Date: Wed, 13 Jun 2007 06:17:48 +0000 (UTC) From: Bruce Evans <bde@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/libkern mcount.c Message-ID: <200706130617.l5D6HncF038605@repoman.freebsd.org>
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bde 2007-06-13 06:17:48 UTC
FreeBSD src repository
Modified files:
sys/libkern mcount.c
Log:
Unbreak high resolution profiling a little: use dummy asms to prevent
timing loops being optimized away.
Once apon a time, gcc promised not to optimize away timing loops, but
gcc started optimizing away the call to a null function in the timing
loop here some time between gcc-3.3.3 and gcc-3.4.6, and it started
optimizing away the timing loop itself some time between gcc-3.4.6
and gcc-4.2.
Revision Changes Path
1.24 +6 -1 src/sys/libkern/mcount.c
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