projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| eea9507a LFT |
1 | /* |
| 2 | * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> | |
| 3 | * Copyright (C) 2004 Microtronix Datacom Ltd | |
| 4 | * | |
| 5 | * This file is subject to the terms and conditions of the GNU General Public | |
| 6 | * License. See the file "COPYING" in the main directory of this archive | |
| 7 | * for more details. | |
| 8 | */ | |
| 9 | ||
| 10 | #include <linux/types.h> | |
| 11 | #include <linux/string.h> | |
| 12 | ||
| 13 | #ifdef __HAVE_ARCH_MEMSET | |
| 14 | void *memset(void *s, int c, size_t count) | |
| 15 | { | |
| 16 | int destptr, charcnt, dwordcnt, fill8reg, wrkrega; | |
| 17 | ||
| 18 | if (!count) | |
| 19 | return s; | |
| 20 | ||
| 21 | c &= 0xFF; | |
| 22 | ||
| 23 | if (count <= 8) { | |
| 24 | char *xs = (char *) s; | |
| 25 | ||
| 26 | while (count--) | |
| 27 | *xs++ = c; | |
| 28 | return s; | |
| 29 | } | |
| 30 | ||
| 31 | __asm__ __volatile__ ( | |
| 32 | /* fill8 %3, %5 (c & 0xff) */ | |
| 33 | " slli %4, %5, 8\n" | |
| 34 | " or %4, %4, %5\n" | |
| 35 | " slli %3, %4, 16\n" | |
| 36 | " or %3, %3, %4\n" | |
| 37 | /* Word-align %0 (s) if necessary */ | |
| 38 | " andi %4, %0, 0x01\n" | |
| 39 | " beq %4, zero, 1f\n" | |
| 40 | " addi %1, %1, -1\n" | |
| 41 | " stb %3, 0(%0)\n" | |
| 42 | " addi %0, %0, 1\n" | |
| 43 | "1: mov %2, %1\n" | |
| 44 | /* Dword-align %0 (s) if necessary */ | |
| 45 | " andi %4, %0, 0x02\n" | |
| 46 | " beq %4, zero, 2f\n" | |
| 47 | " addi %1, %1, -2\n" | |
| 48 | " sth %3, 0(%0)\n" | |
| 49 | " addi %0, %0, 2\n" | |
| 50 | " mov %2, %1\n" | |
| 51 | /* %1 and %2 are how many more bytes to set */ | |
| 52 | "2: srli %2, %2, 2\n" | |
| 53 | /* %2 is how many dwords to set */ | |
| 54 | "3: stw %3, 0(%0)\n" | |
| 55 | " addi %0, %0, 4\n" | |
| 56 | " addi %2, %2, -1\n" | |
| 57 | " bne %2, zero, 3b\n" | |
| 58 | /* store residual word and/or byte if necessary */ | |
| 59 | " andi %4, %1, 0x02\n" | |
| 60 | " beq %4, zero, 4f\n" | |
| 61 | " sth %3, 0(%0)\n" | |
| 62 | " addi %0, %0, 2\n" | |
| 63 | /* store residual byte if necessary */ | |
| 64 | "4: andi %4, %1, 0x01\n" | |
| 65 | " beq %4, zero, 5f\n" | |
| 66 | " stb %3, 0(%0)\n" | |
| 67 | "5:\n" | |
| 68 | : "=r" (destptr), /* %0 Output */ | |
| 69 | "=r" (charcnt), /* %1 Output */ | |
| 70 | "=r" (dwordcnt), /* %2 Output */ | |
| 71 | "=r" (fill8reg), /* %3 Output */ | |
| 72 | "=r" (wrkrega) /* %4 Output */ | |
| 73 | : "r" (c), /* %5 Input */ | |
| 74 | "0" (s), /* %0 Input/Output */ | |
| 75 | "1" (count) /* %1 Input/Output */ | |
| 76 | : "memory" /* clobbered */ | |
| 77 | ); | |
| 78 | ||
| 79 | return s; | |
| 80 | } | |
| 81 | #endif /* __HAVE_ARCH_MEMSET */ |