This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: [PATCH][libm] Replace global constants with preprocessor defines

From: Florian Weimer <fweimer at redhat dot com>
To: libc-alpha at sourceware dot org
Date: Tue, 08 Jan 2013 10:19:58 +0100
Subject: Re: [PATCH][libm] Replace global constants with preprocessor defines
References: <20121226074532.GB10003@spoyarek.pnq.redhat.com>

On 12/26/2012 08:45 AM, Siddhesh Poyarekar wrote:

A lot of constants (including 1.0 and 0.0) are encoded as `struct
number`.  This adds an extra dereference in the code and hence makes
it slower.

This might have been done to cut down constant pool references on RISC CPUs (ppc64 might qualify). Hopefully, current GCC can perform this optimization where beneficial.

--
Florian Weimer / Red Hat Product Security Team

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]