beetle-pce-fast-libretro/mednafen/math_ops.h
2016-08-06 16:38:45 +02:00

21 lines
1.0 KiB
C

#ifndef __MDFN_MATH_OPS_H
#define __MDFN_MATH_OPS_H
// Some compilers' optimizers and some platforms might fubar the generated code from these macros,
// so some tests are run in...tests.cpp
#define sign_8_to_s16(_value) ((int16)(int8)(_value))
#define sign_9_to_s16(_value) (((int16)((unsigned int)(_value) << 7)) >> 7)
#define sign_10_to_s16(_value) (((int16)((uint32)(_value) << 6)) >> 6)
#define sign_11_to_s16(_value) (((int16)((uint32)(_value) << 5)) >> 5)
#define sign_12_to_s16(_value) (((int16)((uint32)(_value) << 4)) >> 4)
#define sign_13_to_s16(_value) (((int16)((uint32)(_value) << 3)) >> 3)
#define sign_14_to_s16(_value) (((int16)((uint32)(_value) << 2)) >> 2)
#define sign_15_to_s16(_value) (((int16)((uint32)(_value) << 1)) >> 1)
// This obviously won't convert higher-than-32 bit numbers to signed 32-bit ;)
// Also, this shouldn't be used for 8-bit and 16-bit signed numbers, since you can
// convert those faster with typecasts...
#define sign_x_to_s32(_bits, _value) (((int32)((uint32)(_value) << (32 - _bits))) >> (32 - _bits))
#endif