/* * strlen.c -- strlen function. On at least some MIPS chips, a simple * strlen is faster than the 'optimized' C version. * * Copyright (c) 2001, 2002 Red Hat, Inc. * * The authors hereby grant permission to use, copy, modify, distribute, * and license this software and its documentation for any purpose, provided * that existing copyright notices are retained in all copies and that this * notice is included verbatim in any distributions. No written agreement, * license, or royalty fee is required for any of the authorized uses. * Modifications to this software may be copyrighted by their authors * and need not follow the licensing terms described here, provided that * the new terms are clearly indicated on the first page of each file where * they apply. */ #include #include /* MIPS16 needs to come first. */ #if defined(__mips16) size_t strlen (const char *str) { const char *start = str; while (*str++ != '\0') ; return str - start - 1; } #elif defined(__mips64) __asm__("" /* 64-bit MIPS targets */ " .set noreorder\n" " .set nomacro\n" " .globl strlen\n" " .ent strlen\n" "strlen:\n" " daddiu $2,$4,1\n" "\n" "1: lbu $3,0($4)\n" " bnez $3,1b\n" " daddiu $4,$4,1\n" "\n" " jr $31\n" " dsubu $2,$4,$2\n" " .end strlen\n" " .set macro\n" " .set reorder\n"); #else __asm__("" /* 32-bit MIPS targets */ " .set noreorder\n" " .set nomacro\n" " .globl strlen\n" " .ent strlen\n" "strlen:\n" " addiu $2,$4,1\n" "\n" "1: lbu $3,0($4)\n" " bnez $3,1b\n" " addiu $4,$4,1\n" "\n" " jr $31\n" " subu $2,$4,$2\n" " .end strlen\n" " .set macro\n" " .set reorder\n"); #endif
