[FFmpeg-cvslog] arm: Add VFP-accelerated version of int32_to_float_fmul_array8
Ben Avison
git at videolan.org
Mon Jul 22 12:04:30 CEST 2013
ffmpeg | branch: master | Ben Avison <bavison at riscosopen.org> | Mon Jul 15 18:28:12 2013 +0100| [d6e4f5fef0d811e180fd7541941e07dca9e11dc0] | committer: Martin Storsjö
arm: Add VFP-accelerated version of int32_to_float_fmul_array8
Before After
Mean StdDev Mean StdDev Change
This function 366.2 18.3 277.8 13.7 +31.9%
Overall 18420.5 489.1 17049.5 408.2 +8.0%
Signed-off-by: Martin Storsjö <martin at martin.st>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d6e4f5fef0d811e180fd7541941e07dca9e11dc0
---
libavcodec/arm/fmtconvert_init_arm.c | 6 +-
libavcodec/arm/fmtconvert_vfp.S | 162 ++++++++++++++++++++++++++++++++++
2 files changed, 167 insertions(+), 1 deletion(-)
diff --git a/libavcodec/arm/fmtconvert_init_arm.c b/libavcodec/arm/fmtconvert_init_arm.c
index 9aab7bb..eb66eb8 100644
--- a/libavcodec/arm/fmtconvert_init_arm.c
+++ b/libavcodec/arm/fmtconvert_init_arm.c
@@ -30,6 +30,9 @@ void ff_int32_to_float_fmul_scalar_neon(float *dst, const int32_t *src,
void ff_int32_to_float_fmul_scalar_vfp(float *dst, const int32_t *src,
float mul, int len);
+void ff_int32_to_float_fmul_array8_vfp(FmtConvertContext *c, float *dst,
+ const int32_t *src, const float *mul,
+ int len);
void ff_float_to_int16_neon(int16_t *dst, const float *src, long len);
void ff_float_to_int16_interleave_neon(int16_t *, const float **, long, int);
@@ -42,10 +45,11 @@ av_cold void ff_fmt_convert_init_arm(FmtConvertContext *c, AVCodecContext *avctx
if (have_vfp(cpu_flags) && have_armv6(cpu_flags)) {
if (!have_vfpv3(cpu_flags)) {
- // This function doesn't use anything armv6 specific in itself,
+ // These functions don't use anything armv6 specific in themselves,
// but ff_float_to_int16_vfp which is in the same assembly source
// file does, thus the whole file requires armv6 to be built.
c->int32_to_float_fmul_scalar = ff_int32_to_float_fmul_scalar_vfp;
+ c->int32_to_float_fmul_array8 = ff_int32_to_float_fmul_array8_vfp;
}
c->float_to_int16 = ff_float_to_int16_vfp;
diff --git a/libavcodec/arm/fmtconvert_vfp.S b/libavcodec/arm/fmtconvert_vfp.S
index 349c198..d841802 100644
--- a/libavcodec/arm/fmtconvert_vfp.S
+++ b/libavcodec/arm/fmtconvert_vfp.S
@@ -83,6 +83,168 @@ endfunc
* Assume len is a multiple of 8, destination buffer is at least 4 bytes aligned
* (16 bytes alignment is best for BCM2835), little-endian.
*/
+@ void ff_int32_to_float_fmul_array8_vfp(FmtConvertContext *c, float *dst, const int32_t *src, const float *mul, int len)
+function ff_int32_to_float_fmul_array8_vfp, export=1
+ push {lr}
+ ldr a1, [sp, #4]
+ subs lr, a1, #3*8
+ bcc 50f @ too short to pipeline
+ @ Now need to find (len / 8) % 3. The approximation
+ @ x / 24 = (x * 0xAB) >> 12
+ @ is good for x < 4096, which is true for both AC3 and DCA.
+ mov a1, #0xAB
+ ldr ip, =0x03070000 @ RunFast mode, short vectors of length 8, stride 1
+ mul a1, lr, a1
+ vpush {s16-s31}
+ mov a1, a1, lsr #12
+ add a1, a1, a1, lsl #1
+ rsb a1, a1, lr, lsr #3
+ cmp a1, #1
+ fmrx a1, FPSCR
+ fmxr FPSCR, ip
+ beq 11f
+ blo 10f
+ @ Array is (2 + multiple of 3) x 8 floats long
+ @ drop through...
+ vldmia a3!, {s16-s23}
+ vldmia a4!, {s2,s3}
+ vldmia a3!, {s24-s31}
+ vcvt.f32.s32 s16, s16
+ vcvt.f32.s32 s17, s17
+ vcvt.f32.s32 s18, s18
+ vcvt.f32.s32 s19, s19
+ vcvt.f32.s32 s20, s20
+ vcvt.f32.s32 s21, s21
+ vcvt.f32.s32 s22, s22
+ vcvt.f32.s32 s23, s23
+ vmul.f32 s16, s16, s2
+ @ drop through...
+3:
+ vldmia a3!, {s8-s15}
+ vldmia a4!, {s1}
+ vcvt.f32.s32 s24, s24
+ vcvt.f32.s32 s25, s25
+ vcvt.f32.s32 s26, s26
+ vcvt.f32.s32 s27, s27
+ vcvt.f32.s32 s28, s28
+ vcvt.f32.s32 s29, s29
+ vcvt.f32.s32 s30, s30
+ vcvt.f32.s32 s31, s31
+ vmul.f32 s24, s24, s3
+ vstmia a2!, {s16-s19}
+ vstmia a2!, {s20-s23}
+2:
+ vldmia a3!, {s16-s23}
+ vldmia a4!, {s2}
+ vcvt.f32.s32 s8, s8
+ vcvt.f32.s32 s9, s9
+ vcvt.f32.s32 s10, s10
+ vcvt.f32.s32 s11, s11
+ vcvt.f32.s32 s12, s12
+ vcvt.f32.s32 s13, s13
+ vcvt.f32.s32 s14, s14
+ vcvt.f32.s32 s15, s15
+ vmul.f32 s8, s8, s1
+ vstmia a2!, {s24-s27}
+ vstmia a2!, {s28-s31}
+1:
+ vldmia a3!, {s24-s31}
+ vldmia a4!, {s3}
+ vcvt.f32.s32 s16, s16
+ vcvt.f32.s32 s17, s17
+ vcvt.f32.s32 s18, s18
+ vcvt.f32.s32 s19, s19
+ vcvt.f32.s32 s20, s20
+ vcvt.f32.s32 s21, s21
+ vcvt.f32.s32 s22, s22
+ vcvt.f32.s32 s23, s23
+ vmul.f32 s16, s16, s2
+ vstmia a2!, {s8-s11}
+ vstmia a2!, {s12-s15}
+
+ subs lr, lr, #8*3
+ bpl 3b
+
+ vcvt.f32.s32 s24, s24
+ vcvt.f32.s32 s25, s25
+ vcvt.f32.s32 s26, s26
+ vcvt.f32.s32 s27, s27
+ vcvt.f32.s32 s28, s28
+ vcvt.f32.s32 s29, s29
+ vcvt.f32.s32 s30, s30
+ vcvt.f32.s32 s31, s31
+ vmul.f32 s24, s24, s3
+ vstmia a2!, {s16-s19}
+ vstmia a2!, {s20-s23}
+ vstmia a2!, {s24-s27}
+ vstmia a2!, {s28-s31}
+
+ fmxr FPSCR, a1
+ vpop {s16-s31}
+ pop {pc}
+
+10: @ Array is (multiple of 3) x 8 floats long
+ vldmia a3!, {s8-s15}
+ vldmia a4!, {s1,s2}
+ vldmia a3!, {s16-s23}
+ vcvt.f32.s32 s8, s8
+ vcvt.f32.s32 s9, s9
+ vcvt.f32.s32 s10, s10
+ vcvt.f32.s32 s11, s11
+ vcvt.f32.s32 s12, s12
+ vcvt.f32.s32 s13, s13
+ vcvt.f32.s32 s14, s14
+ vcvt.f32.s32 s15, s15
+ vmul.f32 s8, s8, s1
+ b 1b
+
+11: @ Array is (1 + multiple of 3) x 8 floats long
+ vldmia a3!, {s24-s31}
+ vldmia a4!, {s3}
+ vldmia a3!, {s8-s15}
+ vldmia a4!, {s1}
+ vcvt.f32.s32 s24, s24
+ vcvt.f32.s32 s25, s25
+ vcvt.f32.s32 s26, s26
+ vcvt.f32.s32 s27, s27
+ vcvt.f32.s32 s28, s28
+ vcvt.f32.s32 s29, s29
+ vcvt.f32.s32 s30, s30
+ vcvt.f32.s32 s31, s31
+ vmul.f32 s24, s24, s3
+ b 2b
+
+50:
+ ldr lr, =0x03070000 @ RunFast mode, short vectors of length 8, stride 1
+ fmrx ip, FPSCR
+ fmxr FPSCR, lr
+51:
+ vldmia a3!, {s8-s15}
+ vldmia a4!, {s0}
+ vcvt.f32.s32 s8, s8
+ vcvt.f32.s32 s9, s9
+ vcvt.f32.s32 s10, s10
+ vcvt.f32.s32 s11, s11
+ vcvt.f32.s32 s12, s12
+ vcvt.f32.s32 s13, s13
+ vcvt.f32.s32 s14, s14
+ vcvt.f32.s32 s15, s15
+ vmul.f32 s8, s8, s0
+ subs a1, a1, #8
+ vstmia a2!, {s8-s11}
+ vstmia a2!, {s12-s15}
+ bne 51b
+
+ fmxr FPSCR, ip
+ pop {pc}
+endfunc
+
+/**
+ * ARM VFP optimised int32 to float conversion.
+ * Assume len is a multiple of 8, destination buffer is at least 4 bytes aligned
+ * (16 bytes alignment is best for BCM2835), little-endian.
+ * TODO: could be further optimised by unrolling and interleaving, as above
+ */
@ void ff_int32_to_float_fmul_scalar_vfp(float *dst, const int32_t *src, float mul, int len)
function ff_int32_to_float_fmul_scalar_vfp, export=1
VFP tmp .req a4
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