Date: Thu, 19 Aug 1999 07:54:41 -0700 (PDT) From: Peter Wemm <peter@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/include cpufunc.h Message-ID: <199908191454.HAA43931@freefall.freebsd.org>
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peter 1999/08/19 07:54:40 PDT
Modified files:
sys/i386/include cpufunc.h
Log:
Undo my previous commit and do it differently. Break the ffs() etc macros
into two parts - one to do the bsfl and the other to convert the result
(base 0) to ffs()-like (base 1) in inline C. This enables the optimizer
to be a lot smarter in certain cases, like where it knows that the argument
is non-zero and we want ffs(known non zero arg) - 1. This appears to
produce identical code to the old inline when the argument is unknown.
Revision Changes Path
1.90 +27 -14 src/sys/i386/include/cpufunc.h
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