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/*
DeaDBeeF - ultimate music player for GNU/Linux systems with X11
Copyright (C) 2009-2010 Alexey Yakovenko <waker@users.sourceforge.net>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef __OPTMATH_H
#define __OPTMATH_H
#include <math.h>
#ifdef __SSE2__ // that comes from -msse2
#define __FORCE_SSE2__
#endif
// some maths
// taken from vorbis/lib/os.h, (C) 1994-2007 Xiph.Org Foundation http://www.xiph.org/
/* Special i386 GCC implementation */
#if defined(__i386__) && defined(__GNUC__) && !defined(__BEOS__) && !defined(__FORCE_SSE2__)
# define FPU_CONTROL
/* both GCC and MSVC are kinda stupid about rounding/casting to int.
Because of encapsulation constraints (GCC can't see inside the asm
block and so we end up doing stupid things like a store/load that
is collectively a noop), we do it this way */
/* we must set up the fpu before this works!! */
typedef int16_t fpu_control;
static inline void fpu_setround(fpu_control *fpu){
int16_t ret;
int16_t temp;
__asm__ __volatile__("fnstcw %0\n\t"
"movw %0,%%dx\n\t"
"orw $62463,%%dx\n\t"
"movw %%dx,%1\n\t"
"fldcw %1\n\t":"=m"(ret):"m"(temp): "dx");
*fpu=ret;
}
static inline void fpu_restore(fpu_control fpu){
__asm__ __volatile__("fldcw %0":: "m"(fpu));
}
/* assumes the FPU is in round mode! */
static inline int ftoi(double f){ /* yes, double! Otherwise,
we get extra fst/fld to
truncate precision */
int i;
__asm__("fistl %0": "=m"(i) : "t"(f));
return(i);
}
#endif /* Special i386 GCC implementation */
/* MSVC inline assembly. 32 bit only; inline ASM isn't implemented in the
* 64 bit compiler */
#if defined(_MSC_VER) && !defined(_WIN64)
# define FPU_CONTROL
typedef int16_t fpu_control;
static __inline int ftoi(double f){
int i;
__asm{
fld f
fistp i
}
return i;
}
static __inline void fpu_setround(fpu_control *fpu){
}
static __inline void fpu_restore(fpu_control fpu){
}
#endif /* Special MSVC 32 bit implementation */
/* Optimized code path for x86_64 builds. Uses SSE2 intrinsics. This can be
done safely because all x86_64 CPUs supports SSE2. */
#if (defined(__FORCE_SSE2__)) || (defined(_MSC_VER) && defined(_WIN64)) || (defined(__GNUC__) && defined (__x86_64__))
#pragma warning "using sse2 for ftoi"
# define FPU_CONTROL
typedef int16_t fpu_control;
#include <emmintrin.h>
static __inline int ftoi(double f){
return _mm_cvtsd_si32(_mm_load_sd(&f));
}
static __inline void fpu_setround(fpu_control *fpu){
}
static __inline void fpu_restore(fpu_control fpu){
}
#endif /* Special MSVC x64 implementation */
/* If no special implementation was found for the current compiler / platform,
use the default implementation here: */
#ifndef FPU_CONTROL
typedef int fpu_control;
static int ftoi(double f){
/* Note: MSVC and GCC (at least on some systems) round towards zero, thus,
the floor() call is required to ensure correct roudning of
negative numbers */
return (int)floor(f+.5);
}
/* We don't have special code for this compiler/arch, so do it the slow way */
# define fpu_setround(fpu_control) {}
# define fpu_restore(fpu_control) {}
#endif /* default implementation */
#endif // __OPTMATH_H
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