diff options
Diffstat (limited to 'sysdeps/x86_64/multiarch/strspn-c.c')
| -rw-r--r-- | sysdeps/x86_64/multiarch/strspn-c.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/sysdeps/x86_64/multiarch/strspn-c.c b/sysdeps/x86_64/multiarch/strspn-c.c new file mode 100644 index 0000000000..5b99f0d383 --- /dev/null +++ b/sysdeps/x86_64/multiarch/strspn-c.c @@ -0,0 +1,284 @@ +/* strspn with SSE4.2 intrinsics + Copyright (C) 2009 Free Software Foundation, Inc. + Contributed by Intel Corporation. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <nmmintrin.h> +#include <string.h> + +/* We use 0x12: + _SIDD_SBYTE_OPS + | _SIDD_CMP_EQUAL_ANY + | _SIDD_NEGATIVE_POLARITY + | _SIDD_LEAST_SIGNIFICANT + on pcmpistri to compare xmm/mem128 + + 0 1 2 3 4 5 6 7 8 9 A B C D E F + X X X X X X X X X X X X X X X X + + against xmm + + 0 1 2 3 4 5 6 7 8 9 A B C D E F + A A A A A A A A A A A A A A A A + + to find out if the first 16byte data element has any non-A byte and + the offset of the first byte. There are 2 cases: + + 1. The first 16byte data element has the non-A byte, including + EOS, at the offset X. + 2. The first 16byte data element is valid and doesn't have the non-A + byte. + + Here is the table of ECX, CFlag, ZFlag and SFlag for 2 cases: + + case ECX CFlag ZFlag SFlag + 1 X 1 0/1 0 + 2 16 0 0 0 + + We exit from the loop for case 1. */ + +extern size_t __strspn_sse2 (const char *, const char *); + + +size_t +__attribute__ ((section (".text.sse4.2"))) +__strspn_sse42 (const char *s, const char *a) +{ + if (*a == 0) + return 0; + + const char *aligned; + __m128i mask; + int offset = (int) ((size_t) a & 15); + if (offset != 0) + { + /* Load masks. */ + aligned = (const char *) ((size_t) a & 0xfffffffffffffff0L); + __m128i mask0 = _mm_load_si128 ((__m128i *) aligned); + + switch (offset) + { + case 1: + mask = _mm_srli_si128 (mask0, 1); + break; + case 2: + mask = _mm_srli_si128 (mask0, 2); + break; + case 3: + mask = _mm_srli_si128 (mask0, 3); + break; + case 4: + mask = _mm_srli_si128 (mask0, 4); + break; + case 5: + mask = _mm_srli_si128 (mask0, 5); + break; + case 6: + mask = _mm_srli_si128 (mask0, 6); + break; + case 7: + mask = _mm_srli_si128 (mask0, 7); + break; + case 8: + mask = _mm_srli_si128 (mask0, 8); + break; + case 9: + mask = _mm_srli_si128 (mask0, 9); + break; + case 10: + mask = _mm_srli_si128 (mask0, 10); + break; + case 11: + mask = _mm_srli_si128 (mask0, 11); + break; + case 12: + mask = _mm_srli_si128 (mask0, 12); + break; + case 13: + mask = _mm_srli_si128 (mask0, 13); + break; + case 14: + mask = _mm_srli_si128 (mask0, 14); + break; + case 15: + mask = _mm_srli_si128 (mask0, 15); + break; + } + + /* Find where the NULL terminator is. */ + int length = _mm_cmpistri (mask, mask, 0x3a); + if (length == 16 - offset) + { + /* There is no NULL terminator. */ + __m128i mask1 = _mm_load_si128 ((__m128i *) (aligned + 16)); + int index = _mm_cmpistri (mask1, mask1, 0x3a); + length += index; + + /* Don't use SSE4.2 if the length of A > 16. */ + if (length > 16) + return __strspn_sse2 (s, a); + + if (index != 0) + { + /* Combine mask0 and mask1. */ + switch (offset) + { + case 1: + mask = _mm_alignr_epi8 (mask1, mask0, 1); + break; + case 2: + mask = _mm_alignr_epi8 (mask1, mask0, 2); + break; + case 3: + mask = _mm_alignr_epi8 (mask1, mask0, 3); + break; + case 4: + mask = _mm_alignr_epi8 (mask1, mask0, 4); + break; + case 5: + mask = _mm_alignr_epi8 (mask1, mask0, 5); + break; + case 6: + mask = _mm_alignr_epi8 (mask1, mask0, 6); + break; + case 7: + mask = _mm_alignr_epi8 (mask1, mask0, 7); + break; + case 8: + mask = _mm_alignr_epi8 (mask1, mask0, 8); + break; + case 9: + mask = _mm_alignr_epi8 (mask1, mask0, 9); + break; + case 10: + mask = _mm_alignr_epi8 (mask1, mask0, 10); + break; + case 11: + mask = _mm_alignr_epi8 (mask1, mask0, 11); + break; + case 12: + mask = _mm_alignr_epi8 (mask1, mask0, 12); + break; + case 13: + mask = _mm_alignr_epi8 (mask1, mask0, 13); + break; + case 14: + mask = _mm_alignr_epi8 (mask1, mask0, 14); + break; + case 15: + mask = _mm_alignr_epi8 (mask1, mask0, 15); + break; + } + } + } + } + else + { + /* A is aligned. */ + mask = _mm_load_si128 ((__m128i *) a); + + /* Find where the NULL terminator is. */ + int length = _mm_cmpistri (mask, mask, 0x3a); + if (length == 16) + { + /* There is no NULL terminator. Don't use SSE4.2 if the length + of A > 16. */ + if (a[16] != 0) + return __strspn_sse2 (s, a); + } + } + + offset = (int) ((size_t) s & 15); + if (offset != 0) + { + /* Check partial string. */ + aligned = (const char *) ((size_t) s & 0xfffffffffffffff0L); + __m128i value = _mm_load_si128 ((__m128i *) aligned); + + switch (offset) + { + case 1: + value = _mm_srli_si128 (value, 1); + break; + case 2: + value = _mm_srli_si128 (value, 2); + break; + case 3: + value = _mm_srli_si128 (value, 3); + break; + case 4: + value = _mm_srli_si128 (value, 4); + break; + case 5: + value = _mm_srli_si128 (value, 5); + break; + case 6: + value = _mm_srli_si128 (value, 6); + break; + case 7: + value = _mm_srli_si128 (value, 7); + break; + case 8: + value = _mm_srli_si128 (value, 8); + break; + case 9: + value = _mm_srli_si128 (value, 9); + break; + case 10: + value = _mm_srli_si128 (value, 10); + break; + case 11: + value = _mm_srli_si128 (value, 11); + break; + case 12: + value = _mm_srli_si128 (value, 12); + break; + case 13: + value = _mm_srli_si128 (value, 13); + break; + case 14: + value = _mm_srli_si128 (value, 14); + break; + case 15: + value = _mm_srli_si128 (value, 15); + break; + } + + int length = _mm_cmpistri (mask, value, 0x12); + /* No need to check CFlag since it is always 1. */ + if (length < 16 - offset) + return length; + /* Find where the NULL terminator is. */ + int index = _mm_cmpistri (value, value, 0x3a); + if (index < 16 - offset) + return length; + aligned += 16; + } + else + aligned = s; + + while (1) + { + __m128i value = _mm_load_si128 ((__m128i *) aligned); + int index = _mm_cmpistri (mask, value, 0x12); + int cflag = _mm_cmpistrc (mask, value, 0x12); + if (cflag) + return (size_t) (aligned + index - s); + aligned += 16; + } +} |