RetroArch/audio/utils_neon.S
2013-02-08 14:28:25 +01:00

87 lines
2.1 KiB
ArmAsm

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2013 - 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/>.
*/
.arm
.align 4
.global audio_convert_s16_float_asm
# audio_convert_s16_float_asm(float *out, const int16_t *in, size_t samples)
audio_convert_s16_float_asm:
# Hacky way to get a constant of 2^-15.
# Might be faster to just load a constant from memory.
# It's just done once however ...
vmov.f32 q8, #0.25
vmul.f32 q8, q8, q8
vmul.f32 q8, q8, q8
vmul.f32 q8, q8, q8
vadd.f32 q8, q8, q8
1:
# Preload here?
vld1.s16 {q0}, [r1]!
# Widen to 32-bit
vmovl.s16 q1, d0
vmovl.s16 q2, d1
# Convert to float
vcvt.f32.s32 q1, q1
vcvt.f32.s32 q2, q2
vmul.f32 q1, q1, q8
vmul.f32 q2, q2, q8
vst1.f32 {q1-q2}, [r0]!
# Guaranteed to get samples in multiples of 8.
subs r2, r2, #8
bne 1b
bx lr
.align 4
.global audio_convert_float_s16_asm
# audio_convert_float_s16_asm(int16_t *out, const float *in, size_t samples)
audio_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