Date: Tue, 3 Apr 2012 15:58:33 +0200 From: Thomas Mueller <tmueller@sysgo.com> To: Andrey Simonenko <simon@comsys.ntu-kpi.kiev.ua> Cc: freebsd-current@freebsd.org Subject: Re: -ffast-math in Ports and wrong generated code Message-ID: <20120403155833.2f084c75@tmu.ulm.sysgo.com> In-Reply-To: <20120403112111.GA39616@pm513-1.comsys.ntu-kpi.kiev.ua> References: <20120403112111.GA39616@pm513-1.comsys.ntu-kpi.kiev.ua>
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On Tue, 3 Apr 2012 14:21:11 +0300, Andrey Simonenko wrote:
> At least finite() function call was eliminated from the result Assembler
> code when -ffast-math option is used, tested on 9.0-STABLE and 10.0-CURRENT.
The documentation for -ffast-math once (GCC 3.x?) contained
-ffast-math
Might allow some programs designed to not be too dependent on IEEE
behavior for floating-point to run faster, or die trying.
which seems like what you're observing.
-ffast-math includes -ffinite-math-only which assumes that
floating-point arguments and results are never NaNs or +-Infs.
Compiling your code with "-ffast-math -fno-finite-math-only" should
restore the call to finite().
--
Thomas Mueller
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