RetroArch/libretro-common/audio/conversion/float_to_s16_neon.c
2020-01-31 15:43:42 +01:00

65 lines
2.5 KiB
C

/* Copyright (C) 2010-2020 The RetroArch team
*
* ---------------------------------------------------------------------------------------
* The following license statement only applies to this file (float_to_s16_neon.S).
* ---------------------------------------------------------------------------------------
*
* Permission is hereby granted, free of charge,
* to any person obtaining a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#if defined(__ARM_NEON__) && !defined(DONT_WANT_ARM_OPTIMIZATIONS)
#if defined(__thumb__)
#define DECL_ARMMODE(x) " .align 2\n" " .global " x "\n" " .thumb\n" " .thumb_func\n" " .type " x ", %function\n" x ":\n"
#else
#define DECL_ARMMODE(x) " .align 4\n" " .global " x "\n" " .arm\n" x ":\n"
#endif
asm(
DECL_ARMMODE("convert_float_s16_asm")
DECL_ARMMODE("_convert_float_s16_asm")
"# convert_float_s16_asm(int16_t *out, const float *in, size_t samples)\n"
" # Hacky way to get a constant of 2^15.\n"
" # ((2^4)^2)^2 * 0.5 = 2^15\n"
" vmov.f32 q8, #16.0\n"
" vmov.f32 q9, #0.5\n"
" vmul.f32 q8, q8, q8\n"
" vmul.f32 q8, q8, q8\n"
" vmul.f32 q8, q8, q9\n"
"\n"
"1:\n"
" # Preload here?\n"
" vld1.f32 {q0-q1}, [r1]!\n"
"\n"
" vmul.f32 q0, q0, q8\n"
" vmul.f32 q1, q1, q8\n"
"\n"
" vcvt.s32.f32 q0, q0\n"
" vcvt.s32.f32 q1, q1\n"
"\n"
" vqmovn.s32 d4, q0\n"
" vqmovn.s32 d5, q1\n"
"\n"
" vst1.f32 {d4-d5}, [r0]!\n"
"\n"
" # Guaranteed to get samples in multiples of 8.\n"
" subs r2, r2, #8\n"
" bne 1b\n"
"\n"
" bx lr\n"
"\n"
);
#endif