view src/libm/s_fabs.c @ 5029:5d7d48157be7

Greg Jandl to SDL I did some digging, and I think I've found a better solution. By including some additional .m4 macros in the acinclude directory (http://www.gnu.org/software/autoconf-archive/ax_check_compiler_flags.html, http://www.gnu.org/software/autoconf-archive/ax_gcc_archflag.html and http://www.gnu.org/software/autoconf-archive/ax_gcc_x86_cpuid.html) then using the patch below (same as previous patch + one line change to configure.in), SDL will build correctly out of the box. The arch can then be overridden by --with-gcc-arch=<arch> (most will probably want to build with i686 there for general distribution) or --without-gcc-arch, to disable setting the arch all together. On my Atom netbook, I get -march=PentiumPro by default, which works great, as does --with-gcc-arch=i686.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 18 Jan 2011 22:40:45 -0800
parents dc1eb82ffdaa
children
line wrap: on
line source

/* @(#)s_fabs.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static const char rcsid[] =
    "$NetBSD: s_fabs.c,v 1.7 1995/05/10 20:47:13 jtc Exp $";
#endif

/*
 * fabs(x) returns the absolute value of x.
 */

#include "math.h"
#include "math_private.h"

libm_hidden_proto(fabs)
#ifdef __STDC__
     double fabs(double x)
#else
     double fabs(x)
     double x;
#endif
{
    u_int32_t high;
    GET_HIGH_WORD(high, x);
    SET_HIGH_WORD(x, high & 0x7fffffff);
    return x;
}

libm_hidden_def(fabs)