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* x86: Add support for building {w}memset{_chk} with explicit ISA levelNoah Goldstein2022-07-051-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. Refactor files so that all implementations are in the multiarch directory - Moved the implementation portion of memset sse2 from memset.S to multiarch/memset-sse2.S - The non-multiarch file now only includes one of the implementations in the multiarch directory based on the compiled ISA level (only used for non-multiarch builds. Otherwise we go through the ifunc selector). 2. Add ISA level build guards to different implementations. - I.e memset-avx2-unaligned-erms.S which is ISA level 3 will only build if compiled ISA level <= 3. Otherwise there is no reason to include it as we will always use one of the ISA level 4 implementations (memset-evex-unaligned-erms.S). 3. Add new multiarch/rtld-memset.S that just include the non-multiarch memset.S which will in turn select the best implementation based on the compiled ISA level. 4. Refactor the ifunc selector and ifunc implementation list to use the ISA level aware wrapper macros that allow functions below the compiled ISA level (with a guranteed replacement) to be skipped. Tested with and without multiarch on x86_64 for ISA levels: {generic, x86-64-v2, x86-64-v3, x86-64-v4} And m32 with and without multiarch.
* x86_64: Remove bzero optimizationAdhemerval Zanella2022-05-161-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both symbols are marked as legacy in POSIX.1-2001 and removed on POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE or _DEFAULT_SOURCE. GCC also replaces bcopy with a memmove and bzero with memset on default configuration (to actually get a bzero libc call the code requires to omit string.h inclusion and built with -fno-builtin), so it is highly unlikely programs are actually calling libc bzero symbol. On a recent Linux distro (Ubuntu 22.04), there is no bzero calls by the installed binaries. $ cat count_bstring.sh #!/bin/bash files=`IFS=':';for i in $PATH; do test -d "$i" && find "$i" -maxdepth 1 -executable -type f; done` total=0 for file in $files; do symbols=`objdump -R $file 2>&1` if [ $? -eq 0 ]; then ncalls=`echo $symbols | grep -w $1 | wc -l` ((total=total+ncalls)) if [ $ncalls -gt 0 ]; then echo "$file: $ncalls" fi fi done echo "TOTAL=$total" $ ./count_bstring.sh bzero TOTAL=0 Checked on x86_64-linux-gnu.
* x86-64: Optimize bzeroH.J. Lu2022-02-081-0/+6
| | | | | | | | | | 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>
* x86: Improve vec generation in memset-vec-unaligned-erms.SNoah Goldstein2022-02-061-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* x86: Optimize memset-vec-unaligned-erms.SNoah Goldstein2021-10-121-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* x86-64: Add AVX optimized string/memory functions for RTMH.J. Lu2021-03-291-3/+9
| | | | | | | | | | | | | | | | | 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: Optimize wmemset with SSE2/AVX2/AVX512H.J. Lu2017-06-051-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The difference between memset and wmemset is byte vs int. Add stubs to SSE2/AVX2/AVX512 memset for wmemset with updated constant and size: SSE2 wmemset: shl $0x2,%rdx movd %esi,%xmm0 mov %rdi,%rax pshufd $0x0,%xmm0,%xmm0 jmp entry_from_wmemset SSE2 memset: movd %esi,%xmm0 mov %rdi,%rax punpcklbw %xmm0,%xmm0 punpcklwd %xmm0,%xmm0 pshufd $0x0,%xmm0,%xmm0 entry_from_wmemset: Since the ERMS versions of wmemset requires "rep stosl" instead of "rep stosb", only the vector store stubs of SSE2/AVX2/AVX512 wmemset are added. The SSE2 wmemset is about 3X faster and the AVX2 wmemset is about 6X faster on Haswell. * include/wchar.h (__wmemset_chk): New. * sysdeps/x86_64/memset.S (VDUP_TO_VEC0_AND_SET_RETURN): Renamed to MEMSET_VDUP_TO_VEC0_AND_SET_RETURN. (WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN): New. (WMEMSET_CHK_SYMBOL): Likewise. (WMEMSET_SYMBOL): Likewise. (__wmemset): Add hidden definition. (wmemset): Add weak hidden definition. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add wmemset_chk-nonshared. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add __wmemset_sse2_unaligned, __wmemset_avx2_unaligned, __wmemset_avx512_unaligned, __wmemset_chk_sse2_unaligned, __wmemset_chk_avx2_unaligned and __wmemset_chk_avx512_unaligned. * sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S (VDUP_TO_VEC0_AND_SET_RETURN): Renamed to ... (MEMSET_VDUP_TO_VEC0_AND_SET_RETURN): This. (WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN): New. (WMEMSET_SYMBOL): Likewise. * sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S (VDUP_TO_VEC0_AND_SET_RETURN): Renamed to ... (MEMSET_VDUP_TO_VEC0_AND_SET_RETURN): This. (WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN): New. (WMEMSET_SYMBOL): Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: Updated. (WMEMSET_CHK_SYMBOL): New. (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned)): Likewise. (WMEMSET_SYMBOL (__wmemset, unaligned)): Likewise. * sysdeps/x86_64/multiarch/memset.S (WMEMSET_SYMBOL): New. (libc_hidden_builtin_def): Also define __GI_wmemset and __GI___wmemset. (weak_alias): New. * sysdeps/x86_64/multiarch/wmemset.c: New file. * sysdeps/x86_64/multiarch/wmemset.h: Likewise. * sysdeps/x86_64/multiarch/wmemset_chk-nonshared.S: Likewise. * sysdeps/x86_64/multiarch/wmemset_chk.c: Likewise. * sysdeps/x86_64/wmemset.c: Likewise. * sysdeps/x86_64/wmemset_chk.c: Likewise.
* Don't put SSE2/AVX/AVX512 memmove/memset in ld.soH.J. Lu2016-04-031-8/+10
| | | | | | | | | | | | | | Since memmove and memset in ld.so don't use IFUNC, don't put SSE2, AVX and AVX512 memmove and memset in ld.so. * sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S: Skip if not in libc. * sysdeps/x86_64/multiarch/memmove-avx512-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S: Likewise.
* Add x86-64 memset with unaligned store and rep stosbH.J. Lu2016-03-311-0/+14
Implement x86-64 memset with unaligned store and rep movsb. Support 16-byte, 32-byte and 64-byte vector register sizes. A single file provides 2 implementations of memset, one with rep stosb and the other without rep stosb. They share the same codes when size is between 2 times of vector register size and REP_STOSB_THRESHOLD which defaults to 2KB. Key features: 1. Use overlapping store to avoid branch. 2. For size <= 4 times of vector register size, fully unroll the loop. 3. For size > 4 times of vector register size, store 4 times of vector register size at a time. [BZ #19881] * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memset-sse2-unaligned-erms, memset-avx2-unaligned-erms and memset-avx512-unaligned-erms. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Test __memset_chk_sse2_unaligned, __memset_chk_sse2_unaligned_erms, __memset_chk_avx2_unaligned, __memset_chk_avx2_unaligned_erms, __memset_chk_avx512_unaligned, __memset_chk_avx512_unaligned_erms, __memset_sse2_unaligned, __memset_sse2_unaligned_erms, __memset_erms, __memset_avx2_unaligned, __memset_avx2_unaligned_erms, __memset_avx512_unaligned_erms and __memset_avx512_unaligned. * sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S: New file. * sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: Likewise.
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