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x86: Remove __mmask intrinsics in strstr-avx512.c

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The intrinsics are not available before GCC7 and using standard
operators generates code of equivalent or better quality.

Removed:
    _cvtmask64_u64
    _kshiftri_mask64
    _kand_mask64

Geometric Mean of 5 Runs of Full Benchmark Suite New / Old: 0.958
This commit is contained in:
Noah Goldstein 2022-07-12 11:48:04 -07:00
parent 9c38deec96
commit f2698954ff
1 changed files with 10 additions and 6 deletions
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16
sysdeps/x86_64/multiarch/strstr-avx512.c
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@ -26,6 +26,10 @@
#define ZMM_SIZE_IN_BYTES 64
#define PAGESIZE 4096
#define cvtmask64_u64(...) (uint64_t) (__VA_ARGS__)
#define kshiftri_mask64(x, y) ((x) >> (y))
#define kand_mask64(x, y) ((x) & (y))
/*
Returns the index of the first edge within the needle, returns 0 if no edge
is found. Example: 'ab' is the first edge in 'aaaaaaaaaabaarddg'
@ -133,15 +137,15 @@ __strstr_avx512 (const char *haystack, const char *ned)
__m512i hay0 = _mm512_maskz_loadu_epi8 (loadmask, haystack + hay_index);
/* Search for NULL and compare only till null char */
uint64_t nullmask
= _cvtmask64_u64 (_mm512_mask_testn_epi8_mask (loadmask, hay0, hay0));
= cvtmask64_u64 (_mm512_mask_testn_epi8_mask (loadmask, hay0, hay0));
uint64_t cmpmask = nullmask ^ (nullmask - ONE_64BIT);
cmpmask = cmpmask & _cvtmask64_u64 (loadmask);
cmpmask = cmpmask & cvtmask64_u64 (loadmask);
/* Search for the 2 charaters of needle */
__mmask64 k0 = _mm512_cmpeq_epi8_mask (hay0, ned0);
__mmask64 k1 = _mm512_cmpeq_epi8_mask (hay0, ned1);
k1 = _kshiftri_mask64 (k1, 1);
k1 = kshiftri_mask64 (k1, 1);
/* k2 masks tell us if both chars from needle match */
uint64_t k2 = _cvtmask64_u64 (_kand_mask64 (k0, k1)) & cmpmask;
uint64_t k2 = cvtmask64_u64 (kand_mask64 (k0, k1)) & cmpmask;
/* For every match, search for the entire needle for a full match */
while (k2)
{
@ -178,13 +182,13 @@ __strstr_avx512 (const char *haystack, const char *ned)
hay0 = _mm512_loadu_si512 (haystack + hay_index);
hay1 = _mm512_load_si512 (haystack + hay_index
+ 1); // Always 64 byte aligned
nullmask = _cvtmask64_u64 (_mm512_testn_epi8_mask (hay1, hay1));
nullmask = cvtmask64_u64 (_mm512_testn_epi8_mask (hay1, hay1));
/* Compare only till null char */
cmpmask = nullmask ^ (nullmask - ONE_64BIT);
k0 = _mm512_cmpeq_epi8_mask (hay0, ned0);
k1 = _mm512_cmpeq_epi8_mask (hay1, ned1);
/* k2 masks tell us if both chars from needle match */
k2 = _cvtmask64_u64 (_kand_mask64 (k0, k1)) & cmpmask;
k2 = cvtmask64_u64 (kand_mask64 (k0, k1)) & cmpmask;
/* For every match, compare full strings for potential match */
while (k2)
{