| /* |
| FUNCTION |
| <<memset>>---set an area of memory |
| |
| INDEX |
| memset |
| |
| ANSI_SYNOPSIS |
| #include <string.h> |
| void *memset(void *<[dst]>, int <[c]>, size_t <[length]>); |
| |
| TRAD_SYNOPSIS |
| #include <string.h> |
| void *memset(<[dst]>, <[c]>, <[length]>) |
| void *<[dst]>; |
| int <[c]>; |
| size_t <[length]>; |
| |
| DESCRIPTION |
| This function converts the argument <[c]> into an unsigned |
| char and fills the first <[length]> characters of the array |
| pointed to by <[dst]> to the value. |
| |
| RETURNS |
| <<memset>> returns the value of <[dst]>. |
| |
| PORTABILITY |
| <<memset>> is ANSI C. |
| |
| <<memset>> requires no supporting OS subroutines. |
| |
| QUICKREF |
| memset ansi pure |
| */ |
| |
| /* |
| * The body of this function should not appear in PNaCl bitcode. |
| * We use PNACL_BITCODE instead of __le32__ or __pnacl__ since this |
| * should also apply to biased bitcode. |
| * See https://code.google.com/p/nativeclient/issues/detail?id=3493 |
| */ |
| #ifndef PNACL_BITCODE |
| |
| #include <string.h> |
| #include "local.h" |
| |
| #define LBLOCKSIZE (sizeof(long)) |
| #define UNALIGNED(X) ((long)X & (LBLOCKSIZE - 1)) |
| #define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE) |
| |
| _PTR |
| __inhibit_loop_to_libcall |
| _DEFUN (memset, (m, c, n), |
| _PTR m _AND |
| int c _AND |
| size_t n) |
| { |
| char *s = (char *) m; |
| |
| #if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__) |
| int i; |
| unsigned long buffer; |
| unsigned long *aligned_addr; |
| unsigned int d = c & 0xff; /* To avoid sign extension, copy C to an |
| unsigned variable. */ |
| |
| while (UNALIGNED (s)) |
| { |
| if (n--) |
| *s++ = (char) c; |
| else |
| return m; |
| } |
| |
| if (!TOO_SMALL (n)) |
| { |
| /* If we get this far, we know that n is large and s is word-aligned. */ |
| aligned_addr = (unsigned long *) s; |
| |
| /* Store D into each char sized location in BUFFER so that |
| we can set large blocks quickly. */ |
| buffer = (d << 8) | d; |
| buffer |= (buffer << 16); |
| for (i = 32; i < LBLOCKSIZE * 8; i <<= 1) |
| buffer = (buffer << i) | buffer; |
| |
| /* Unroll the loop. */ |
| while (n >= LBLOCKSIZE*4) |
| { |
| *aligned_addr++ = buffer; |
| *aligned_addr++ = buffer; |
| *aligned_addr++ = buffer; |
| *aligned_addr++ = buffer; |
| n -= 4*LBLOCKSIZE; |
| } |
| |
| while (n >= LBLOCKSIZE) |
| { |
| *aligned_addr++ = buffer; |
| n -= LBLOCKSIZE; |
| } |
| /* Pick up the remainder with a bytewise loop. */ |
| s = (char*)aligned_addr; |
| } |
| |
| #endif /* not PREFER_SIZE_OVER_SPEED */ |
| |
| while (n--) |
| *s++ = (char) c; |
| |
| return m; |
| } |
| |
| #endif /* PNACL_BITCODE */ |