projects / wasi-libc.git / blame
| Commit | Line | Data |
|---|---|---|
| 320054e8 DG |
1 | #include <string.h> |
| 2 | #include <stdint.h> | |
| 3 | #include <endian.h> | |
| 4 | ||
| 5 | void *memcpy(void *restrict dest, const void *restrict src, size_t n) | |
| 6 | { | |
| 75fdabe1 CS |
7 | #if defined(__wasm_bulk_memory__) |
| 8 | return __builtin_memcpy(dest, src, n); | |
| 9 | #else | |
| 320054e8 DG |
10 | unsigned char *d = dest; |
| 11 | const unsigned char *s = src; | |
| 12 | ||
| 13 | #ifdef __GNUC__ | |
| 14 | ||
| 15 | #if __BYTE_ORDER == __LITTLE_ENDIAN | |
| 16 | #define LS >> | |
| 17 | #define RS << | |
| 18 | #else | |
| 19 | #define LS << | |
| 20 | #define RS >> | |
| 21 | #endif | |
| 22 | ||
| 23 | typedef uint32_t __attribute__((__may_alias__)) u32; | |
| 24 | uint32_t w, x; | |
| 25 | ||
| 26 | for (; (uintptr_t)s % 4 && n; n--) *d++ = *s++; | |
| 27 | ||
| 28 | if ((uintptr_t)d % 4 == 0) { | |
| 29 | for (; n>=16; s+=16, d+=16, n-=16) { | |
| 30 | *(u32 *)(d+0) = *(u32 *)(s+0); | |
| 31 | *(u32 *)(d+4) = *(u32 *)(s+4); | |
| 32 | *(u32 *)(d+8) = *(u32 *)(s+8); | |
| 33 | *(u32 *)(d+12) = *(u32 *)(s+12); | |
| 34 | } | |
| 35 | if (n&8) { | |
| 36 | *(u32 *)(d+0) = *(u32 *)(s+0); | |
| 37 | *(u32 *)(d+4) = *(u32 *)(s+4); | |
| 38 | d += 8; s += 8; | |
| 39 | } | |
| 40 | if (n&4) { | |
| 41 | *(u32 *)(d+0) = *(u32 *)(s+0); | |
| 42 | d += 4; s += 4; | |
| 43 | } | |
| 44 | if (n&2) { | |
| 45 | *d++ = *s++; *d++ = *s++; | |
| 46 | } | |
| 47 | if (n&1) { | |
| 48 | *d = *s; | |
| 49 | } | |
| 50 | return dest; | |
| 51 | } | |
| 52 | ||
| 53 | if (n >= 32) switch ((uintptr_t)d % 4) { | |
| 54 | case 1: | |
| 55 | w = *(u32 *)s; | |
| 56 | *d++ = *s++; | |
| 57 | *d++ = *s++; | |
| 58 | *d++ = *s++; | |
| 59 | n -= 3; | |
| 60 | for (; n>=17; s+=16, d+=16, n-=16) { | |
| 61 | x = *(u32 *)(s+1); | |
| 62 | *(u32 *)(d+0) = (w LS 24) | (x RS 8); | |
| 63 | w = *(u32 *)(s+5); | |
| 64 | *(u32 *)(d+4) = (x LS 24) | (w RS 8); | |
| 65 | x = *(u32 *)(s+9); | |
| 66 | *(u32 *)(d+8) = (w LS 24) | (x RS 8); | |
| 67 | w = *(u32 *)(s+13); | |
| 68 | *(u32 *)(d+12) = (x LS 24) | (w RS 8); | |
| 69 | } | |
| 70 | break; | |
| 71 | case 2: | |
| 72 | w = *(u32 *)s; | |
| 73 | *d++ = *s++; | |
| 74 | *d++ = *s++; | |
| 75 | n -= 2; | |
| 76 | for (; n>=18; s+=16, d+=16, n-=16) { | |
| 77 | x = *(u32 *)(s+2); | |
| 78 | *(u32 *)(d+0) = (w LS 16) | (x RS 16); | |
| 79 | w = *(u32 *)(s+6); | |
| 80 | *(u32 *)(d+4) = (x LS 16) | (w RS 16); | |
| 81 | x = *(u32 *)(s+10); | |
| 82 | *(u32 *)(d+8) = (w LS 16) | (x RS 16); | |
| 83 | w = *(u32 *)(s+14); | |
| 84 | *(u32 *)(d+12) = (x LS 16) | (w RS 16); | |
| 85 | } | |
| 86 | break; | |
| 87 | case 3: | |
| 88 | w = *(u32 *)s; | |
| 89 | *d++ = *s++; | |
| 90 | n -= 1; | |
| 91 | for (; n>=19; s+=16, d+=16, n-=16) { | |
| 92 | x = *(u32 *)(s+3); | |
| 93 | *(u32 *)(d+0) = (w LS 8) | (x RS 24); | |
| 94 | w = *(u32 *)(s+7); | |
| 95 | *(u32 *)(d+4) = (x LS 8) | (w RS 24); | |
| 96 | x = *(u32 *)(s+11); | |
| 97 | *(u32 *)(d+8) = (w LS 8) | (x RS 24); | |
| 98 | w = *(u32 *)(s+15); | |
| 99 | *(u32 *)(d+12) = (x LS 8) | (w RS 24); | |
| 100 | } | |
| 101 | break; | |
| 102 | } | |
| 103 | if (n&16) { | |
| 104 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 105 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 106 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 107 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 108 | } | |
| 109 | if (n&8) { | |
| 110 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 111 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 112 | } | |
| 113 | if (n&4) { | |
| 114 | *d++ = *s++; *d++ = *s++; *d++ = *s++; *d++ = *s++; | |
| 115 | } | |
| 116 | if (n&2) { | |
| 117 | *d++ = *s++; *d++ = *s++; | |
| 118 | } | |
| 119 | if (n&1) { | |
| 120 | *d = *s; | |
| 121 | } | |
| 122 | return dest; | |
| 123 | #endif | |
| 124 | ||
| 125 | for (; n; n--) *d++ = *s++; | |
| 126 | return dest; | |
| 75fdabe1 | 127 | #endif // __wasm_bulk_memory__ |
| 320054e8 | 128 | } |