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Minor cleanups in x86-64 strstr.
This commit is contained in:
Ulrich Drepper
parent
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commit
ae612b04cc
@ -1,3 +1,8 @@
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2009-07-21 Ulrich Drepper <drepper@redhat.com>
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* sysdeps/x86_64/multiarch/strstr.c: Minor cleanups. Remove
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unnecesary variables. Comment fixes.
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2009-07-20 Ulrich Drepper <drepper@redhat.com>
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* sysdeps/x86_64/multiarch/strstr.c [USE_AS_STRCASESTR] (STRSTR_SSE42):
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@ -29,8 +29,7 @@
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# include <locale/localeinfo.h>
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# define LOADBYTE(C) tolower (C)
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# define CMPBYTE(C1, C2) \
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((C1) == (C2) || tolower (C1) == tolower (C2))
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# define CMPBYTE(C1, C2) (tolower (C1) == tolower (C2))
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#else
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# define LOADBYTE(C) (C)
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# define CMPBYTE(C1, C2) ((C1) == (C2))
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@ -222,16 +221,14 @@ static int
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__inline__ __attribute__ ((__always_inline__,))
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KMP16Bovrlap (__m128i s2)
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{
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__m128i a, b;
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int bmsk, k1;
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b = _mm_unpacklo_epi8 (s2, s2);
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a = _mm_unpacklo_epi8 (b, b);
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__m128i b = _mm_unpacklo_epi8 (s2, s2);
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__m128i a = _mm_unpacklo_epi8 (b, b);
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a = _mm_shuffle_epi32 (a, 0);
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b = _mm_srli_si128 (s2, sizeof (char));
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bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (b, a));
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int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (b, a));
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/* _BitScanForward(&k1, bmsk); */
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int k1;
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__asm ("bsfl %[bmsk], %[k1]" : [k1] "=r" (k1) : [bmsk] "r" (bmsk));
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if (!bmsk)
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return 16;
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@ -256,31 +253,18 @@ char *
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__attribute__ ((section (".text.sse4.2")))
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STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
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{
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int len;
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int len1;
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const unsigned char *p1 = s1;
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#define p1 s1
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const unsigned char *p2 = s2;
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__m128i frag1;
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__m128i frag2;
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__m128i zero;
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int cmp;
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int cmp_c;
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int cmp_z;
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int cmp_s;
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int kmp_fwd;
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int bmsk;
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int bmsk1;
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const unsigned char *pt;
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if (!p2[0])
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if (p2[0] == '\0')
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return (char *) p1;
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if (!p1[0])
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if (p1[0] == '\0')
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return NULL;
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/* Check if p1 length is 1 byte long. */
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if (!p1[1])
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return !p2[1] && CMPBYTE (p1[0], p2[0]) ? (char *) p1 : NULL;
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if (p1[1] == '\0')
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return p2[1] == '\0' && CMPBYTE (p1[0], p2[0]) ? (char *) p1 : NULL;
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#ifdef USE_AS_STRCASESTR
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__m128i (*strloadu) (const unsigned char *);
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@ -294,35 +278,31 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
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#endif
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/* p1 > 1 byte long. Load up to 16 bytes of fragment. */
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frag1 = strloadu (p1);
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__m128i frag1 = strloadu (p1);
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if (p2[1])
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{
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__m128i frag2;
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if (p2[1] != '\0')
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/* p2 is > 1 byte long. */
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frag2 = strloadu (p2);
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}
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else
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{
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zero = _mm_setzero_si128 ();
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frag2 = _mm_insert_epi8 (zero, LOADBYTE(p2[0]), 0);
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}
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frag2 = _mm_insert_epi8 (_mm_setzero_si128 (), LOADBYTE (p2[0]), 0);
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/* Unsigned bytes, equal order, does frag2 has null? */
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cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
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cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c);
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cmp = _mm_cmpistri (frag2, frag1, 0x0c);
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cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c);
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int cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
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int cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c);
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int cmp = _mm_cmpistri (frag2, frag1, 0x0c);
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int cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c);
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if (cmp_s & cmp_c)
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{
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zero = _mm_setzero_si128 ();
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bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (frag2, zero));
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int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (frag2,
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_mm_setzero_si128 ()));
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int len;
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__asm ("bsfl %[bmsk], %[len]"
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: [len] "=r" (len) : [bmsk] "r" (bmsk));
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p1 += cmp;
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if ((len + cmp) <= 16)
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return (char *) p1;
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else
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{
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/* Load up to 16 bytes of fragment. */
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frag1 = strloadu (p1);
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cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
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@ -332,7 +312,6 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
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if ((len + cmp) <= 16)
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return (char *) p1 + cmp;
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}
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}
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if (cmp_s)
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{
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@ -353,18 +332,16 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2)
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if (!cmp_c)
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return NULL;
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else
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{
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/* Since s2 is less than 16 bytes, com_c is definitive
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determination of full match. */
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return (char *) p1 + cmp;
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}
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}
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/* General case, s2 is at least 16 bytes or more.
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First, the common case of false-match at first byte of p2. */
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pt = NULL;
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kmp_fwd = 0;
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const unsigned char *pt = NULL;
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int kmp_fwd = 0;
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re_trace:
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while (!cmp_c)
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{
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@ -378,11 +355,11 @@ re_trace:
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frag1 = strloadu (p1);
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/* Unsigned bytes, equal order, is there a partial match? */
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cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
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cmp = _mm_cmpistri(frag2, frag1, 0x0c);
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cmp_z = _mm_cmpistrz(frag2, frag1, 0x0c);
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cmp = _mm_cmpistri (frag2, frag1, 0x0c);
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cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c);
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}
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/* Next, handle inital positive match as first byte of p2. We have
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/* Next, handle initial positive match as first byte of p2. We have
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a partial fragment match, make full determination until we reached
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end of s2. */
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if (!cmp)
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@ -394,7 +371,7 @@ re_trace:
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p1 += 16;
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p2 += 16;
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/* Load up to 16 bytes of fragment. */
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frag2 = strloadu(p2);
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frag2 = strloadu (p2);
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}
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else
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{
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@ -426,7 +403,7 @@ re_trace:
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cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c);
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}
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/* Full determination yielded false result, retrace s1 to next
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/* Full determination yielded a false result, retrace s1 to next
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starting position.
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Zflg 1 0 1 0/1
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Sflg 0 1 1 0/1
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@ -435,18 +412,20 @@ re_trace:
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false match retrace s1 else false
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*/
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if(cmp_s & !cmp)
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if (cmp_s & !cmp)
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return (char *) pt;
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else if (cmp_z)
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if (cmp_z)
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{
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if (!cmp_s)
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return NULL;
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/* Handle both zero and sign flag set and s1 is shorter in
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length. */
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zero = _mm_setzero_si128 ();
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bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag2));
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bmsk1 = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag1));
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__m128i zero = _mm_setzero_si128 ();
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int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag2));
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int bmsk1 = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag1));
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int len;
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int len1;
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__asm ("bsfl %[bmsk], %[len]"
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: [len] "=r" (len) : [bmsk] "r" (bmsk));
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__asm ("bsfl %[bmsk1], %[len1]"
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@ -471,13 +450,11 @@ re_trace:
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/* Since s2 is at least 16 bytes long, we're certain there is no
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match. */
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if (!p1[0])
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if (p1[0] == '\0')
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return NULL;
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else
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{
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/* Load up to 16 bytes of fragment. */
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frag1 = strloadu (p1);
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}
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/* Unsigned bytes, equal order, is there a partial match? */
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cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c);
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