From e66e8464183e9916b248a9dedd4d6dcf3e1a38fa Mon Sep 17 00:00:00 2001 From: Peter Meerwald Date: Mon, 4 Feb 2013 01:30:19 +0100 Subject: [PATCH] sconv: Change/fix conversion to/from float32 use (1<<15) instead of 0x7fff as a factor when converting from s16 to float32 use (1<<31) instead of 0x7fffffff as a factor when converting from s32 to float32 the change is motivated by the following desireable properties: * s16_from_f32(f32_from_s16(x)) == x for all possible s16 values * x / (1.0f << 15) == x * (1.0f / (1 << 15)) for all x in s16 above changes enable easier optimization while guaranteeing bit-exact results further, other audio sample conversion code (libavresample) does it the same way v3 (comments Tanu): * fix saturation in pa_sconv_s16le_from_f32ne_neon(), use vqrshrn v2 (comments Tanu): * fix comments in ARM NEON code * use llrintf() in pa_sconv_s32le_from_float32ne() Signed-off-by: Peter Meerwald Cc: Tanu Kaskinen --- src/pulsecore/sconv-s16le.c | 84 ++++++++++++++++--------------------- src/pulsecore/sconv_neon.c | 25 +++++------ src/pulsecore/sconv_sse.c | 66 ++++++++++++++--------------- 3 files changed, 79 insertions(+), 96 deletions(-) diff --git a/src/pulsecore/sconv-s16le.c b/src/pulsecore/sconv-s16le.c index 138e4185..45cf9729 100644 --- a/src/pulsecore/sconv-s16le.c +++ b/src/pulsecore/sconv-s16le.c @@ -85,11 +85,11 @@ void pa_sconv_s16le_to_float32ne(unsigned n, const int16_t *a, float *b) { #if SWAP_WORDS == 1 for (; n > 0; n--) { int16_t s = *(a++); - *(b++) = ((float) INT16_FROM(s))/(float) 0x7FFF; + *(b++) = INT16_FROM(s) * (1.0f / (1 << 15)); } #else for (; n > 0; n--) - *(b++) = ((float) (*(a++)))/(float) 0x7FFF; + *(b++) = *(a++) * (1.0f / (1 << 15)); #endif } @@ -100,11 +100,11 @@ void pa_sconv_s32le_to_float32ne(unsigned n, const int32_t *a, float *b) { #if SWAP_WORDS == 1 for (; n > 0; n--) { int32_t s = *(a++); - *(b++) = (float) (((double) INT32_FROM(s))/0x7FFFFFFF); + *(b++) = INT32_FROM(s) * (1.0f / (1U << 31)); } #else for (; n > 0; n--) - *(b++) = (float) (((double) (*(a++)))/0x7FFFFFFF); + *(b++) = *(a++) * (1.0f / (1U << 31)); #endif } @@ -115,18 +115,16 @@ void pa_sconv_s16le_from_float32ne(unsigned n, const float *a, int16_t *b) { #if SWAP_WORDS == 1 for (; n > 0; n--) { int16_t s; - float v = *(a++); + float v = *(a++) * (1 << 15); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.f); - s = (int16_t) lrintf(v * 0x7FFF); + s = (int16_t) PA_CLAMP_UNLIKELY(lrintf(v), -0x8000, 0x7FFF); *(b++) = INT16_TO(s); } #else for (; n > 0; n--) { - float v = *(a++); + float v = *(a++) * (1 << 15); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.f); - *(b++) = (int16_t) lrintf(v * 0x7FFF); + *(b++) = (int16_t) PA_CLAMP_UNLIKELY(lrintf(v), -0x8000, 0x7FFF); } #endif } @@ -138,18 +136,16 @@ void pa_sconv_s32le_from_float32ne(unsigned n, const float *a, int32_t *b) { #if SWAP_WORDS == 1 for (; n > 0; n--) { int32_t s; - float v = *(a++); + float v = *(a++) * (1U << 31); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int32_t) lrint((double) v * (double) 0x7FFFFFFF); + s = (int32_t) PA_CLAMP_UNLIKELY(llrintf(v), -0x80000000LL, 0x7FFFFFFFLL); *(b++) = INT32_TO(s); } #else for (; n > 0; n--) { - float v = *(a++); + float v = *(a++) * (1U << 31); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - *(b++) = (int32_t) lrint((double) v * (double) 0x7FFFFFFF); + *(b++) = (int32_t) PA_CLAMP_UNLIKELY(llrintf(v), -0x80000000LL, 0x7FFFFFFFLL); } #endif } @@ -160,7 +156,7 @@ void pa_sconv_s16le_to_float32re(unsigned n, const int16_t *a, float *b) { for (; n > 0; n--) { int16_t s = *(a++); - float k = ((float) INT16_FROM(s))/0x7FFF; + float k = INT16_FROM(s) * (1.0f / (1 << 15)); k = PA_FLOAT32_SWAP(k); *(b++) = k; } @@ -172,7 +168,7 @@ void pa_sconv_s32le_to_float32re(unsigned n, const int32_t *a, float *b) { for (; n > 0; n--) { int32_t s = *(a++); - float k = (float) (((double) INT32_FROM(s))/0x7FFFFFFF); + float k = INT32_FROM(s) * (1.0f / (1U << 31)); k = PA_FLOAT32_SWAP(k); *(b++) = k; } @@ -185,9 +181,8 @@ void pa_sconv_s16le_from_float32re(unsigned n, const float *a, int16_t *b) { for (; n > 0; n--) { int16_t s; float v = *(a++); - v = PA_FLOAT32_SWAP(v); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int16_t) lrintf(v * 0x7FFF); + v = PA_FLOAT32_SWAP(v) * (1 << 15); + s = (int16_t) PA_CLAMP_UNLIKELY(lrintf(v), -0x8000, 0x7FFF); *(b++) = INT16_TO(s); } } @@ -199,9 +194,8 @@ void pa_sconv_s32le_from_float32re(unsigned n, const float *a, int32_t *b) { for (; n > 0; n--) { int32_t s; float v = *(a++); - v = PA_FLOAT32_SWAP(v); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int32_t) lrint((double) v * 0x7FFFFFFF); + v = PA_FLOAT32_SWAP(v) * (1U << 31); + s = (int32_t) PA_CLAMP_UNLIKELY(llrintf(v), -0x80000000LL, 0x7FFFFFFFLL); *(b++) = INT32_TO(s); } } @@ -304,9 +298,9 @@ void pa_sconv_s24le_to_float32ne(unsigned n, const uint8_t *a, float *b) { for (; n > 0; n--) { int32_t s = READ24(a) << 8; - *b = ((float) s) / 0x7FFFFFFF; + *b = s * (1.0f / (1U << 31)); a += 3; - b ++; + b++; } } @@ -316,12 +310,11 @@ void pa_sconv_s24le_from_float32ne(unsigned n, const float *a, uint8_t *b) { for (; n > 0; n--) { int32_t s; - float v = *a; - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int32_t) lrint((double) v * (double) 0x7FFFFFFF); + float v = *a * (1U << 31); + s = (int32_t) PA_CLAMP_UNLIKELY(llrint(v), -0x80000000LL, 0x7FFFFFFFLL); WRITE24(b, ((uint32_t) s) >> 8); a++; - b+=3; + b += 3; } } @@ -331,10 +324,10 @@ void pa_sconv_s24le_to_float32re(unsigned n, const uint8_t *a, float *b) { for (; n > 0; n--) { int32_t s = READ24(a) << 8; - float k = ((float) s) / 0x7FFFFFFF; + float k = s * (1.0f / (1U << 31)); *b = PA_FLOAT32_SWAP(k); a += 3; - b ++; + b++; } } @@ -345,9 +338,8 @@ void pa_sconv_s24le_from_float32re(unsigned n, const float *a, uint8_t *b) { for (; n > 0; n--) { int32_t s; float v = *a; - v = PA_FLOAT32_SWAP(v); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int32_t) lrint((double) v * (double) 0x7FFFFFFF); + v = PA_FLOAT32_SWAP(v) * (1U << 31); + s = (int32_t) PA_CLAMP_UNLIKELY(llrint(v), -0x80000000LL, 0x7FFFFFFFLL); WRITE24(b, ((uint32_t) s) >> 8); a++; b+=3; @@ -406,9 +398,9 @@ void pa_sconv_s24_32le_to_float32ne(unsigned n, const uint32_t *a, float *b) { for (; n > 0; n--) { int32_t s = (int32_t) (UINT32_FROM(*a) << 8); - *b = (float) s / (float) 0x7FFFFFFF; - a ++; - b ++; + *b = s * (1.0f / (1U << 31)); + a++; + b++; } } @@ -418,10 +410,10 @@ void pa_sconv_s24_32le_to_float32re(unsigned n, const uint32_t *a, float *b) { for (; n > 0; n--) { int32_t s = (int32_t) (UINT32_FROM(*a) << 8); - float k = (float) s / (float) 0x7FFFFFFF; + float k = s * (1.0f / (1U << 31)); *b = PA_FLOAT32_SWAP(k); - a ++; - b ++; + a++; + b++; } } @@ -431,9 +423,8 @@ void pa_sconv_s24_32le_from_float32ne(unsigned n, const float *a, uint32_t *b) { for (; n > 0; n--) { int32_t s; - float v = *a; - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int32_t) lrint((double) v * (double) 0x7FFFFFFF); + float v = *a * (1U << 31); + s = (int32_t) PA_CLAMP_UNLIKELY(llrint(v), -0x80000000LL, 0x7FFFFFFFLL); *b = UINT32_TO(((uint32_t) s) >> 8); a++; b++; @@ -447,9 +438,8 @@ void pa_sconv_s24_32le_from_float32re(unsigned n, const float *a, uint32_t *b) { for (; n > 0; n--) { int32_t s; float v = *a; - v = PA_FLOAT32_SWAP(v); - v = PA_CLAMP_UNLIKELY(v, -1.0f, 1.0f); - s = (int32_t) lrint((double) v * (double) 0x7FFFFFFF); + v = PA_FLOAT32_SWAP(v) * (1U << 31); + s = (int32_t) PA_CLAMP_UNLIKELY(llrint(v), -0x80000000LL, 0x7FFFFFFFLL); *b = UINT32_TO(((uint32_t) s) >> 8); a++; b++; diff --git a/src/pulsecore/sconv_neon.c b/src/pulsecore/sconv_neon.c index 6fd966d9..ddcdcc2d 100644 --- a/src/pulsecore/sconv_neon.c +++ b/src/pulsecore/sconv_neon.c @@ -36,18 +36,13 @@ static void pa_sconv_s16le_from_f32ne_neon(unsigned n, const float *src, int16_t "movs %[n], %[n], lsr #2 \n\t" "beq 2f \n\t" - "vdup.f32 q2, %[plusone] \n\t" - "vneg.f32 q3, q2 \n\t" - "vdup.f32 q4, %[scale] \n\t" - "vdup.u32 q5, %[mask] \n\t" + "vdup.f32 q1, %[scale] \n\t" "1: \n\t" "vld1.32 {q0}, [%[src]]! \n\t" - "vmin.f32 q0, q0, q2 \n\t" /* clamp */ - "vmax.f32 q0, q0, q3 \n\t" - "vmul.f32 q0, q0, q4 \n\t" /* scale */ - "vcvt.s32.f32 q0, q0, #16 \n\t" /* narrow */ - "vrshrn.s32 d0, q0, #16 \n\t" + "vmul.f32 q0, q0, q1 \n\t" /* scale */ + "vcvt.s32.f32 q0, q0, #16 \n\t" /* s32<-f32 as 16:16 fixed-point */ + "vqrshrn.s32 d0, q0, #16 \n\t" /* shift, round, narrow */ "subs %[n], %[n], #1 \n\t" "vst1.16 {d0}, [%[dst]]! \n\t" "bgt 1b \n\t" @@ -55,13 +50,13 @@ static void pa_sconv_s16le_from_f32ne_neon(unsigned n, const float *src, int16_t "2: \n\t" : [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), [mask] "r" (0x80000000) /* input operands */ - : "memory", "cc", "q0", "q1", "q2", "q3", "q4", "q5", "q6" /* clobber list */ + : [scale] "r" (32768.0f) /* input operands */ + : "memory", "cc", "q0", "q1" /* clobber list */ ); /* leftovers */ while (i--) { - *dst++ = (int16_t) lrintf(PA_CLAMP_UNLIKELY(*src, -1.0f, 1.0f) * 0x7FFF); + *dst++ = (int16_t) PA_CLAMP_UNLIKELY(lrintf(*src * (1 << 15)), -0x8000, 0x7FFF); src++; } } @@ -69,7 +64,7 @@ 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 / 0x7FFF; + const float invscale = 1.0f / (1 << 15); __asm__ __volatile__ ( "movs %[n], %[n], lsr #2 \n\t" @@ -79,8 +74,8 @@ static void pa_sconv_s16le_to_f32ne_neon(unsigned n, const int16_t *src, float * "1: \n\t" "vld1.16 {d0}, [%[src]]! \n\t" - "vmovl.s16 q0, d0 \n\t" - "vcvt.f32.s32 q0, q0 \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" "subs %[n], %[n], #1 \n\t" "vst1.32 {q0}, [%[dst]]! \n\t" diff --git a/src/pulsecore/sconv_sse.c b/src/pulsecore/sconv_sse.c index 34b59fa5..2f84f5ab 100644 --- a/src/pulsecore/sconv_sse.c +++ b/src/pulsecore/sconv_sse.c @@ -35,17 +35,13 @@ #if !defined(__APPLE__) && defined (__i386__) || defined (__amd64__) -static const PA_DECLARE_ALIGNED (16, float, one[4]) = { 1.0, 1.0, 1.0, 1.0 }; -static const PA_DECLARE_ALIGNED (16, float, mone[4]) = { -1.0, -1.0, -1.0, -1.0 }; -static const PA_DECLARE_ALIGNED (16, float, scale[4]) = { 0x7fff, 0x7fff, 0x7fff, 0x7fff }; +static const PA_DECLARE_ALIGNED (16, float, scale[4]) = { 0x8000, 0x8000, 0x8000, 0x8000 }; static void pa_sconv_s16le_from_f32ne_sse(unsigned n, const float *a, int16_t *b) { pa_reg_x86 temp, i; __asm__ __volatile__ ( " movaps %5, %%xmm5 \n\t" - " movaps %6, %%xmm6 \n\t" - " movaps %7, %%xmm7 \n\t" " xor %0, %0 \n\t" " mov %4, %1 \n\t" @@ -56,12 +52,8 @@ static void pa_sconv_s16le_from_f32ne_sse(unsigned n, const float *a, int16_t *b "1: \n\t" " movups (%q2, %0, 2), %%xmm0 \n\t" /* read 8 floats */ " movups 16(%q2, %0, 2), %%xmm2 \n\t" - " minps %%xmm5, %%xmm0 \n\t" /* clamp to 1.0 */ - " minps %%xmm5, %%xmm2 \n\t" - " maxps %%xmm6, %%xmm0 \n\t" /* clamp to -1.0 */ - " maxps %%xmm6, %%xmm2 \n\t" - " mulps %%xmm7, %%xmm0 \n\t" /* *= 0x7fff */ - " mulps %%xmm7, %%xmm2 \n\t" + " mulps %%xmm5, %%xmm0 \n\t" /* *= 0x8000 */ + " mulps %%xmm5, %%xmm2 \n\t" " cvtps2pi %%xmm0, %%mm0 \n\t" /* low part to int */ " cvtps2pi %%xmm2, %%mm2 \n\t" @@ -73,7 +65,7 @@ static void pa_sconv_s16le_from_f32ne_sse(unsigned n, const float *a, int16_t *b " packssdw %%mm1, %%mm0 \n\t" /* pack parts */ " packssdw %%mm3, %%mm2 \n\t" " movq %%mm0, (%q3, %0) \n\t" - " movq %%mm2, 8(%q3, %0) \n\t" + " movq %%mm2, 8(%q3, %0) \n\t" " add $16, %0 \n\t" " dec %1 \n\t" @@ -82,24 +74,30 @@ static void pa_sconv_s16le_from_f32ne_sse(unsigned n, const float *a, int16_t *b "2: \n\t" " mov %4, %1 \n\t" /* prepare for leftovers */ " and $7, %1 \n\t" - " je 4f \n\t" + " je 5f \n\t" "3: \n\t" " movss (%q2, %0, 2), %%xmm0 \n\t" - " minss %%xmm5, %%xmm0 \n\t" - " maxss %%xmm6, %%xmm0 \n\t" - " mulss %%xmm7, %%xmm0 \n\t" + " mulss %%xmm5, %%xmm0 \n\t" + " cvtss2si %%xmm0, %4 \n\t" + " add $0x8000, %4 \n\t" /* check for saturation */ + " and $~0xffff, %4 \n\t" " cvtss2si %%xmm0, %4 \n\t" - " movw %w4, (%q3, %0) \n\t" + " je 4f \n\t" + " sar $31, %4 \n\t" + " xor $0x7fff, %4 \n\t" + + "4: \n\t" + " movw %w4, (%q3, %0) \n\t" /* store leftover */ " add $2, %0 \n\t" " dec %1 \n\t" " jne 3b \n\t" - "4: \n\t" + "5: \n\t" " emms \n\t" : "=&r" (i), "=&r" (temp) - : "r" (a), "r" (b), "r" ((pa_reg_x86)n), "m" (*one), "m" (*mone), "m" (*scale) + : "r" (a), "r" (b), "r" ((pa_reg_x86)n), "m" (*scale) : "cc", "memory" ); } @@ -109,8 +107,6 @@ static void pa_sconv_s16le_from_f32ne_sse2(unsigned n, const float *a, int16_t * __asm__ __volatile__ ( " movaps %5, %%xmm5 \n\t" - " movaps %6, %%xmm6 \n\t" - " movaps %7, %%xmm7 \n\t" " xor %0, %0 \n\t" " mov %4, %1 \n\t" @@ -121,12 +117,8 @@ static void pa_sconv_s16le_from_f32ne_sse2(unsigned n, const float *a, int16_t * "1: \n\t" " movups (%q2, %0, 2), %%xmm0 \n\t" /* read 8 floats */ " movups 16(%q2, %0, 2), %%xmm2 \n\t" - " minps %%xmm5, %%xmm0 \n\t" /* clamp to 1.0 */ - " minps %%xmm5, %%xmm2 \n\t" - " maxps %%xmm6, %%xmm0 \n\t" /* clamp to -1.0 */ - " maxps %%xmm6, %%xmm2 \n\t" - " mulps %%xmm7, %%xmm0 \n\t" /* *= 0x7fff */ - " mulps %%xmm7, %%xmm2 \n\t" + " mulps %%xmm5, %%xmm0 \n\t" /* *= 0x8000 */ + " mulps %%xmm5, %%xmm2 \n\t" " cvtps2dq %%xmm0, %%xmm0 \n\t" " cvtps2dq %%xmm2, %%xmm2 \n\t" @@ -141,23 +133,29 @@ static void pa_sconv_s16le_from_f32ne_sse2(unsigned n, const float *a, int16_t * "2: \n\t" " mov %4, %1 \n\t" /* prepare for leftovers */ " and $7, %1 \n\t" - " je 4f \n\t" + " je 5f \n\t" "3: \n\t" " movss (%q2, %0, 2), %%xmm0 \n\t" - " minss %%xmm5, %%xmm0 \n\t" - " maxss %%xmm6, %%xmm0 \n\t" - " mulss %%xmm7, %%xmm0 \n\t" + " mulss %%xmm5, %%xmm0 \n\t" + " cvtss2si %%xmm0, %4 \n\t" + " add $0x8000, %4 \n\t" + " and $~0xffff, %4 \n\t" /* check for saturation */ " cvtss2si %%xmm0, %4 \n\t" - " movw %w4, (%q3, %0) \n\t" + " je 4f \n\t" + " sar $31, %4 \n\t" + " xor $0x7fff, %4 \n\t" + + "4: \n\t" + " movw %w4, (%q3, %0) \n\t" /* store leftover */ " add $2, %0 \n\t" " dec %1 \n\t" " jne 3b \n\t" - "4: \n\t" + "5: \n\t" : "=&r" (i), "=&r" (temp) - : "r" (a), "r" (b), "r" ((pa_reg_x86)n), "m" (*one), "m" (*mone), "m" (*scale) + : "r" (a), "r" (b), "r" ((pa_reg_x86)n), "m" (*scale) : "cc", "memory" ); } -- 2.39.2