[FFmpeg-devel] [PATCHv2] lavu/x86/lls: add fma3 optimizations for update_lls
Ganesh Ajjanagadde
gajjanagadde at gmail.com
Thu Jan 14 23:46:43 CET 2016
This improves accuracy (very slightly) and speed for processors having
fma3.
Sample benchmark (fate flac-16-lpc-cholesky, Haswell):
old:
5993610 decicycles in ff_lpc_calc_coefs, 64 runs, 0 skips
5951528 decicycles in ff_lpc_calc_coefs, 128 runs, 0 skips
new:
5252410 decicycles in ff_lpc_calc_coefs, 64 runs, 0 skips
5232869 decicycles in ff_lpc_calc_coefs, 128 runs, 0 skips
Tested with FATE and --disable-fma3, also examined contents of
lavu/lls-test.
Reviewed-by: James Almer <jamrial at gmail.com>
Reviewed-by: Henrik Gramner <henrik at gramner.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
---
libavutil/x86/lls.asm | 61 ++++++++++++++++++++++++++++++++++++++++++++++--
libavutil/x86/lls_init.c | 4 ++++
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/libavutil/x86/lls.asm b/libavutil/x86/lls.asm
index 769befb..925cbdb 100644
--- a/libavutil/x86/lls.asm
+++ b/libavutil/x86/lls.asm
@@ -125,8 +125,7 @@ cglobal update_lls, 2,5,8, ctx, var, i, j, covar2
.ret:
REP_RET
-%if HAVE_AVX_EXTERNAL
-INIT_YMM avx
+%macro UPDATE_LLS 0
cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
%define covarq ctxq
mov countd, [ctxq + LLSModel.indep_count]
@@ -140,6 +139,18 @@ cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
vbroadcastsd ymm6, [varq + iq*8 + 16]
vbroadcastsd ymm7, [varq + iq*8 + 24]
vextractf128 xmm3, ymm1, 1
+%if cpuflag(fma3)
+ mova ymm0, COVAR(iq ,0)
+ mova xmm2, COVAR(iq+2,2)
+ fmaddpd ymm0, ymm1, ymm4, ymm0
+ fmaddpd xmm2, xmm3, xmm6, xmm2
+ fmaddpd ymm1, ymm5, ymm1, COVAR(iq ,1)
+ fmaddpd xmm3, xmm7, xmm3, COVAR(iq+2,3)
+ mova COVAR(iq ,0), ymm0
+ mova COVAR(iq ,1), ymm1
+ mova COVAR(iq+2,2), xmm2
+ mova COVAR(iq+2,3), xmm3
+%else
vmulpd ymm0, ymm1, ymm4
vmulpd ymm1, ymm1, ymm5
vmulpd xmm2, xmm3, xmm6
@@ -148,12 +159,27 @@ cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
ADDPD_MEM COVAR(iq ,1), ymm1
ADDPD_MEM COVAR(iq+2,2), xmm2
ADDPD_MEM COVAR(iq+2,3), xmm3
+%endif ; cpuflag(fma3)
lea jd, [iq + 4]
cmp jd, count2d
jg .skip4x4
.loop4x4:
; Compute all 16 pairwise products of a 4x4 block
mova ymm3, [varq + jq*8]
+%if cpuflag(fma3)
+ mova ymm0, COVAR(jq, 0)
+ mova ymm1, COVAR(jq, 1)
+ mova ymm2, COVAR(jq, 2)
+ mova ymm3, COVAR(jq, 3)
+ fmaddpd ymm0, ymm3, ymm4, ymm0
+ fmaddpd ymm1, ymm3, ymm5, ymm1
+ fmaddpd ymm2, ymm3, ymm6, ymm2
+ fmaddpd ymm3, ymm3, ymm7, ymm3
+ mova COVAR(jq, 0), ymm0
+ mova COVAR(jq, 1), ymm1
+ mova COVAR(jq, 2), ymm2
+ mova COVAR(jq, 3), ymm3
+%else
vmulpd ymm0, ymm3, ymm4
vmulpd ymm1, ymm3, ymm5
vmulpd ymm2, ymm3, ymm6
@@ -162,6 +188,7 @@ cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
ADDPD_MEM COVAR(jq,1), ymm1
ADDPD_MEM COVAR(jq,2), ymm2
ADDPD_MEM COVAR(jq,3), ymm3
+%endif ; cpuflag(fma3)
add jd, 4
cmp jd, count2d
jle .loop4x4
@@ -169,6 +196,20 @@ cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
cmp jd, countd
jg .skip2x4
mova xmm3, [varq + jq*8]
+%if cpuflag(fma3)
+ mova xmm0, COVAR(jq, 0)
+ mova xmm1, COVAR(jq, 1)
+ mova xmm2, COVAR(jq, 2)
+ mova xmm3, COVAR(jq, 3)
+ fmaddpd xmm0, xmm3, xmm4, xmm0
+ fmaddpd xmm1, xmm3, xmm5, xmm1
+ fmaddpd xmm2, xmm3, xmm6, xmm2
+ fmaddpd xmm3, xmm3, xmm7, xmm3
+ mova COVAR(jq, 0), xmm0
+ mova COVAR(jq, 1), xmm1
+ mova COVAR(jq, 2), xmm2
+ mova COVAR(jq, 3), xmm3
+%else
vmulpd xmm0, xmm3, xmm4
vmulpd xmm1, xmm3, xmm5
vmulpd xmm2, xmm3, xmm6
@@ -177,6 +218,7 @@ cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
ADDPD_MEM COVAR(jq,1), xmm1
ADDPD_MEM COVAR(jq,2), xmm2
ADDPD_MEM COVAR(jq,3), xmm3
+%endif ; cpuflag(fma3)
.skip2x4:
add id, 4
add covarq, 4*COVAR_STRIDE
@@ -187,14 +229,29 @@ cglobal update_lls, 3,6,8, ctx, var, count, i, j, count2
mov jd, id
.loop2x1:
vmovddup xmm0, [varq + iq*8]
+%if cpuflag(fma3)
+ mova xmm1, [varq + jq*8]
+ fmaddpd xmm0, xmm1, xmm0, COVAR(jq,0)
+ mova COVAR(jq,0), xmm0
+%else
vmulpd xmm0, [varq + jq*8]
ADDPD_MEM COVAR(jq,0), xmm0
+%endif ; cpuflag(fma3)
inc id
add covarq, COVAR_STRIDE
cmp id, countd
jle .loop2x1
.ret:
REP_RET
+%endmacro ; UPDATE_LLS
+
+%if HAVE_AVX_EXTERNAL
+INIT_YMM avx
+UPDATE_LLS
+%endif
+%if HAVE_FMA3_EXTERNAL
+INIT_YMM fma3
+UPDATE_LLS
%endif
INIT_XMM sse2
diff --git a/libavutil/x86/lls_init.c b/libavutil/x86/lls_init.c
index 81f141c..9f0d862 100644
--- a/libavutil/x86/lls_init.c
+++ b/libavutil/x86/lls_init.c
@@ -25,6 +25,7 @@
void ff_update_lls_sse2(LLSModel *m, const double *var);
void ff_update_lls_avx(LLSModel *m, const double *var);
+void ff_update_lls_fma3(LLSModel *m, const double *var);
double ff_evaluate_lls_sse2(LLSModel *m, const double *var, int order);
av_cold void ff_init_lls_x86(LLSModel *m)
@@ -38,4 +39,7 @@ av_cold void ff_init_lls_x86(LLSModel *m)
if (EXTERNAL_AVX_FAST(cpu_flags)) {
m->update_lls = ff_update_lls_avx;
}
+ if (EXTERNAL_FMA3(cpu_flags) && !(cpu_flags & AV_CPU_FLAG_AVXSLOW)) {
+ m->update_lls = ff_update_lls_fma3;
+ }
}
--
2.7.0
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