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Minor cleanups in x86-64 strstr.

This commit is contained in:
Ulrich Drepper 2009-07-21 07:52:12 -07:00
parent a8f895ebe1
commit ae612b04cc
2 changed files with 59 additions and 77 deletions
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5
ChangeLog
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@ -1,3 +1,8 @@
2009-07-21 Ulrich Drepper <drepper@redhat.com>
* sysdeps/x86_64/multiarch/strstr.c: Minor cleanups. Remove
unnecesary variables. Comment fixes.
2009-07-20 Ulrich Drepper <drepper@redhat.com> 2009-07-20 Ulrich Drepper <drepper@redhat.com>
* sysdeps/x86_64/multiarch/strstr.c [USE_AS_STRCASESTR] (STRSTR_SSE42): * sysdeps/x86_64/multiarch/strstr.c [USE_AS_STRCASESTR] (STRSTR_SSE42):

131
sysdeps/x86_64/multiarch/strstr.c
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@ -29,8 +29,7 @@
# include <locale/localeinfo.h> # include <locale/localeinfo.h>
# define LOADBYTE(C) tolower (C) # define LOADBYTE(C) tolower (C)
# define CMPBYTE(C1, C2) \ # define CMPBYTE(C1, C2) (tolower (C1) == tolower (C2))
((C1) == (C2) || tolower (C1) == tolower (C2))
#else #else
# define LOADBYTE(C) (C) # define LOADBYTE(C) (C)
# define CMPBYTE(C1, C2) ((C1) == (C2)) # define CMPBYTE(C1, C2) ((C1) == (C2))
@ -222,16 +221,14 @@ static int
__inline__ __attribute__ ((__always_inline__,)) __inline__ __attribute__ ((__always_inline__,))
KMP16Bovrlap (__m128i s2) KMP16Bovrlap (__m128i s2)
{ {
__m128i a, b; __m128i b = _mm_unpacklo_epi8 (s2, s2);
int bmsk, k1; __m128i a = _mm_unpacklo_epi8 (b, b);
b = _mm_unpacklo_epi8 (s2, s2);
a = _mm_unpacklo_epi8 (b, b);
a = _mm_shuffle_epi32 (a, 0); a = _mm_shuffle_epi32 (a, 0);
b = _mm_srli_si128 (s2, sizeof (char)); b = _mm_srli_si128 (s2, sizeof (char));
bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (b, a)); int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (b, a));
/* _BitScanForward(&k1, bmsk); */ /* _BitScanForward(&k1, bmsk); */
int k1;
__asm ("bsfl %[bmsk], %[k1]" : [k1] "=r" (k1) : [bmsk] "r" (bmsk)); __asm ("bsfl %[bmsk], %[k1]" : [k1] "=r" (k1) : [bmsk] "r" (bmsk));
if (!bmsk) if (!bmsk)
return 16; return 16;
@ -256,31 +253,18 @@ char *
__attribute__ ((section (".text.sse4.2"))) __attribute__ ((section (".text.sse4.2")))
STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2) STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
{ {
int len; #define p1 s1
int len1;
const unsigned char *p1 = s1;
const unsigned char *p2 = s2; const unsigned char *p2 = s2;
__m128i frag1;
__m128i frag2;
__m128i zero;
int cmp;
int cmp_c;
int cmp_z;
int cmp_s;
int kmp_fwd;
int bmsk;
int bmsk1;
const unsigned char *pt;
if (!p2[0]) if (p2[0] == '\0')
return (char *) p1; return (char *) p1;
if (!p1[0]) if (p1[0] == '\0')
return NULL; return NULL;
/* Check if p1 length is 1 byte long. */ /* Check if p1 length is 1 byte long. */
if (!p1[1]) if (p1[1] == '\0')
return !p2[1] && CMPBYTE (p1[0], p2[0]) ? (char *) p1 : NULL; return p2[1] == '\0' && CMPBYTE (p1[0], p2[0]) ? (char *) p1 : NULL;
#ifdef USE_AS_STRCASESTR #ifdef USE_AS_STRCASESTR
__m128i (*strloadu) (const unsigned char *); __m128i (*strloadu) (const unsigned char *);
@ -294,44 +278,39 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
#endif #endif
/* p1 > 1 byte long. Load up to 16 bytes of fragment. */ /* p1 > 1 byte long. Load up to 16 bytes of fragment. */
frag1 = strloadu (p1); __m128i frag1 = strloadu (p1);
if (p2[1]) __m128i frag2;
{ if (p2[1] != '\0')
/* p2 is > 1 byte long. */ /* p2 is > 1 byte long. */
frag2 = strloadu (p2); frag2 = strloadu (p2);
}
else else
{ frag2 = _mm_insert_epi8 (_mm_setzero_si128 (), LOADBYTE (p2[0]), 0);
zero = _mm_setzero_si128 ();
frag2 = _mm_insert_epi8 (zero, LOADBYTE(p2[0]), 0);
}
/* Unsigned bytes, equal order, does frag2 has null? */ /* Unsigned bytes, equal order, does frag2 has null? */
cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); int cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c); int cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c);
cmp = _mm_cmpistri (frag2, frag1, 0x0c); int cmp = _mm_cmpistri (frag2, frag1, 0x0c);
cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); int cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c);
if (cmp_s & cmp_c) if (cmp_s & cmp_c)
{ {
zero = _mm_setzero_si128 (); int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (frag2,
bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (frag2, zero)); _mm_setzero_si128 ()));
int len;
__asm ("bsfl %[bmsk], %[len]" __asm ("bsfl %[bmsk], %[len]"
: [len] "=r" (len) : [bmsk] "r" (bmsk)); : [len] "=r" (len) : [bmsk] "r" (bmsk));
p1 += cmp; p1 += cmp;
if ((len + cmp) <= 16) if ((len + cmp) <= 16)
return (char *) p1; return (char *) p1;
else
{ /* Load up to 16 bytes of fragment. */
/* Load up to 16 bytes of fragment. */ frag1 = strloadu (p1);
frag1 = strloadu (p1); cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c);
cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c);
cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c); cmp = _mm_cmpistri (frag2, frag1, 0x0c);
cmp = _mm_cmpistri (frag2, frag1, 0x0c); if ((len + cmp) <= 16)
if ((len + cmp) <= 16) return (char *) p1 + cmp;
return (char *) p1 + cmp;
}
} }
if (cmp_s) if (cmp_s)
@ -353,18 +332,16 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
if (!cmp_c) if (!cmp_c)
return NULL; return NULL;
else
{ /* Since s2 is less than 16 bytes, com_c is definitive
/* Since s2 is less than 16 bytes, com_c is definitive determination of full match. */
determination of full match. */ return (char *) p1 + cmp;
return (char *) p1 + cmp;
}
} }
/* General case, s2 is at least 16 bytes or more. /* General case, s2 is at least 16 bytes or more.
First, the common case of false-match at first byte of p2. */ First, the common case of false-match at first byte of p2. */
pt = NULL; const unsigned char *pt = NULL;
kmp_fwd = 0; int kmp_fwd = 0;
re_trace: re_trace:
while (!cmp_c) while (!cmp_c)
{ {
@ -378,11 +355,11 @@ re_trace:
frag1 = strloadu (p1); frag1 = strloadu (p1);
/* Unsigned bytes, equal order, is there a partial match? */ /* Unsigned bytes, equal order, is there a partial match? */
cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
cmp = _mm_cmpistri(frag2, frag1, 0x0c); cmp = _mm_cmpistri (frag2, frag1, 0x0c);
cmp_z = _mm_cmpistrz(frag2, frag1, 0x0c); cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c);
} }
/* Next, handle inital positive match as first byte of p2. We have /* Next, handle initial positive match as first byte of p2. We have
a partial fragment match, make full determination until we reached a partial fragment match, make full determination until we reached
end of s2. */ end of s2. */
if (!cmp) if (!cmp)
@ -394,7 +371,7 @@ re_trace:
p1 += 16; p1 += 16;
p2 += 16; p2 += 16;
/* Load up to 16 bytes of fragment. */ /* Load up to 16 bytes of fragment. */
frag2 = strloadu(p2); frag2 = strloadu (p2);
} }
else else
{ {
@ -426,7 +403,7 @@ re_trace:
cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c);
} }
/* Full determination yielded false result, retrace s1 to next /* Full determination yielded a false result, retrace s1 to next
starting position. starting position.
Zflg 1 0 1 0/1 Zflg 1 0 1 0/1
Sflg 0 1 1 0/1 Sflg 0 1 1 0/1
@ -435,18 +412,20 @@ re_trace:
false match retrace s1 else false false match retrace s1 else false
*/ */
if(cmp_s & !cmp) if (cmp_s & !cmp)
return (char *) pt; return (char *) pt;
else if (cmp_z) if (cmp_z)
{ {
if (!cmp_s) if (!cmp_s)
return NULL; return NULL;
/* Handle both zero and sign flag set and s1 is shorter in /* Handle both zero and sign flag set and s1 is shorter in
length. */ length. */
zero = _mm_setzero_si128 (); __m128i zero = _mm_setzero_si128 ();
bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag2)); int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag2));
bmsk1 = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag1)); int bmsk1 = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag1));
int len;
int len1;
__asm ("bsfl %[bmsk], %[len]" __asm ("bsfl %[bmsk], %[len]"
: [len] "=r" (len) : [bmsk] "r" (bmsk)); : [len] "=r" (len) : [bmsk] "r" (bmsk));
__asm ("bsfl %[bmsk1], %[len1]" __asm ("bsfl %[bmsk1], %[len1]"
@ -471,13 +450,11 @@ re_trace:
/* Since s2 is at least 16 bytes long, we're certain there is no /* Since s2 is at least 16 bytes long, we're certain there is no
match. */ match. */
if (!p1[0]) if (p1[0] == '\0')
return NULL; return NULL;
else
{ /* Load up to 16 bytes of fragment. */
/* Load up to 16 bytes of fragment. */ frag1 = strloadu (p1);
frag1 = strloadu (p1);
}
/* Unsigned bytes, equal order, is there a partial match? */ /* Unsigned bytes, equal order, is there a partial match? */
cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);