| Index: fusl/src/string/memset.c
|
| diff --git a/fusl/src/string/memset.c b/fusl/src/string/memset.c
|
| index f438b073ae099d69556a7ddb6a838973cb4b13d9..3bc1e2717c2207687641069d02fb9423e85f3f74 100644
|
| --- a/fusl/src/string/memset.c
|
| +++ b/fusl/src/string/memset.c
|
| @@ -1,86 +1,92 @@
|
| #include <string.h>
|
| #include <stdint.h>
|
|
|
| -void *memset(void *dest, int c, size_t n)
|
| -{
|
| - unsigned char *s = dest;
|
| - size_t k;
|
| +void* memset(void* dest, int c, size_t n) {
|
| + unsigned char* s = dest;
|
| + size_t k;
|
|
|
| - /* Fill head and tail with minimal branching. Each
|
| - * conditional ensures that all the subsequently used
|
| - * offsets are well-defined and in the dest region. */
|
| + /* Fill head and tail with minimal branching. Each
|
| + * conditional ensures that all the subsequently used
|
| + * offsets are well-defined and in the dest region. */
|
|
|
| - if (!n) return dest;
|
| - s[0] = s[n-1] = c;
|
| - if (n <= 2) return dest;
|
| - s[1] = s[n-2] = c;
|
| - s[2] = s[n-3] = c;
|
| - if (n <= 6) return dest;
|
| - s[3] = s[n-4] = c;
|
| - if (n <= 8) return dest;
|
| + if (!n)
|
| + return dest;
|
| + s[0] = s[n - 1] = c;
|
| + if (n <= 2)
|
| + return dest;
|
| + s[1] = s[n - 2] = c;
|
| + s[2] = s[n - 3] = c;
|
| + if (n <= 6)
|
| + return dest;
|
| + s[3] = s[n - 4] = c;
|
| + if (n <= 8)
|
| + return dest;
|
|
|
| - /* Advance pointer to align it at a 4-byte boundary,
|
| - * and truncate n to a multiple of 4. The previous code
|
| - * already took care of any head/tail that get cut off
|
| - * by the alignment. */
|
| + /* Advance pointer to align it at a 4-byte boundary,
|
| + * and truncate n to a multiple of 4. The previous code
|
| + * already took care of any head/tail that get cut off
|
| + * by the alignment. */
|
|
|
| - k = -(uintptr_t)s & 3;
|
| - s += k;
|
| - n -= k;
|
| - n &= -4;
|
| + k = -(uintptr_t)s & 3;
|
| + s += k;
|
| + n -= k;
|
| + n &= -4;
|
|
|
| #ifdef __GNUC__
|
| - typedef uint32_t __attribute__((__may_alias__)) u32;
|
| - typedef uint64_t __attribute__((__may_alias__)) u64;
|
| + typedef uint32_t __attribute__((__may_alias__)) u32;
|
| + typedef uint64_t __attribute__((__may_alias__)) u64;
|
|
|
| - u32 c32 = ((u32)-1)/255 * (unsigned char)c;
|
| + u32 c32 = ((u32)-1) / 255 * (unsigned char)c;
|
|
|
| - /* In preparation to copy 32 bytes at a time, aligned on
|
| - * an 8-byte bounary, fill head/tail up to 28 bytes each.
|
| - * As in the initial byte-based head/tail fill, each
|
| - * conditional below ensures that the subsequent offsets
|
| - * are valid (e.g. !(n<=24) implies n>=28). */
|
| + /* In preparation to copy 32 bytes at a time, aligned on
|
| + * an 8-byte bounary, fill head/tail up to 28 bytes each.
|
| + * As in the initial byte-based head/tail fill, each
|
| + * conditional below ensures that the subsequent offsets
|
| + * are valid (e.g. !(n<=24) implies n>=28). */
|
|
|
| - *(u32 *)(s+0) = c32;
|
| - *(u32 *)(s+n-4) = c32;
|
| - if (n <= 8) return dest;
|
| - *(u32 *)(s+4) = c32;
|
| - *(u32 *)(s+8) = c32;
|
| - *(u32 *)(s+n-12) = c32;
|
| - *(u32 *)(s+n-8) = c32;
|
| - if (n <= 24) return dest;
|
| - *(u32 *)(s+12) = c32;
|
| - *(u32 *)(s+16) = c32;
|
| - *(u32 *)(s+20) = c32;
|
| - *(u32 *)(s+24) = c32;
|
| - *(u32 *)(s+n-28) = c32;
|
| - *(u32 *)(s+n-24) = c32;
|
| - *(u32 *)(s+n-20) = c32;
|
| - *(u32 *)(s+n-16) = c32;
|
| + *(u32*)(s + 0) = c32;
|
| + *(u32*)(s + n - 4) = c32;
|
| + if (n <= 8)
|
| + return dest;
|
| + *(u32*)(s + 4) = c32;
|
| + *(u32*)(s + 8) = c32;
|
| + *(u32*)(s + n - 12) = c32;
|
| + *(u32*)(s + n - 8) = c32;
|
| + if (n <= 24)
|
| + return dest;
|
| + *(u32*)(s + 12) = c32;
|
| + *(u32*)(s + 16) = c32;
|
| + *(u32*)(s + 20) = c32;
|
| + *(u32*)(s + 24) = c32;
|
| + *(u32*)(s + n - 28) = c32;
|
| + *(u32*)(s + n - 24) = c32;
|
| + *(u32*)(s + n - 20) = c32;
|
| + *(u32*)(s + n - 16) = c32;
|
|
|
| - /* Align to a multiple of 8 so we can fill 64 bits at a time,
|
| - * and avoid writing the same bytes twice as much as is
|
| - * practical without introducing additional branching. */
|
| + /* Align to a multiple of 8 so we can fill 64 bits at a time,
|
| + * and avoid writing the same bytes twice as much as is
|
| + * practical without introducing additional branching. */
|
|
|
| - k = 24 + ((uintptr_t)s & 4);
|
| - s += k;
|
| - n -= k;
|
| + k = 24 + ((uintptr_t)s & 4);
|
| + s += k;
|
| + n -= k;
|
|
|
| - /* If this loop is reached, 28 tail bytes have already been
|
| - * filled, so any remainder when n drops below 32 can be
|
| - * safely ignored. */
|
| + /* If this loop is reached, 28 tail bytes have already been
|
| + * filled, so any remainder when n drops below 32 can be
|
| + * safely ignored. */
|
|
|
| - u64 c64 = c32 | ((u64)c32 << 32);
|
| - for (; n >= 32; n-=32, s+=32) {
|
| - *(u64 *)(s+0) = c64;
|
| - *(u64 *)(s+8) = c64;
|
| - *(u64 *)(s+16) = c64;
|
| - *(u64 *)(s+24) = c64;
|
| - }
|
| + u64 c64 = c32 | ((u64)c32 << 32);
|
| + for (; n >= 32; n -= 32, s += 32) {
|
| + *(u64*)(s + 0) = c64;
|
| + *(u64*)(s + 8) = c64;
|
| + *(u64*)(s + 16) = c64;
|
| + *(u64*)(s + 24) = c64;
|
| + }
|
| #else
|
| - /* Pure C fallback with no aliasing violations. */
|
| - for (; n; n--, s++) *s = c;
|
| + /* Pure C fallback with no aliasing violations. */
|
| + for (; n; n--, s++)
|
| + *s = c;
|
| #endif
|
|
|
| - return dest;
|
| + return dest;
|
| }
|
|
|