Alpha and sparc can now use the generic implementation.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit b57ab258c1)
On i386 and ia64, the TCB is not available at this point.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit a2a6bce7d7)
And keep the previous definition if it exists. This allows
disabling IA64_USE_NEW_STUB while keeping USE_DL_SYSINFO defined.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 18bd9c3d3b)
Unlike MMAP_CALL, this avoids a TCB dependency for an errno update
on failure.
<mmap_internal.h> cannot be included as is on several architectures
due to the definition of page_unit, so introduce a separate header
file for the definition of MMAP_CALL and MMAP_CALL_INTERNAL,
<mmap_call.h>.
Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
(cherry picked from commit c1b68685d4)
Introduce an int-80h-based version of __libc_do_syscall and use
it if I386_USE_SYSENTER is defined as 0.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 60f0f2130d)
After commit a78e6a10d0
("i386: Remove broken CAN_USE_REGISTER_ASM_EBP (bug 28771)"),
it is never defined.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 6e5c7a1e26)
After 73fc4e28b9,
__libc_enable_secure_decided is always 0 and a statically linked
executable may overwrite __libc_enable_secure without considering
AT_SECURE.
The __libc_enable_secure has been correctly initialized in _dl_aux_init,
so just remove __libc_enable_secure_decided and __libc_init_secure.
This allows us to remove some startup_get*id functions from
22b79ed7f4.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 3e9acce8c5)
And optimize it slightly.
This is commit 8c8510ab27 revised.
In _dl_aux_init in elf/dl-support.c, use an explicit loop
and -fno-tree-loop-distribute-patterns to avoid memset.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
(cherry picked from commit 73fc4e28b9)
Otherwise, <dl-auxv.h> on POWER ends up being included twice,
once in dl-sysdep.c, once in dl-support.c. That leads to a linker
failure due to multiple definitions of _dl_cache_line_size.
Fixes commit d96d2995c1
("Revert "Linux: Consolidate auxiliary vector parsing").
(cherry picked from commit 098c795e85)
This reverts commit 8c8510ab27. The
revert is not perfect because the commit included a bug fix for
_dl_sysdep_start with an empty argv, introduced in commit
2d47fa6862 ("Linux: Remove
DL_FIND_ARG_COMPONENTS"), and this bug fix is kept.
The revert is necessary because the reverted commit introduced an
early memset call on aarch64, which leads to crash due to lack of TCB
initialization.
(cherry picked from commit d96d2995c1)
And optimize it slightly.
The large switch statement in _dl_sysdep_start can be replaced with
a large array. This reduces source code and binary size. On
i686-linux-gnu:
Before:
text data bss dec hex filename
7791 12 0 7803 1e7b elf/dl-sysdep.os
After:
text data bss dec hex filename
7135 12 0 7147 1beb elf/dl-sysdep.os
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 8c8510ab27)
The definition itself is still needed for generic code.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit f19fc997a5)
The generic definition is always used since the Native Client
port has been removed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 2d47fa6862)
The generic version is the de-facto Linux implementation. It
requires an auxiliary vector, so Hurd does not use it.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 91c0a47ffb)
The new code unrolls the main loop slightly without adding too much
overhead and minimizes the comparisons for the search CHAR.
Geometric Mean of all benchmarks New / Old: 0.755
See email for all results.
Full xcheck passes on x86_64 with and without multiarch enabled.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit c966099cdc)
The new code unrolls the main loop slightly without adding too much
overhead and minimizes the comparisons for the search CHAR.
Geometric Mean of all benchmarks New / Old: 0.832
See email for all results.
Full xcheck passes on x86_64 with and without multiarch enabled.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit df7e295d18)
The new code unrolls the main loop slightly without adding too much
overhead and minimizes the comparisons for the search CHAR.
Geometric Mean of all benchmarks New / Old: 0.741
See email for all results.
Full xcheck passes on x86_64 with and without multiarch enabled.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 5307aa9c18)
Code didn't actually use any sse4 instructions since `ptest` was
removed in:
commit 2f9062d717
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Wed Nov 10 16:18:56 2021 -0600
x86: Shrink memcmp-sse4.S code size
The new memcmp-sse2 implementation is also faster.
geometric_mean(N=20) of page cross cases SSE2 / SSE4: 0.905
Note there are two regressions preferring SSE2 for Size = 1 and Size =
65.
Size = 1:
size, align0, align1, ret, New Time/Old Time
1, 1, 1, 0, 1.2
1, 1, 1, 1, 1.197
1, 1, 1, -1, 1.2
This is intentional. Size == 1 is significantly less hot based on
profiles of GCC11 and Python3 than sizes [4, 8] (which is made
hotter).
Python3 Size = 1 -> 13.64%
Python3 Size = [4, 8] -> 60.92%
GCC11 Size = 1 -> 1.29%
GCC11 Size = [4, 8] -> 33.86%
size, align0, align1, ret, New Time/Old Time
4, 4, 4, 0, 0.622
4, 4, 4, 1, 0.797
4, 4, 4, -1, 0.805
5, 5, 5, 0, 0.623
5, 5, 5, 1, 0.777
5, 5, 5, -1, 0.802
6, 6, 6, 0, 0.625
6, 6, 6, 1, 0.813
6, 6, 6, -1, 0.788
7, 7, 7, 0, 0.625
7, 7, 7, 1, 0.799
7, 7, 7, -1, 0.795
8, 8, 8, 0, 0.625
8, 8, 8, 1, 0.848
8, 8, 8, -1, 0.914
9, 9, 9, 0, 0.625
Size = 65:
size, align0, align1, ret, New Time/Old Time
65, 0, 0, 0, 1.103
65, 0, 0, 1, 1.216
65, 0, 0, -1, 1.227
65, 65, 0, 0, 1.091
65, 0, 65, 1, 1.19
65, 65, 65, -1, 1.215
This is because A) the checks in range [65, 96] are now unrolled 2x
and B) because smaller values <= 16 are now given a hotter path. By
contrast the SSE4 version has a branch for Size = 80. The unrolled
version has get better performance for returns which need both
comparisons.
size, align0, align1, ret, New Time/Old Time
128, 4, 8, 0, 0.858
128, 4, 8, 1, 0.879
128, 4, 8, -1, 0.888
As well, out of microbenchmark environments that are not full
predictable the branch will have a real-cost.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 7cbc03d030)
Just a few QOL changes.
1. Prefer `add` > `lea` as it has high execution units it can run
on.
2. Don't break macro-fusion between `test` and `jcc`
3. Reduce code size by removing gratuitous padding bytes (-90
bytes).
geometric_mean(N=20) of all benchmarks New / Original: 0.959
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 244b415d38)
The rational is:
1. SSE42 has nearly identical logic so any benefit is minimal (3.4%
regression on Tigerlake using SSE42 versus AVX across the
benchtest suite).
2. AVX2 version covers the majority of targets that previously
prefered it.
3. The targets where AVX would still be best (SnB and IVB) are
becoming outdated.
All in all the saving the code size is worth it.
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 305769b2a1)
geometric_mean(N=40) of all benchmarks EVEX / SSE42: .621
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 84e7c46df4)
geometric_mean(N=40) of all benchmarks AVX2 / SSE42: .702
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit bbf8122234)
Slightly faster method of doing TOLOWER that saves an
instruction.
Also replace the hard coded 5-byte no with .p2align 4. On builds with
CET enabled this misaligned entry to strcasecmp.
geometric_mean(N=40) of all benchmarks New / Original: .920
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit d154758e61)
Slightly faster method of doing TOLOWER that saves an
instruction.
Also replace the hard coded 5-byte no with .p2align 4. On builds with
CET enabled this misaligned entry to strcasecmp.
geometric_mean(N=40) of all benchmarks New / Original: .894
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 670b54bc58)
The generic implementation is faster.
geometric_mean(N=20) of all benchmarks New / Original: .710
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 9c8a6ad620)
The generic implementation is faster (see strcspn commit).
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 6533585352)
The generic implementation is faster.
geometric_mean(N=20) of all benchmarks New / Original: .678
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit fe28e7d9d9)
Use _mm_cmpeq_epi8 and _mm_movemask_epi8 to get strlen instead of
_mm_cmpistri. Also change offset to unsigned to avoid unnecessary
sign extensions.
geometric_mean(N=20) of all benchmarks that dont fallback on
sse2; New / Original: .901
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 412d103431)
Use _mm_cmpeq_epi8 and _mm_movemask_epi8 to get strlen instead of
_mm_cmpistri. Also change offset to unsigned to avoid unnecessary
sign extensions.
geometric_mean(N=20) of all benchmarks that dont fallback on
sse2/strlen; New / Original: .928
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 30d627d477)
Small code cleanup for size: -81 bytes.
Add comment justifying using a branch to do NULL/non-null return.
All string/memory tests pass and no regressions in benchtests.
geometric_mean(N=20) of all benchmarks New / Original: .985
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit ec285ea904)
Small code cleanup for size: -53 bytes.
Add comment justifying using a branch to do NULL/non-null return.
All string/memory tests pass and no regressions in benchtests.
geometric_mean(N=20) of all benchmarks Original / New: 1.00
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit a6fbf4d51e)
commit 3d9f171bfb
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Feb 7 05:55:15 2022 -0800
x86-64: Optimize bzero
added the optimized bzero. Remove bzero weak alias in SS2 memset to
avoid undefined __bzero in memset-sse2-unaligned-erms.
(cherry picked from commit 0fb8800029)
Overflow case for __wcsncmp_avx2_rtm should be __wcscmp_avx2_rtm not
__wcscmp_avx2.
commit ddf0992cf5
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Sun Jan 9 16:02:21 2022 -0600
x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755]
Set the wrong fallback function for `__wcsncmp_avx2_rtm`. It was set
to fallback on to `__wcscmp_avx2` instead of `__wcscmp_avx2_rtm` which
can cause spurious aborts.
This change will need to be backported.
All string/memory tests pass.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit 9fef7039a7)
Logic can read before the start of `s1` / `s2` if both `s1` and `s2`
are near the start of a page. To avoid having the result contimated by
these comparisons the `strcmp` variants would mask off these
comparisons. This was missing in the `strncmp` variants causing
the bug. This commit adds the masking to `strncmp` so that out of
range comparisons don't affect the result.
test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass as
well a full xcheck on x86_64 linux.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit e108c02a5e)
commit 3d9f171bfb
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Feb 7 05:55:15 2022 -0800
x86-64: Optimize bzero
Remove setting the .text section for the code. This commit
adds that back.
(cherry picked from commit 7912236f4a)
memset with zero as the value to set is by far the majority value (99%+
for Python3 and GCC).
bzero can be slightly more optimized for this case by using a zero-idiom
xor for broadcasting the set value to a register (vector or GPR).
Co-developed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 3d9f171bfb)
commit b62ace2740
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Sun Feb 6 00:54:18 2022 -0600
x86: Improve vec generation in memset-vec-unaligned-erms.S
Revert usage of 'pshufb' in broadcast logic as it is an SSSE3
instruction and memset.S is restricted to only SSE2 instructions.
(cherry picked from commit 1b0c60f95b)
No bug.
Split vec generation into multiple steps. This allows the
broadcast in AVX2 to use 'xmm' registers for the L(less_vec)
case. This saves an expensive lane-cross instruction and removes
the need for 'vzeroupper'.
For SSE2 replace 2x 'punpck' instructions with zero-idiom 'pxor' for
byte broadcast.
Results for memset-avx2 small (geomean of N = 20 benchset runs).
size, New Time, Old Time, New / Old
0, 4.100, 3.831, 0.934
1, 5.074, 4.399, 0.867
2, 4.433, 4.411, 0.995
4, 4.487, 4.415, 0.984
8, 4.454, 4.396, 0.987
16, 4.502, 4.443, 0.987
All relevant string/wcsmbs tests are passing.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit b62ace2740)
Optimization are primarily to the loop logic and how the page cross
logic interacts with the loop.
The page cross logic is at times more expensive for short strings near
the end of a page but not crossing the page. This is done to retest
the page cross conditions with a non-faulty check and to improve the
logic for entering the loop afterwards. This is only particular cases,
however, and is general made up for by more than 10x improvements on
the transition from the page cross -> loop case.
The non-page cross cases as well are nearly universally improved.
test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 8418eb3ff4)
Optimization are primarily to the loop logic and how the page cross
logic interacts with the loop.
The page cross logic is at times more expensive for short strings near
the end of a page but not crossing the page. This is done to retest
the page cross conditions with a non-faulty check and to improve the
logic for entering the loop afterwards. This is only particular cases,
however, and is general made up for by more than 10x improvements on
the transition from the page cross -> loop case.
The non-page cross cases are improved most for smaller sizes [0, 128]
and go about even for (128, 4096]. The loop page cross logic is
improved so some more significant speedup is seen there as well.
test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit b77b06e0e2)
Add the new HWCAP2_AFP and HWCAP2_RPRES constants from Linux 5.17.
Tested with build-many-glibcs.py for aarch64-linux-gnu.
(cherry picked from commit 866c599182)
Indicates the availability of enhanced counter virtualization extension
of armv8.6-a with self-synchronized virtual counter CNTVCTSS_EL0 usable
in userspace.
(cherry picked from commit 5a1be8ebdf)
Linux 5.16 adds constants SOL_MPTCP and SOL_MCTP to the getsockopt /
setsockopt levels; add these constants to bits/socket.h.
Tested for x86_64.
(cherry picked from commit fdc1ae67fe)