mirrors/pulseaudio
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/pulseaudio/pulseaudio.git synced 2025-11-07 13:30:03 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

sconv: Fix NEON sconv rounding code

Browse source 
Rounding with 0.5 causes us to always round up for any value of the form
x.5. IEEE754 specifies round-to-nearest-even as the behaviour in this
case. This might not always be possible with NEON code, but this change
gets us much closer to it.
This commit is contained in:
Arun Raghavan 2012-10-26 16:36:49 +05:30
parent f558327cca
commit 1a8ec3c3e0
1 changed files with 3 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

10
src/pulsecore/sconv_neon.c
View file

@ -40,18 +40,14 @@ static void pa_sconv_s16le_from_f32ne_neon(unsigned n, const float *src, int16_t
"vneg.f32 q3, q2 \n\t" "vneg.f32 q3, q2 \n\t"
"vdup.f32 q4, %[scale] \n\t" "vdup.f32 q4, %[scale] \n\t"
"vdup.u32 q5, %[mask] \n\t" "vdup.u32 q5, %[mask] \n\t"
"vdup.f32 q6, %[half] \n\t"
"1: \n\t" "1: \n\t"
"vld1.32 {q0}, [%[src]]! \n\t" "vld1.32 {q0}, [%[src]]! \n\t"
"vmin.f32 q0, q0, q2 \n\t" /* clamp */ "vmin.f32 q0, q0, q2 \n\t" /* clamp */
"vmax.f32 q0, q0, q3 \n\t" "vmax.f32 q0, q0, q3 \n\t"
"vmul.f32 q0, q0, q4 \n\t" /* scale */ "vmul.f32 q0, q0, q4 \n\t" /* scale */
"vand.u32 q1, q0, q5 \n\t" "vcvt.s32.f32 q0, q0, #16 \n\t" /* narrow */
"vorr.u32 q1, q1, q6 \n\t" /* round */ "vrshrn.s32 d0, q0, #16 \n\t"
"vadd.f32 q0, q0, q1 \n\t"
"vcvt.s32.f32 q0, q0 \n\t" /* narrow */
"vmovn.i32 d0, q0 \n\t"
"subs %[n], %[n], #1 \n\t" "subs %[n], %[n], #1 \n\t"
"vst1.16 {d0}, [%[dst]]! \n\t" "vst1.16 {d0}, [%[dst]]! \n\t"
"bgt 1b \n\t" "bgt 1b \n\t"
@ -59,7 +55,7 @@ static void pa_sconv_s16le_from_f32ne_neon(unsigned n, const float *src, int16_t
"2: \n\t" "2: \n\t"
: [dst] "+r" (dst), [src] "+r" (src), [n] "+r" (n) /* output operands (or input operands that get modified) */ : [dst] "+r" (dst), [src] "+r" (src), [n] "+r" (n) /* output operands (or input operands that get modified) */
: [plusone] "r" (1.0f), [scale] "r" (32767.0f), [half] "r" (0.5f), [mask] "r" (0x80000000) /* input operands */ : [plusone] "r" (1.0f), [scale] "r" (32767.0f), [mask] "r" (0x80000000) /* input operands */
: "memory", "cc", "q0", "q1", "q2", "q3", "q4", "q5", "q6" /* clobber list */ : "memory", "cc", "q0", "q1", "q2", "q3", "q4", "q5", "q6" /* clobber list */
); );