* sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S:
Likewise.
* sysdeps/x86_64/multiarch/memmove.c: Likewise.
* sysdeps/x86_64/multiarch/memmove_chk.c: Likewise.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Remove
memcpy-sse2-unaligned, memmove-avx-unaligned,
memcpy-avx-unaligned and memmove-sse2-unaligned-erms.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Replace
__memmove_chk_avx512_unaligned_2 with
__memmove_chk_avx512_unaligned. Remove
__memmove_chk_avx_unaligned_2. Replace
__memmove_chk_sse2_unaligned_2 with
__memmove_chk_sse2_unaligned. Remove __memmove_chk_sse2 and
__memmove_avx_unaligned_2. Replace __memmove_avx512_unaligned_2
with __memmove_avx512_unaligned. Replace
__memmove_sse2_unaligned_2 with __memmove_sse2_unaligned.
Remove __memmove_sse2. Replace __memcpy_chk_avx512_unaligned_2
with __memcpy_chk_avx512_unaligned. Remove
__memcpy_chk_avx_unaligned_2. Replace
__memcpy_chk_sse2_unaligned_2 with __memcpy_chk_sse2_unaligned.
Remove __memcpy_chk_sse2. Remove __memcpy_avx_unaligned_2.
Replace __memcpy_avx512_unaligned_2 with
__memcpy_avx512_unaligned. Remove __memcpy_sse2_unaligned_2
and __memcpy_sse2. Replace __mempcpy_chk_avx512_unaligned_2
with __mempcpy_chk_avx512_unaligned. Remove
__mempcpy_chk_avx_unaligned_2. Replace
__mempcpy_chk_sse2_unaligned_2 with
__mempcpy_chk_sse2_unaligned. Remove __mempcpy_chk_sse2.
Replace __mempcpy_avx512_unaligned_2 with
__mempcpy_avx512_unaligned. Remove __mempcpy_avx_unaligned_2.
Replace __mempcpy_sse2_unaligned_2 with
__mempcpy_sse2_unaligned. Remove __mempcpy_sse2.
* sysdeps/x86_64/multiarch/memcpy.S (__new_memcpy): Support
__memcpy_avx512_unaligned_erms and __memcpy_avx512_unaligned.
Use __memcpy_avx_unaligned_erms and __memcpy_sse2_unaligned_erms
if processor has ERMS. Default to __memcpy_sse2_unaligned.
(ENTRY): Removed.
(END): Likewise.
(ENTRY_CHK): Likewise.
(libc_hidden_builtin_def): Likewise.
Don't include ../memcpy.S.
* sysdeps/x86_64/multiarch/memcpy_chk.S (__memcpy_chk): Support
__memcpy_chk_avx512_unaligned_erms and
__memcpy_chk_avx512_unaligned. Use
__memcpy_chk_avx_unaligned_erms and
__memcpy_chk_sse2_unaligned_erms if if processor has ERMS.
Default to __memcpy_chk_sse2_unaligned.
* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
Change function suffix from unaligned_2 to unaligned.
* sysdeps/x86_64/multiarch/mempcpy.S (__mempcpy): Support
__mempcpy_avx512_unaligned_erms and __mempcpy_avx512_unaligned.
Use __mempcpy_avx_unaligned_erms and __mempcpy_sse2_unaligned_erms
if processor has ERMS. Default to __mempcpy_sse2_unaligned.
(ENTRY): Removed.
(END): Likewise.
(ENTRY_CHK): Likewise.
(libc_hidden_builtin_def): Likewise.
Don't include ../mempcpy.S.
(mempcpy): New. Add a weak alias.
* sysdeps/x86_64/multiarch/mempcpy_chk.S (__mempcpy_chk): Support
__mempcpy_chk_avx512_unaligned_erms and
__mempcpy_chk_avx512_unaligned. Use
__mempcpy_chk_avx_unaligned_erms and
__mempcpy_chk_sse2_unaligned_erms if if processor has ERMS.
Default to __mempcpy_chk_sse2_unaligned.
