| /* |
| * 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) |
| { |
| 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; |
| } |