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* x86_64: Add avx2 optimized __memcmpeq in memcmpeq-avx2.SNoah Goldstein2021-10-274-9/+308
| | | | | | | | | | | | | No bug. This commit adds new optimized __memcmpeq implementation for avx2. The primary optimizations are: 1) skipping the logic to find the difference of the first mismatched byte. 2) not updating src/dst addresses as the non-equals logic does not need to be reused by different areas.
* x86_64: Add support for __memcmpeq using sse2, avx2, and evexNoah Goldstein2021-10-2710-4/+193
| | | | | | No bug. This commit adds support for __memcmpeq to be implemented seperately from memcmp. Support is added for versions optimized with sse2, avx2, and evex.
* String: Add hidden defs for __memcmpeq() to enable internal usageNoah Goldstein2021-10-262-0/+4
| | | | | | | | No bug. This commit adds hidden defs for all declarations of __memcmpeq. This enables usage of __memcmpeq without the PLT for usage internal to GLIBC.
* String: Add support for __memcmpeq() ABI on all targetsNoah Goldstein2021-10-262-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | No bug. This commit adds support for __memcmpeq() as a new ABI for all targets. In this commit __memcmpeq() is implemented only as an alias to the corresponding targets memcmp() implementation. __memcmpeq() is added as a new symbol starting with GLIBC_2.35 and defined in string.h with comments explaining its behavior. Basic tests that it is callable and works where added in string/tester.c As discussed in the proposal "Add new ABI '__memcmpeq()' to libc" __memcmpeq() is essentially a reserved namespace for bcmp(). The means is shares the same specifications as memcmp() except the return value for non-equal byte sequences is any non-zero value. This is less strict than memcmp()'s return value specification and can be better optimized when a boolean return is all that is needed. __memcmpeq() is meant to only be called by compilers if they can prove that the return value of a memcmp() call is only used for its boolean value. All tests in string/tester.c passed. As well build succeeds on x86_64-linux-gnu target.
* x86: Replace sse2 instructions with avx in memcmp-evex-movbe.SNoah Goldstein2021-10-231-2/+2
| | | | | | | | | | | | | | This commit replaces two usages of SSE2 'movups' with AVX 'vmovdqu'. it could potentially be dangerous to use SSE2 if this function is ever called without using 'vzeroupper' beforehand. While compilers appear to use 'vzeroupper' before function calls if AVX2 has been used, using SSE2 here is more brittle. Since it is not absolutely necessary it should be avoided. It costs 2-extra bytes but the extra bytes should only eat into alignment padding. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Optimize memset-vec-unaligned-erms.SNoah Goldstein2021-10-124-91/+226
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No bug. Optimization are 1. change control flow for L(more_2x_vec) to fall through to loop and jump for L(less_4x_vec) and L(less_8x_vec). This uses less code size and saves jumps for length > 4x VEC_SIZE. 2. For EVEX/AVX512 move L(less_vec) closer to entry. 3. Avoid complex address mode for length > 2x VEC_SIZE 4. Slightly better aligning code for the loop from the perspective of code size and uops. 5. Align targets so they make full use of their fetch block and if possible cache line. 6. Try and reduce total number of icache lines that will need to be pulled in for a given length. 7. Include "local" version of stosb target. For AVX2/EVEX/AVX512 jumping to the stosb target in the sse2 code section will almost certainly be to a new page. The new version does increase code size marginally by duplicating the target but should get better iTLB behavior as a result. test-memset, test-wmemset, and test-bzero are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Optimize memcmp-evex-movbe.S for frontend behavior and sizeNoah Goldstein2021-10-121-192/+242
| | | | | | | | | | | | | | | | | | | | | | | | | | No bug. The frontend optimizations are to: 1. Reorganize logically connected basic blocks so they are either in the same cache line or adjacent cache lines. 2. Avoid cases when basic blocks unnecissarily cross cache lines. 3. Try and 32 byte align any basic blocks possible without sacrificing code size. Smaller / Less hot basic blocks are used for this. Overall code size shrunk by 168 bytes. This should make up for any extra costs due to aligning to 64 bytes. In general performance before deviated a great deal dependending on whether entry alignment % 64 was 0, 16, 32, or 48. These changes essentially make it so that the current implementation is at least equal to the best alignment of the original for any arguments. The only additional optimization is in the page cross case. Branch on equals case was removed from the size == [4, 7] case. As well the [4, 7] and [2, 3] case where swapped as [4, 7] is likely a more hot argument size. test-memcmp and test-wmemcmp are both passing.
* Remove "Contributed by" linesSiddhesh Poyarekar2021-09-0315-15/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* x86-64: Use testl to check __x86_string_controlH.J. Lu2021-08-301-2/+2
| | | | | | | Use testl, instead of andl, to check __x86_string_control to avoid updating __x86_string_control. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* x86-64: Add Avoid_Short_Distance_REP_MOVSBH.J. Lu2021-07-281-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | commit 3ec5d83d2a237d39e7fd6ef7a0bc8ac4c171a4a5 Author: H.J. Lu <hjl.tools@gmail.com> Date: Sat Jan 25 14:19:40 2020 -0800 x86-64: Avoid rep movsb with short distance [BZ #27130] introduced some regressions on Intel processors without Fast Short REP MOV (FSRM). Add Avoid_Short_Distance_REP_MOVSB to avoid rep movsb with short distance only on Intel processors with FSRM. bench-memmove-large on Skylake server shows that cycles of __memmove_evex_unaligned_erms improves for the following data size: before after Improvement length=4127, align1=3, align2=0: 479.38 349.25 27% length=4223, align1=9, align2=5: 405.62 333.25 18% length=8223, align1=3, align2=0: 786.12 496.38 37% length=8319, align1=9, align2=5: 727.50 501.38 31% length=16415, align1=3, align2=0: 1436.88 840.00 41% length=16511, align1=9, align2=5: 1375.50 836.38 39% length=32799, align1=3, align2=0: 2890.00 1860.12 36% length=32895, align1=9, align2=5: 2891.38 1931.88 33%
* x86: Remove wcsnlen-sse4_1 from wcslen ifunc-impl-list [BZ #28064]Noah Goldstein2021-07-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | The following commit commit 6f573a27b6c8b4236445810a44660612323f5a73 Author: Noah Goldstein <goldstein.w.n@gmail.com> Date: Wed Jun 23 01:19:34 2021 -0400 x86-64: Add wcslen optimize for sse4.1 Added wcsnlen-sse4.1 to the wcslen ifunc implementation list and did not add wcslen-sse4.1 to wcslen ifunc implementation list. This commit fixes that by removing wcsnlen-sse4.1 from the wcslen ifunc implementation list and adding wcslen-sse4.1 to the ifunc implementation list. Testing: test-wcslen.c, test-rsi-wcslen.c, and test-rsi-strlen.c are passing as well as all other tests in wcsmbs and string. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Remove unnecessary overflow check from wcsnlen-sse4_1.SNoah Goldstein2021-06-241-7/+0
| | | | | | | | | | | | | | | | | | | | | 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>
* x86: Fix overflow bug in wcsnlen-sse4_1 and wcsnlen-avx2 [BZ #27974]Noah Goldstein2021-06-232-38/+107
| | | | | | | | | | | | | 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>
* x86: Fix overflow bug with wmemchr-sse2 and wmemchr-avx2 [BZ #27974]Noah Goldstein2021-06-231-18/+40
| | | | | | | | | | | | | This commit fixes the bug mentioned in the previous commit. The previous implementations of wmemchr in these files relied on n * 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>
* x86-64: Add wcslen optimize for sse4.1Noah Goldstein2021-06-236-36/+63
| | | | | | | | | No bug. This comment adds the ifunc / build infrastructure necessary for wcslen to prefer the sse4.1 implementation in strlen-vec.S. test-wcslen.c is passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86-64: Move strlen.S to multiarch/strlen-vec.SH.J. Lu2021-06-233-2/+259
| | | | | | | | 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.
* x86: Improve memmove-vec-unaligned-erms.SNoah Goldstein2021-05-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the condition for copy 4x VEC so that if length is exactly equal to 4 * VEC_SIZE it will use the 4x VEC case instead of 8x VEC case. Results For Skylake memcpy-avx2-erms size, al1 , al2 , Cur T , New T , Win , New / Cur 128 , 0 , 0 , 9.137 , 6.873 , New , 75.22 128 , 7 , 0 , 12.933 , 7.732 , New , 59.79 128 , 0 , 7 , 11.852 , 6.76 , New , 57.04 128 , 7 , 7 , 12.587 , 6.808 , New , 54.09 Results For Icelake memcpy-evex-erms size, al1 , al2 , Cur T , New T , Win , New / Cur 128 , 0 , 0 , 9.963 , 5.416 , New , 54.36 128 , 7 , 0 , 16.467 , 8.061 , New , 48.95 128 , 0 , 7 , 14.388 , 7.644 , New , 53.13 128 , 7 , 7 , 14.546 , 7.642 , New , 52.54 Results For Tigerlake memcpy-evex-erms size, al1 , al2 , Cur T , New T , Win , New / Cur 128 , 0 , 0 , 8.979 , 4.95 , New , 55.13 128 , 7 , 0 , 14.245 , 7.122 , New , 50.0 128 , 0 , 7 , 12.668 , 6.675 , New , 52.69 128 , 7 , 7 , 13.042 , 6.802 , New , 52.15 Results For Skylake memmove-avx2-erms size, al1 , al2 , Cur T , New T , Win , New / Cur 128 , 0 , 32 , 6.181 , 5.691 , New , 92.07 128 , 32 , 0 , 6.165 , 5.752 , New , 93.3 128 , 0 , 7 , 13.923 , 9.37 , New , 67.3 128 , 7 , 0 , 12.049 , 10.182 , New , 84.5 Results For Icelake memmove-evex-erms size, al1 , al2 , Cur T , New T , Win , New / Cur 128 , 0 , 32 , 5.479 , 4.889 , New , 89.23 128 , 32 , 0 , 5.127 , 4.911 , New , 95.79 128 , 0 , 7 , 18.885 , 13.547 , New , 71.73 128 , 7 , 0 , 15.565 , 14.436 , New , 92.75 Results For Tigerlake memmove-evex-erms size, al1 , al2 , Cur T , New T , Win , New / Cur 128 , 0 , 32 , 5.275 , 4.815 , New , 91.28 128 , 32 , 0 , 5.376 , 4.565 , New , 84.91 128 , 0 , 7 , 19.426 , 14.273 , New , 73.47 128 , 7 , 0 , 15.924 , 14.951 , New , 93.89 Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86: Improve memset-vec-unaligned-erms.SNoah Goldstein2021-05-201-22/+28
| | | | | | | | | | | | | | | No bug. This commit makes a few small improvements to memset-vec-unaligned-erms.S. The changes are 1) only aligning to 64 instead of 128. Either alignment will perform equally well in a loop and 128 just increases the odds of having to do an extra iteration which can be significant overhead for small values. 2) Align some targets and the loop. 3) Remove an ALU from the alignment process. 4) Reorder the last 4x VEC so that they are stored after the loop. 5) Move the condition for leq 8x VEC to before the alignment process. test-memset and test-wmemset are both passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Optimize memcmp-evex-movbe.SNoah Goldstein2021-05-181-302/+408
| | | | | | | | | | | | No bug. This commit optimizes memcmp-evex.S. The optimizations include adding a new vec compare path for small sizes, reorganizing the entry control flow, removing some unnecissary ALU instructions from the main loop, and most importantly replacing the heavy use of vpcmp + kand logic with vpxor + vptern. test-memcmp and test-wmemcmp are both passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Optimize memcmp-avx2-movbe.SNoah Goldstein2021-05-183-281/+402
| | | | | | | | | | No bug. This commit optimizes memcmp-avx2.S. The optimizations include adding a new vec compare path for small sizes, reorganizing the entry control flow, and removing some unnecissary ALU instructions from the main loop. test-memcmp and test-wmemcmp are both passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Add EVEX optimized memchr family not safe for RTMNoah Goldstein2021-05-0810-41/+217
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No bug. This commit adds a new implementation for EVEX memchr that is not safe for RTM because it uses vzeroupper. The benefit is that by using ymm0-ymm15 it can use vpcmpeq and vpternlogd in the 4x loop which is faster than the RTM safe version which cannot use vpcmpeq because there is no EVEX encoding for the instruction. All parts of the implementation aside from the 4x loop are the same for the two versions and the optimization is only relevant for large sizes. Tigerlake: size , algn , Pos , Cur T , New T , Win , Dif 512 , 6 , 192 , 9.2 , 9.04 , no-RTM , 0.16 512 , 7 , 224 , 9.19 , 8.98 , no-RTM , 0.21 2048 , 0 , 256 , 10.74 , 10.54 , no-RTM , 0.2 2048 , 0 , 512 , 14.81 , 14.87 , RTM , 0.06 2048 , 0 , 1024 , 22.97 , 22.57 , no-RTM , 0.4 2048 , 0 , 2048 , 37.49 , 34.51 , no-RTM , 2.98 <-- Icelake: size , algn , Pos , Cur T , New T , Win , Dif 512 , 6 , 192 , 7.6 , 7.3 , no-RTM , 0.3 512 , 7 , 224 , 7.63 , 7.27 , no-RTM , 0.36 2048 , 0 , 256 , 8.48 , 8.38 , no-RTM , 0.1 2048 , 0 , 512 , 11.57 , 11.42 , no-RTM , 0.15 2048 , 0 , 1024 , 17.92 , 17.38 , no-RTM , 0.54 2048 , 0 , 2048 , 30.37 , 27.34 , no-RTM , 3.03 <-- test-memchr, test-wmemchr, and test-rawmemchr are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86-64: Fix an unknown vector operation in memchr-evex.SAlice Xu2021-05-071-1/+1
| | | | | | | An unknown vector operation occurred in commit 2a76821c308. Fixed it by using "ymm{k1}{z}" but not "ymm {k1} {z}". Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* Remove architecture specific sched_cpucount optimizationsAdhemerval Zanella2021-05-071-36/+0
| | | | | | | | | | | | | | And replace the generic algorithm with the Brian Kernighan's one. GCC optimize it with popcnt if the architecture supports, so there is no need to add the extra POPCNT define to enable it. This is really a micro-optimization that only adds complexity: recent ABIs already support it (x86-64-v2 or power64le) and it simplifies the code for internal usage, since i686 does not allow an internal iFUNC call. Checked on x86_64-linux-gnu, aarch64-linux-gnu, and powerpc64le-linux-gnu.
* x86: Optimize memchr-evex.SNoah Goldstein2021-05-031-225/+322
| | | | | | | | | | | | No bug. This commit optimizes memchr-evex.S. The optimizations include replacing some branches with cmovcc, avoiding some branches entirely in the less_4x_vec case, making the page cross logic less strict, saving some ALU in the alignment process, and most importantly increasing ILP in the 4x loop. test-memchr, test-rawmemchr, and test-wmemchr are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Optimize memchr-avx2.SNoah Goldstein2021-05-031-178/+247
| | | | | | | | | | | No bug. This commit optimizes memchr-avx2.S. The optimizations include replacing some branches with cmovcc, avoiding some branches entirely in the less_4x_vec case, making the page cross logic less strict, asaving a few instructions the in loop return loop. test-memchr, test-rawmemchr, and test-wmemchr are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* x86: Optimize strchr-evex.SNoah Goldstein2021-04-251-174/+218
| | | | | | | | | | No bug. This commit optimizes strchr-evex.S. The optimizations are mostly small things such as save an ALU in the alignment process, saving a few instructions in the loop return. The one significant change is saving 2 instructions in the 4x loop. test-strchr, test-strchrnul, test-wcschr, and test-wcschrnul are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86: Optimize strchr-avx2.SNoah Goldstein2021-04-251-117/+169
| | | | | | | | | | No bug. This commit optimizes strchr-avx2.S. The optimizations are all small things such as save an ALU in the alignment process, saving a few instructions in the loop return, saving some bytes in the main loop, and increasing the ILP in the return cases. test-strchr, test-strchrnul, test-wcschr, and test-wcschrnul are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86: Optimize strlen-avx2.SNoah Goldstein2021-04-192-214/+334
| | | | | | | | | | No bug. This commit optimizes strlen-avx2.S. The optimizations are mostly small things but they add up to roughly 10-30% performance improvement for strlen. The results for strnlen are bit more ambiguous. test-strlen, test-strnlen, test-wcslen, and test-wcsnlen are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86: Optimize strlen-evex.SNoah Goldstein2021-04-191-264/+317
| | | | | | | | | | No bug. This commit optimizes strlen-evex.S. The optimizations are mostly small things but they add up to roughly 10-30% performance improvement for strlen. The results for strnlen are bit more ambiguous. test-strlen, test-strnlen, test-wcslen, and test-wcsnlen are all passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86: Optimize less_vec evex and avx512 memset-vec-unaligned-erms.SNoah Goldstein2021-04-195-27/+74
| | | | | | | | No bug. This commit adds optimized cased for less_vec memset case that uses the avx512vl/avx512bw mask store avoiding the excessive branches. test-memset and test-wmemset are passing. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86-64: Require BMI2 for strchr-avx2.SH.J. Lu2021-04-192-5/+11
| | | | | | | | | | | | | | | | | Since strchr-avx2.S updated by commit 1f745ecc2109890886b161d4791e1406fdfc29b8 Author: noah <goldstein.w.n@gmail.com> Date: Wed Feb 3 00:38:59 2021 -0500 x86-64: Refactor and improve performance of strchr-avx2.S uses sarx: c4 e2 72 f7 c0 sarx %ecx,%eax,%eax for strchr-avx2 family functions, require BMI2 in ifunc-impl-list.c and ifunc-avx2.h.
* x86-64: Require BMI2 for __strlen_evex and __strnlen_evexH.J. Lu2021-04-191-2/+4
| | | | | | | | | | | | | | | | | Since __strlen_evex and __strnlen_evex added by commit 1fd8c163a83d96ace1ff78fa6bac7aee084f6f77 Author: H.J. Lu <hjl.tools@gmail.com> Date: Fri Mar 5 06:24:52 2021 -0800 x86-64: Add ifunc-avx2.h functions with 256-bit EVEX use sarx: c4 e2 6a f7 c0 sarx %edx,%eax,%eax require BMI2 for __strlen_evex and __strnlen_evex in ifunc-impl-list.c. ifunc-avx2.h already requires BMI2 for EVEX implementation.
* x86: Update large memcpy case in memmove-vec-unaligned-erms.Snoah2021-04-161-73/+265
| | | | | | | | | | | | | | No Bug. This commit updates the large memcpy case (no overlap). The update is to perform memcpy on either 2 or 4 contiguous pages at once. This 1) helps to alleviate the affects of false memory aliasing when destination and source have a close 4k alignment and 2) In most cases and for most DRAM units is a modestly more efficient access pattern. These changes are a clear performance improvement for VEC_SIZE =16/32, though more ambiguous for VEC_SIZE=64. test-memcpy, test-memccpy, test-mempcpy, test-memmove, and tst-memmove-overflow all pass. Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
* x86-64: Fix ifdef indentation in strlen-evex.SSunil K Pandey2021-04-011-8/+8
| | | | | Fix some indentations of ifdef in file strlen-evex.S which are off by 1 and confusing to read.
* x86-64: Use ZMM16-ZMM31 in AVX512 memmove family functionsH.J. Lu2021-03-293-19/+42
| | | | | | Update ifunc-memmove.h to select the function optimized with AVX512 instructions using ZMM16-ZMM31 registers to avoid RTM abort with usable AVX512VL since VZEROUPPER isn't needed at function exit.
* x86-64: Use ZMM16-ZMM31 in AVX512 memset family functionsH.J. Lu2021-03-294-24/+31
| | | | | | | Update ifunc-memset.h/ifunc-wmemset.h to select the function optimized with AVX512 instructions using ZMM16-ZMM31 registers to avoid RTM abort with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at function exit.
* x86-64: Add AVX optimized string/memory functions for RTMH.J. Lu2021-03-2951-248/+648
| | | | | | | | | | | | | | | | | Since VZEROUPPER triggers RTM abort while VZEROALL won't, select AVX optimized string/memory functions with xtest jz 1f vzeroall ret 1: vzeroupper ret at function exit on processors with usable RTM, but without 256-bit EVEX instructions to avoid VZEROUPPER inside a transactionally executing RTM region.
* x86-64: Add memcmp family functions with 256-bit EVEXH.J. Lu2021-03-295-4/+467
| | | | | | | Update ifunc-memcmp.h to select the function optimized with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM abort with usable AVX512VL, AVX512BW and MOVBE since VZEROUPPER isn't needed at function exit.
* x86-64: Add memset family functions with 256-bit EVEXH.J. Lu2021-03-296-14/+90
| | | | | | | Update ifunc-memset.h/ifunc-wmemset.h to select the function optimized with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM abort with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at function exit.
* x86-64: Add memmove family functions with 256-bit EVEXH.J. Lu2021-03-295-11/+104
| | | | | | Update ifunc-memmove.h to select the function optimized with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM abort with usable AVX512VL since VZEROUPPER isn't needed at function exit.
* x86-64: Add strcpy family functions with 256-bit EVEXH.J. Lu2021-03-299-3/+1339
| | | | | | Update ifunc-strcpy.h to select the function optimized with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM abort with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at function exit.
* x86-64: Add ifunc-avx2.h functions with 256-bit EVEXH.J. Lu2021-03-2924-17/+2995
| | | | | | | | | | Update ifunc-avx2.h, strchr.c, strcmp.c, strncmp.c and wcsnlen.c to select the function optimized with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM abort with usable AVX512VL, AVX512BW and BMI2 since VZEROUPPER isn't needed at function exit. For strcmp/strncmp, prefer AVX2 strcmp/strncmp if Prefer_AVX2_STRCMP is set.
* x86-64: Refactor and improve performance of strchr-avx2.Snoah2021-02-082-113/+113
| | | | | | | | No bug. Just seemed the performance could be improved a bit. Observed and expected behavior are unchanged. Optimized body of main loop. Updated page cross logic and optimized accordingly. Made a few minor instruction selection modifications. No regressions in test suite. Both test-strchrnul and test-strchr passed.
* x86: Adding an upper bound for Enhanced REP MOVSB.Sajan Karumanchi2021-02-021-2/+5
| | | | | | | | | | | | | | | In the process of optimizing memcpy for AMD machines, we have found the vector move operations are outperforming enhanced REP MOVSB for data transfers above the L2 cache size on Zen3 architectures. To handle this use case, we are adding an upper bound parameter on enhanced REP MOVSB:'__x86_rep_movsb_stop_threshold'. As per large-bench results, we are configuring this parameter to the L2 cache size for AMD machines and applicable from Zen3 architecture supporting the ERMS feature. For architectures other than AMD, it is the computed value of non-temporal threshold parameter. Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
* x86-64: Avoid rep movsb with short distance [BZ #27130]H.J. Lu2021-01-041-0/+21
| | | | | | | | | | | | | | | | | When copying with "rep movsb", if the distance between source and destination is N*4GB + [1..63] with N >= 0, performance may be very slow. This patch updates memmove-vec-unaligned-erms.S for AVX and AVX512 versions with the distance in RCX: cmpl $63, %ecx // Don't use "rep movsb" if ECX <= 63 jbe L(Don't use rep movsb") Use "rep movsb" Benchtests data with bench-memcpy, bench-memcpy-large, bench-memcpy-random and bench-memcpy-walk on Skylake, Ice Lake and Tiger Lake show that its performance impact is within noise range as "rep movsb" is only used for data size >= 4KB.
* Update copyright dates with scripts/update-copyrightsPaul Eggert2021-01-02122-122/+122
| | | | | | | | | | | | | | | | 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
* x86: Install <sys/platform/x86.h> [BZ #26124]H.J. Lu2020-09-112-100/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Install <sys/platform/x86.h> so that programmers can do #if __has_include(<sys/platform/x86.h>) #include <sys/platform/x86.h> #endif ... if (CPU_FEATURE_USABLE (SSE2)) ... if (CPU_FEATURE_USABLE (AVX2)) ... <sys/platform/x86.h> exports only: enum { COMMON_CPUID_INDEX_1 = 0, COMMON_CPUID_INDEX_7, COMMON_CPUID_INDEX_80000001, COMMON_CPUID_INDEX_D_ECX_1, COMMON_CPUID_INDEX_80000007, COMMON_CPUID_INDEX_80000008, COMMON_CPUID_INDEX_7_ECX_1, /* Keep the following line at the end. */ COMMON_CPUID_INDEX_MAX }; struct cpuid_features { struct cpuid_registers cpuid; struct cpuid_registers usable; }; struct cpu_features { struct cpu_features_basic basic; struct cpuid_features features[COMMON_CPUID_INDEX_MAX]; }; /* Get a pointer to the CPU features structure. */ extern const struct cpu_features *__x86_get_cpu_features (unsigned int max) __attribute__ ((const)); Since all feature checks are done through macros, programs compiled with a newer <sys/platform/x86.h> are compatible with the older glibc binaries as long as the layout of struct cpu_features is identical. The features array can be expanded with backward binary compatibility for both .o and .so files. When COMMON_CPUID_INDEX_MAX is increased to support new processor features, __x86_get_cpu_features in the older glibc binaries returns NULL and HAS_CPU_FEATURE/CPU_FEATURE_USABLE return false on the new processor feature. No new symbol version is neeeded. Both CPU_FEATURE_USABLE and HAS_CPU_FEATURE are provided. HAS_CPU_FEATURE can be used to identify processor features. Note: Although GCC has __builtin_cpu_supports, it only supports a subset of <sys/platform/x86.h> and it is equivalent to CPU_FEATURE_USABLE. It doesn't support HAS_CPU_FEATURE.
* x86: Support usable check for all CPU featuresH.J. Lu2020-07-1316-159/+159
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support usable check for all CPU features with the following changes: 1. Change struct cpu_features to struct cpuid_features { struct cpuid_registers cpuid; struct cpuid_registers usable; }; struct cpu_features { struct cpu_features_basic basic; struct cpuid_features features[COMMON_CPUID_INDEX_MAX]; unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX]; ... }; so that there is a usable bit for each cpuid bit. 2. After the cpuid bits have been initialized, copy the known bits to the usable bits. EAX/EBX from INDEX_1 and EAX from INDEX_7 aren't used for CPU feature detection. 3. Clear the usable bits which require OS support. 4. If the feature is supported by OS, copy its cpuid bit to its usable bit. 5. Replace HAS_CPU_FEATURE and CPU_FEATURES_CPU_P with CPU_FEATURE_USABLE and CPU_FEATURE_USABLE_P to check if a feature is usable. 6. Add DEPR_FPU_CS_DS for INDEX_7_EBX_13. 7. Unset MPX feature since it has been deprecated. The results are 1. If the feature is known and doesn't requre OS support, its usable bit is copied from the cpuid bit. 2. Otherwise, its usable bit is copied from the cpuid bit only if the feature is known to supported by OS. 3. CPU_FEATURE_USABLE/CPU_FEATURE_USABLE_P are used to check if the feature can be used. 4. HAS_CPU_FEATURE/CPU_FEATURE_CPU_P are used to check if CPU supports the feature.
* x86: Add thresholds for "rep movsb/stosb" to tunablesH.J. Lu2020-07-062-26/+2
| | | | | | | | | | Add x86_rep_movsb_threshold and x86_rep_stosb_threshold to tunables to update thresholds for "rep movsb" and "rep stosb" at run-time. Note that the user specified threshold for "rep movsb" smaller than the minimum threshold will be ignored. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Fix avx2 strncmp offset compare condition check [BZ #25933]Sunil K Pandey2020-06-171-0/+15
| | | | | | | | | strcmp-avx2.S: In avx2 strncmp function, strings are compared in chunks of 4 vector size(i.e. 32x4=128 byte for avx2). After first 4 vector size comparison, code must check whether it already passed the given offset. This patch implement avx2 offset check condition for strncmp function, if both string compare same for first 4 vector size.
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-08 10:46:12 +0000