Date: Sat, 31 Jan 2009 18:27:02 +0000 (UTC) From: David Schultz <das@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/include stdlib.h string.h wchar.h src/sys/sys cdefs.h malloc.h Message-ID: <200901311832.n0VIW8Ma016564@repoman.freebsd.org>
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das 2009-01-31 18:27:02 UTC
FreeBSD src repository
Modified files:
include stdlib.h string.h wchar.h
sys/sys cdefs.h malloc.h
Log:
SVN rev 187961 on 2009-01-31 18:27:02Z by das
Add a function attribute called `__malloc_like', which informs gcc
that the annotated function returns a pointer that doesn't alias any
extant pointer. This results in a 50%+ speedup in microbenchmarks such
as the following:
char *cp = malloc(1), *buf = malloc(BUF);
for (i = 0; i < BUF; i++) buf[i] = *cp;
In real programs, your mileage will vary. Note that gcc already
performs this optimization automatically for any function called
`malloc', `calloc', `strdup', or `strndup' unless -fno-builtins is
used.
Revision Changes Path
1.68 +2 -2 src/include/stdlib.h
1.28 +2 -2 src/include/string.h
1.47 +1 -1 src/include/wchar.h
1.97 +2 -0 src/sys/sys/cdefs.h
1.88 +2 -2 src/sys/sys/malloc.h
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