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Diffstat (limited to 'libk3b/plugin/libsamplerate/float_cast.h')
| -rw-r--r-- | libk3b/plugin/libsamplerate/float_cast.h | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/libk3b/plugin/libsamplerate/float_cast.h b/libk3b/plugin/libsamplerate/float_cast.h new file mode 100644 index 0000000..af362e3 --- /dev/null +++ b/libk3b/plugin/libsamplerate/float_cast.h @@ -0,0 +1,203 @@ +/* +** Copyright (C) 2001-2003 Erik de Castro Lopo <erikd@mega-nerd.com> +** +** 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 Steet, Fifth Floor, Boston, MA 02110-1301, USA. +*/ + +/* Version 1.3 */ + + +/*============================================================================ +** On Intel Pentium processors (especially PIII and probably P4), converting +** from float to int is very slow. To meet the C specs, the code produced by +** most C compilers targeting Pentium needs to change the FPU rounding mode +** before the float to int conversion is performed. +** +** Changing the FPU rounding mode causes the FPU pipeline to be flushed. It +** is this flushing of the pipeline which is so slow. +** +** Fortunately the ISO C99 specifications define the functions lrint, lrintf, +** llrint and llrintf which fix this problem as a side effect. +** +** On Unix-like systems, the configure process should have detected the +** presence of these functions. If they weren't found we have to replace them +** here with a standard C cast. +*/ + +/* +** The C99 prototypes for lrint and lrintf are as follows: +** +** long int lrintf (float x) ; +** long int lrint (double x) ; +*/ + +#include "config.h" + +/* +** The presence of the required functions are detected during the configure +** process and the values HAVE_LRINT and HAVE_LRINTF are set accordingly in +** the config.h file. +*/ + +#define HAVE_LRINT_REPLACEMENT 0 + +#if (HAVE_LRINT && HAVE_LRINTF) + + /* + ** These defines enable functionality introduced with the 1999 ISO C + ** standard. They must be defined before the inclusion of math.h to + ** engage them. If optimization is enabled, these functions will be + ** inlined. With optimization switched off, you have to link in the + ** maths library using -lm. + */ + + #define _ISOC9X_SOURCE 1 + #define _ISOC99_SOURCE 1 + + #define __USE_ISOC9X 1 + #define __USE_ISOC99 1 + + #include <math.h> + +#elif (defined (WIN32) || defined (_WIN32)) + + #undef HAVE_LRINT_REPLACEMENT + #define HAVE_LRINT_REPLACEMENT 1 + #include <math.h> + + /* + ** Win32 doesn't seem to have these functions. + ** Therefore implement inline versions of these functions here. + */ + + __inline long int + lrint (double flt) + { int intgr; + + _asm + { fld flt + fistp intgr + } ; + + return intgr ; + } + + __inline long int + lrintf (float flt) + { int intgr; + + _asm + { fld flt + fistp intgr + } ; + + return intgr ; + } + +#elif (defined (__MWERKS__) && defined (macintosh)) + + /* This MacOS 9 solution was provided by Stephane Letz */ + + #undef HAVE_LRINT_REPLACEMENT + #define HAVE_LRINT_REPLACEMENT 1 + #include <math.h> + + #undef lrint + #undef lrintf + + #define lrint double2int + #define lrintf float2int + + inline int + float2int (register float in) + { long res [2] ; + + asm + { fctiw in,in + stfd in,res + } + return res [1] ; + } /* float2int */ + + inline int + double2int (register double in) + { long res [2] ; + + asm + { fctiw in,in + stfd in,res + } + return res [1] ; + } /* double2int */ + +#elif (defined (__MACH__) && defined (__APPLE__)) + + /* For Apple MacOSX. */ + + #undef HAVE_LRINT_REPLACEMENT + #define HAVE_LRINT_REPLACEMENT 1 + #include <math.h> + + #undef lrint + #undef lrintf + + #define lrint double2int + #define lrintf float2int + + inline static long int + float2int (register float in) + { int res [2] ; + + __asm__ __volatile__ + ( "fctiw %1, %1\n\t" + "stfd %1, %0" + : "=m" (res) /* Output */ + : "f" (in) /* Input */ + : "memory" + ) ; + + return res [1] ; + } /* lrintf */ + + inline static long int + double2int (register double in) + { int res [2] ; + + __asm__ __volatile__ + ( "fctiw %1, %1\n\t" + "stfd %1, %0" + : "=m" (res) /* Output */ + : "f" (in) /* Input */ + : "memory" + ) ; + + return res [1] ; + } /* lrint */ + +#else + #ifndef __sgi + #warning "Don't have the functions lrint() and lrintf()." + #warning "Replacing these functions with a standard C cast." + #endif + + #include <math.h> + + #define lrint(dbl) ((int) (dbl)) + #define lrintf(flt) ((int) (flt)) + +#endif + + + |