From 736e0419809e08bd4163e785f850619af4519b4d Mon Sep 17 00:00:00 2001 From: Peter Meerwald Date: Tue, 2 Jul 2013 14:06:04 +0200 Subject: [PATCH] sconv: avoid multiply in ARM NEON s16->float conversion Signed-off-by: Peter Meerwald --- src/pulsecore/sconv_neon.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/src/pulsecore/sconv_neon.c b/src/pulsecore/sconv_neon.c index 6f1a3c9f..071ba855 100644 --- a/src/pulsecore/sconv_neon.c +++ b/src/pulsecore/sconv_neon.c @@ -61,19 +61,14 @@ static void pa_sconv_s16le_from_f32ne_neon(unsigned n, const float *src, int16_t static void pa_sconv_s16le_to_f32ne_neon(unsigned n, const int16_t *src, float *dst) { unsigned i = n & 3; - const float invscale = 1.0f / (1 << 15); - __asm__ __volatile__ ( "movs %[n], %[n], lsr #2 \n\t" "beq 2f \n\t" - "vdup.f32 q1, %[invscale] \n\t" - "1: \n\t" "vld1.16 {d0}, [%[src]]! \n\t" "vmovl.s16 q0, d0 \n\t" /* widen */ - "vcvt.f32.s32 q0, q0 \n\t" /* f32<-s32 */ - "vmul.f32 q0, q0, q1 \n\t" + "vcvt.f32.s32 q0, q0, #15 \n\t" /* f32<-s32 and divide by (1<<15) */ "subs %[n], %[n], #1 \n\t" "vst1.32 {q0}, [%[dst]]! \n\t" "bgt 1b \n\t" @@ -81,11 +76,12 @@ static void pa_sconv_s16le_to_f32ne_neon(unsigned n, const int16_t *src, float * "2: \n\t" : [dst] "+r" (dst), [src] "+r" (src), [n] "+r" (n) /* output operands (or input operands that get modified) */ - : [invscale] "r" (invscale) /* input operands */ - : "memory", "cc", "q0", "q1" /* clobber list */ + : /* input operands */ + : "memory", "cc", "q0" /* clobber list */ ); /* leftovers */ + const float invscale = 1.0f / (1 << 15); while (i--) { *dst++ = *src++ * invscale; } -- 2.39.2