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Re: frexp function misoptimization
- From: Ian Lance Taylor <iant at google dot com>
- To: Jeremy Sanders <jss at ast dot cam dot ac dot uk>
- Cc: gcc-help at gcc dot gnu dot org
- Date: Fri, 07 Mar 2008 18:17:26 -0800
- Subject: Re: frexp function misoptimization
- References: <fqrb82$esm$1@ger.gmane.org>
Jeremy Sanders <jss@ast.cam.ac.uk> writes:
> I notice on x86_64 Linux with gcc-4.1.2, that if I make a call to frexp()
> from math.h, this function is not inlined in the assembly output
> (with -O2). I've tried -ffast-math as well.
>
> As this function could be trivially inlined (it's just a matter of getting
> the correct bits from the stored number), is this a gcc misoptimization or
> is glibc the culprit?
It's just that nobody got around to it. As it happens, inlining of
frexp is a new optimization in gcc 4.3.
Ian