/* * Copyright (c) 2017 Imagination Technologies. * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with * the distribution. * * Neither the name of Imagination Technologies nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include <string.h> #define op_t unsigned long int #define op_size sizeof (op_t) #if __mips64 typedef struct { op_t B0:8, B1:8, B2:8, B3:8, B4:8, B5:8, B6:8, B7:8; } bits_t; #else typedef struct { op_t B0:8, B1:8, B2:8, B3:8; } bits_t; #endif typedef union { op_t v; bits_t b; } bitfields_t; #define DO_BYTE(i) \ if (a.b.B##i != ch) { \ if(a.b.B##i == '\0') return 0; \ p++; \ } else \ return (char *)p; #define DO_WORD(w, cnt) { \ op_t val = w[cnt] ^ mask_c; \ if ((((w[cnt] - mask_1) & ~w[cnt]) & mask_128) || \ (((val - mask_1) & ~val) & mask_128)) { \ return do_bytes(w + cnt, ch); \ } \ } static inline char * __attribute__ ((always_inline)) do_bytes (const op_t* w, unsigned char ch) { bitfields_t a; unsigned char* p = (unsigned char *) w; a.v = *w; #if __mips64 DO_BYTE(0) DO_BYTE(1) DO_BYTE(2) DO_BYTE(3) DO_BYTE(4) DO_BYTE(5) DO_BYTE(6) DO_BYTE(7) #else DO_BYTE(0) DO_BYTE(1) DO_BYTE(2) DO_BYTE(3) #endif return (char *)p; } char* strchr(const char* s, int c) __overloadable { const op_t *w; op_t mask_1, mask_128, mask_c; const unsigned char ch = c; unsigned char* p = (unsigned char *) s; /* * Check byte by byte till initial alignment */ for ( ; *p != ch && ((size_t) p % op_size) != 0; p++) if (*p == '\0') return 0; if (*p != ch) { w = (const op_t *) p; mask_c = ch | (ch << 8); mask_c |= mask_c << 16; __asm__ volatile ( "li %0, 0x01010101 \n\t" : "=r" (mask_1) ); #if __mips64 mask_1 |= mask_1 << 32; mask_c |= mask_c << 32; #endif mask_128 = mask_1 << 7; /* * Check word/dword wize after initial alignment till character match * or end of string */ while (1) { DO_WORD(w, 0) DO_WORD(w, 1) DO_WORD(w, 2) DO_WORD(w, 3) w += 4; } } return (char *)p; }