/* * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> * Copyright (C) 2004 Microtronix Datacom Ltd * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include <linux/types.h> #include <linux/string.h> void *memset(void *s, int c, size_t count) { int destptr, charcnt, dwordcnt, fill8reg, wrkrega; if (!count) return s; c &= 0xFF; if (count <= 8) { char *xs = (char *) s; while (count--) *xs++ = c; return s; } __asm__ __volatile__ ( /* fill8 %3, %5 (c & 0xff) */ " slli %4, %5, 8\n" " or %4, %4, %5\n" " slli %3, %4, 16\n" " or %3, %3, %4\n" /* Word-align %0 (s) if necessary */ " andi %4, %0, 0x01\n" " beq %4, zero, 1f\n" " addi %1, %1, -1\n" " stb %3, 0(%0)\n" " addi %0, %0, 1\n" "1: mov %2, %1\n" /* Dword-align %0 (s) if necessary */ " andi %4, %0, 0x02\n" " beq %4, zero, 2f\n" " addi %1, %1, -2\n" " sth %3, 0(%0)\n" " addi %0, %0, 2\n" " mov %2, %1\n" /* %1 and %2 are how many more bytes to set */ "2: srli %2, %2, 2\n" /* %2 is how many dwords to set */ "3: stw %3, 0(%0)\n" " addi %0, %0, 4\n" " addi %2, %2, -1\n" " bne %2, zero, 3b\n" /* store residual word and/or byte if necessary */ " andi %4, %1, 0x02\n" " beq %4, zero, 4f\n" " sth %3, 0(%0)\n" " addi %0, %0, 2\n" /* store residual byte if necessary */ "4: andi %4, %1, 0x01\n" " beq %4, zero, 5f\n" " stb %3, 0(%0)\n" "5:\n" : "=r" (destptr), /* %0 Output */ "=r" (charcnt), /* %1 Output */ "=r" (dwordcnt), /* %2 Output */ "=r" (fill8reg), /* %3 Output */ "=&r" (wrkrega) /* %4 Output only */ : "r" (c), /* %5 Input */ "0" (s), /* %0 Input/Output */ "1" (count) /* %1 Input/Output */ : "memory" /* clobbered */ ); return s; }