glibc/sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S

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#if IS_IN (libc)
# define VEC_SIZE 32
# define VEC(i) ymm##i
X86-64: Use non-temporal store in memcpy on large data The large memcpy micro benchmark in glibc shows that there is a regression with large data on Haswell machine. non-temporal store in memcpy on large data can improve performance significantly. This patch adds a threshold to use non temporal store which is 6 times of shared cache size. When size is above the threshold, non temporal store will be used, but avoid non-temporal store if there is overlap between destination and source since destination may be in cache when source is loaded. For size below 8 vector register width, we load all data into registers and store them together. Only forward and backward loops, which move 4 vector registers at a time, are used to support overlapping addresses. For forward loop, we load the last 4 vector register width of data and the first vector register width of data into vector registers before the loop and store them after the loop. For backward loop, we load the first 4 vector register width of data and the last vector register width of data into vector registers before the loop and store them after the loop. [BZ #19928] * sysdeps/x86_64/cacheinfo.c (__x86_shared_non_temporal_threshold): New. (init_cacheinfo): Set __x86_shared_non_temporal_threshold to 6 times of shared cache size. * sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S (VMOVNT): New. * sysdeps/x86_64/multiarch/memmove-avx512-unaligned-erms.S (VMOVNT): Likewise. * sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S (VMOVNT): Likewise. (VMOVU): Changed to movups for smaller code sizes. (VMOVA): Changed to movaps for smaller code sizes. * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Update comments. (PREFETCH): New. (PREFETCH_SIZE): Likewise. (PREFETCHED_LOAD_SIZE): Likewise. (PREFETCH_ONE_SET): Likewise. Rewrite to use forward and backward loops, which move 4 vector registers at a time, to support overlapping addresses and use non temporal store if size is above the threshold and there is no overlap between destination and source.
2016-04-12 15:10:31 +00:00
# define VMOVNT vmovntdq
# define VMOVU vmovdqu
# define VMOVA vmovdqa
# define MOV_SIZE 4
# define SECTION(p) p##.avx
# define MEMMOVE_SYMBOL(p,s) p##_avx_##s
Add x86-64 memmove with unaligned load/store and rep movsb Implement x86-64 memmove with unaligned load/store and rep movsb. Support 16-byte, 32-byte and 64-byte vector register sizes. When size <= 8 times of vector register size, there is no check for address overlap bewteen source and destination. Since overhead for overlap check is small when size > 8 times of vector register size, memcpy is an alias of memmove. A single file provides 2 implementations of memmove, one with rep movsb and the other without rep movsb. They share the same codes when size is between 2 times of vector register size and REP_MOVSB_THRESHOLD which is 2KB for 16-byte vector register size and scaled up by large vector register size. Key features: 1. Use overlapping load and store to avoid branch. 2. For size <= 8 times of vector register size, load all sources into registers and store them together. 3. If there is no address overlap bewteen source and destination, copy from both ends with 4 times of vector register size at a time. 4. If address of destination > address of source, backward copy 8 times of vector register size at a time. 5. Otherwise, forward copy 8 times of vector register size at a time. 6. Use rep movsb only for forward copy. Avoid slow backward rep movsb by fallbacking to backward copy 8 times of vector register size at a time. 7. Skip when address of destination == address of source. [BZ #19776] * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memmove-sse2-unaligned-erms, memmove-avx-unaligned-erms and memmove-avx512-unaligned-erms. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Test __memmove_chk_avx512_unaligned_2, __memmove_chk_avx512_unaligned_erms, __memmove_chk_avx_unaligned_2, __memmove_chk_avx_unaligned_erms, __memmove_chk_sse2_unaligned_2, __memmove_chk_sse2_unaligned_erms, __memmove_avx_unaligned_2, __memmove_avx_unaligned_erms, __memmove_avx512_unaligned_2, __memmove_avx512_unaligned_erms, __memmove_erms, __memmove_sse2_unaligned_2, __memmove_sse2_unaligned_erms, __memcpy_chk_avx512_unaligned_2, __memcpy_chk_avx512_unaligned_erms, __memcpy_chk_avx_unaligned_2, __memcpy_chk_avx_unaligned_erms, __memcpy_chk_sse2_unaligned_2, __memcpy_chk_sse2_unaligned_erms, __memcpy_avx_unaligned_2, __memcpy_avx_unaligned_erms, __memcpy_avx512_unaligned_2, __memcpy_avx512_unaligned_erms, __memcpy_sse2_unaligned_2, __memcpy_sse2_unaligned_erms, __memcpy_erms, __mempcpy_chk_avx512_unaligned_2, __mempcpy_chk_avx512_unaligned_erms, __mempcpy_chk_avx_unaligned_2, __mempcpy_chk_avx_unaligned_erms, __mempcpy_chk_sse2_unaligned_2, __mempcpy_chk_sse2_unaligned_erms, __mempcpy_avx512_unaligned_2, __mempcpy_avx512_unaligned_erms, __mempcpy_avx_unaligned_2, __mempcpy_avx_unaligned_erms, __mempcpy_sse2_unaligned_2, __mempcpy_sse2_unaligned_erms and __mempcpy_erms. * sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S: New file. * sysdeps/x86_64/multiarch/memmove-avx512-unaligned-erms.S: Likwise. * sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S: Likwise. * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Likwise.
2016-03-31 17:04:26 +00:00
# include "memmove-vec-unaligned-erms.S"
#endif