From ae612b04cc0716186e0d14e342bee184ba94ac1b Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 21 Jul 2009 07:52:12 -0700 Subject: Minor cleanups in x86-64 strstr. --- ChangeLog | 5 ++ sysdeps/x86_64/multiarch/strstr.c | 133 ++++++++++++++++---------------------- 2 files changed, 60 insertions(+), 78 deletions(-) diff --git a/ChangeLog b/ChangeLog index b107428a63..006dd5ac60 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2009-07-21 Ulrich Drepper + + * sysdeps/x86_64/multiarch/strstr.c: Minor cleanups. Remove + unnecesary variables. Comment fixes. + 2009-07-20 Ulrich Drepper * sysdeps/x86_64/multiarch/strstr.c [USE_AS_STRCASESTR] (STRSTR_SSE42): diff --git a/sysdeps/x86_64/multiarch/strstr.c b/sysdeps/x86_64/multiarch/strstr.c index f1455a1450..76d5ad16df 100644 --- a/sysdeps/x86_64/multiarch/strstr.c +++ b/sysdeps/x86_64/multiarch/strstr.c @@ -29,8 +29,7 @@ # include # define LOADBYTE(C) tolower (C) -# define CMPBYTE(C1, C2) \ - ((C1) == (C2) || tolower (C1) == tolower (C2)) +# define CMPBYTE(C1, C2) (tolower (C1) == tolower (C2)) #else # define LOADBYTE(C) (C) # define CMPBYTE(C1, C2) ((C1) == (C2)) @@ -222,16 +221,14 @@ static int __inline__ __attribute__ ((__always_inline__,)) KMP16Bovrlap (__m128i s2) { - __m128i a, b; - int bmsk, k1; - - b = _mm_unpacklo_epi8 (s2, s2); - a = _mm_unpacklo_epi8 (b, b); + __m128i b = _mm_unpacklo_epi8 (s2, s2); + __m128i a = _mm_unpacklo_epi8 (b, b); a = _mm_shuffle_epi32 (a, 0); 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); */ + int k1; __asm ("bsfl %[bmsk], %[k1]" : [k1] "=r" (k1) : [bmsk] "r" (bmsk)); if (!bmsk) return 16; @@ -256,31 +253,18 @@ char * __attribute__ ((section (".text.sse4.2"))) STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2) { - int len; - int len1; - const unsigned char *p1 = s1; +#define p1 s1 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; - if (!p1[0]) + if (p1[0] == '\0') return NULL; /* Check if p1 length is 1 byte long. */ - if (!p1[1]) - return !p2[1] && CMPBYTE (p1[0], p2[0]) ? (char *) p1 : NULL; + if (p1[1] == '\0') + return p2[1] == '\0' && CMPBYTE (p1[0], p2[0]) ? (char *) p1 : NULL; #ifdef USE_AS_STRCASESTR __m128i (*strloadu) (const unsigned char *); @@ -294,44 +278,39 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2) #endif /* p1 > 1 byte long. Load up to 16 bytes of fragment. */ - frag1 = strloadu (p1); + __m128i frag1 = strloadu (p1); - if (p2[1]) - { - /* p2 is > 1 byte long. */ - frag2 = strloadu (p2); - } + __m128i frag2; + if (p2[1] != '\0') + /* p2 is > 1 byte long. */ + frag2 = strloadu (p2); else - { - zero = _mm_setzero_si128 (); - frag2 = _mm_insert_epi8 (zero, LOADBYTE(p2[0]), 0); - } + frag2 = _mm_insert_epi8 (_mm_setzero_si128 (), LOADBYTE (p2[0]), 0); /* Unsigned bytes, equal order, does frag2 has null? */ - cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); - cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c); - cmp = _mm_cmpistri (frag2, frag1, 0x0c); - cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); + int cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); + int cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c); + int cmp = _mm_cmpistri (frag2, frag1, 0x0c); + int cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); if (cmp_s & cmp_c) { - zero = _mm_setzero_si128 (); - bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (frag2, zero)); + int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (frag2, + _mm_setzero_si128 ())); + int len; __asm ("bsfl %[bmsk], %[len]" : [len] "=r" (len) : [bmsk] "r" (bmsk)); p1 += cmp; if ((len + cmp) <= 16) return (char *) p1; - else - { - /* Load up to 16 bytes of fragment. */ - frag1 = strloadu (p1); - cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); - cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); - cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c); - cmp = _mm_cmpistri (frag2, frag1, 0x0c); - if ((len + cmp) <= 16) - return (char *) p1 + cmp; - } + + /* Load up to 16 bytes of fragment. */ + frag1 = strloadu (p1); + cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); + cmp_s = _mm_cmpistrs (frag2, frag1, 0x0c); + cmp_z = _mm_cmpistrz (frag2, frag1, 0x0c); + cmp = _mm_cmpistri (frag2, frag1, 0x0c); + if ((len + cmp) <= 16) + return (char *) p1 + cmp; } if (cmp_s) @@ -353,18 +332,16 @@ STRSTR_SSE42 (const unsigned char *s1, const unsigned char *s2) if (!cmp_c) return NULL; - else - { - /* Since s2 is less than 16 bytes, com_c is definitive - determination of full match. */ - return (char *) p1 + cmp; - } + + /* Since s2 is less than 16 bytes, com_c is definitive + determination of full match. */ + return (char *) p1 + cmp; } /* General case, s2 is at least 16 bytes or more. First, the common case of false-match at first byte of p2. */ - pt = NULL; - kmp_fwd = 0; + const unsigned char *pt = NULL; + int kmp_fwd = 0; re_trace: while (!cmp_c) { @@ -378,11 +355,11 @@ re_trace: frag1 = strloadu (p1); /* Unsigned bytes, equal order, is there a partial match? */ cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); - cmp = _mm_cmpistri(frag2, frag1, 0x0c); - cmp_z = _mm_cmpistrz(frag2, frag1, 0x0c); + cmp = _mm_cmpistri (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 end of s2. */ if (!cmp) @@ -394,7 +371,7 @@ re_trace: p1 += 16; p2 += 16; /* Load up to 16 bytes of fragment. */ - frag2 = strloadu(p2); + frag2 = strloadu (p2); } else { @@ -426,7 +403,7 @@ re_trace: 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. Zflg 1 0 1 0/1 Sflg 0 1 1 0/1 @@ -435,18 +412,20 @@ re_trace: false match retrace s1 else false */ - if(cmp_s & !cmp) + if (cmp_s & !cmp) return (char *) pt; - else if (cmp_z) + if (cmp_z) { if (!cmp_s) return NULL; /* Handle both zero and sign flag set and s1 is shorter in length. */ - zero = _mm_setzero_si128 (); - bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag2)); - bmsk1 = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag1)); + __m128i zero = _mm_setzero_si128 (); + int bmsk = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag2)); + int bmsk1 = _mm_movemask_epi8 (_mm_cmpeq_epi8 (zero, frag1)); + int len; + int len1; __asm ("bsfl %[bmsk], %[len]" : [len] "=r" (len) : [bmsk] "r" (bmsk)); __asm ("bsfl %[bmsk1], %[len1]" @@ -471,13 +450,11 @@ re_trace: /* Since s2 is at least 16 bytes long, we're certain there is no match. */ - if (!p1[0]) + if (p1[0] == '\0') return NULL; - else - { - /* Load up to 16 bytes of fragment. */ - frag1 = strloadu (p1); - } + + /* Load up to 16 bytes of fragment. */ + frag1 = strloadu (p1); /* Unsigned bytes, equal order, is there a partial match? */ cmp_c = _mm_cmpistrc (frag2, frag1, 0x0c); -- cgit v1.2.3