Re: tweaking MemSet() performance - 7.4.5

On Wed, 2004-09-29 at 21:37, Bruce Momjian wrote:
> The reason MemSet is a win is not that the C code is great but because
> it eliminates a function call.

A reasonable compiler ought to be able to implement memset() as a
compiler intrinsic where it makes sense to do so. MSVC++ can certainly
do this; per the GCC 3.4 docs, it seems GCC can/does as well:

The ISO C90 functions abort, abs, acos, asin, atan2, atan, calloc, ceil,
cosh, cos, exit, exp, fabs, floor, fmod, fprintf, fputs, frexp, fscanf,
labs, ldexp, log10, log, malloc, memcmp, memcpy, memset, modf, pow,
printf, putchar, puts, scanf, sinh, sin, snprintf, sprintf, sqrt,
sscanf, strcat, strchr, strcmp, strcpy, strcspn, strlen, strncat,
strncmp, strncpy, strpbrk, strrchr, strspn, strstr, tanh, tan, vfprintf,
vprintf and vsprintf are all recognized as built-in functions unless
-fno-builtin is specified (or -fno-builtin-function is specified for an
individual function). All of these functions have corresponding versions
prefixed with __builtin_.

(http://gcc.gnu.org/onlinedocs/gcc-3.4.2/gcc/Other-Builtins.html#Other-Builtins)

-Neil