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Diffstat (limited to 'kernel/arch/nios2/lib/memset.c')
-rw-r--r-- | kernel/arch/nios2/lib/memset.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/kernel/arch/nios2/lib/memset.c b/kernel/arch/nios2/lib/memset.c new file mode 100644 index 000000000..65e97802f --- /dev/null +++ b/kernel/arch/nios2/lib/memset.c @@ -0,0 +1,81 @@ +/* + * 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> + +#ifdef __HAVE_ARCH_MEMSET +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 */ + : "r" (c), /* %5 Input */ + "0" (s), /* %0 Input/Output */ + "1" (count) /* %1 Input/Output */ + : "memory" /* clobbered */ + ); + + return s; +} +#endif /* __HAVE_ARCH_MEMSET */ |