RetroArch/libretro-common/conversion/float_to_s16_neon.S
2016-05-16 11:15:46 +02:00

57 lines
1.4 KiB
ArmAsm

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2014 - Hans-Kristian Arntzen
*
* RetroArch 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 Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RetroArch 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 RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
#if defined(__ARM_NEON__)
#ifndef __MACH__
.arm
#endif
.align 4
.globl convert_float_s16_asm
.globl _convert_float_s16_asm
# convert_float_s16_asm(int16_t *out, const float *in, size_t samples)
convert_float_s16_asm:
_convert_float_s16_asm:
# Hacky way to get a constant of 2^15.
# ((2^4)^2)^2 * 0.5 = 2^15
vmov.f32 q8, #16.0
vmov.f32 q9, #0.5
vmul.f32 q8, q8, q8
vmul.f32 q8, q8, q8
vmul.f32 q8, q8, q9
1:
# Preload here?
vld1.f32 {q0-q1}, [r1]!
vmul.f32 q0, q0, q8
vmul.f32 q1, q1, q8
vcvt.s32.f32 q0, q0
vcvt.s32.f32 q1, q1
vqmovn.s32 d4, q0
vqmovn.s32 d5, q1
vst1.f32 {d4-d5}, [r0]!
# Guaranteed to get samples in multiples of 8.
subs r2, r2, #8
bne 1b
bx lr
#endif