ARM: NEON optimised vector_fmul_reverse

Originally committed as revision 20029 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/arm/dsputil_neon.c

@@ -171,6 +171,8 @@ void ff_butterflies_float_neon(float *v1, float *v2, int len);
 float ff_scalarproduct_float_neon(const float *v1, const float *v2, int len);
 void ff_int32_to_float_fmul_scalar_neon(float *dst, const int *src,
                                         float mul, int len);
+void ff_vector_fmul_reverse_neon(float *dst, const float *src0,
+                                 const float *src1, int len);
 
 void ff_float_to_int16_neon(int16_t *, const float *, long);
 void ff_float_to_int16_interleave_neon(int16_t *, const float **, long, int);
@@ -287,6 +289,7 @@ void ff_dsputil_init_neon(DSPContext *c, AVCodecContext *avctx)
     c->butterflies_float = ff_butterflies_float_neon;
     c->scalarproduct_float = ff_scalarproduct_float_neon;
     c->int32_to_float_fmul_scalar = ff_int32_to_float_fmul_scalar_neon;
+    c->vector_fmul_reverse = ff_vector_fmul_reverse_neon;
 
     c->vector_fmul_sv_scalar[0] = ff_vector_fmul_sv_scalar_2_neon;
     c->vector_fmul_sv_scalar[1] = ff_vector_fmul_sv_scalar_4_neon;

libavcodec/arm/dsputil_neon_s.S

@@ -1051,3 +1051,27 @@ NOVFP   len     .req    r3
         bx              lr
         .unreq  len
         .endfunc
+
+function ff_vector_fmul_reverse_neon, export=1
+        add             r2,  r2,  r3,  lsl #2
+        sub             r2,  r2,  #32
+        mov             r12, #-32
+        vld1.32         {q0-q1},  [r1,:128]!
+        vld1.32         {q2-q3},  [r2,:128], r12
+1:      pld             [r1, #32]
+        vrev64.32       q3,  q3
+        vmul.f32        d16, d0,  d7
+        vmul.f32        d17, d1,  d6
+        pld             [r2, #-32]
+        vrev64.32       q2,  q2
+        vmul.f32        d18, d2,  d5
+        vmul.f32        d19, d3,  d4
+        subs            r3,  r3,  #8
+        beq             2f
+        vld1.32         {q0-q1},  [r1,:128]!
+        vld1.32         {q2-q3},  [r2,:128], r12
+        vst1.32         {q8-q9},  [r0,:128]!
+        b               1b
+2:      vst1.32         {q8-q9},  [r0,:128]!
+        bx              lr
+        .endfunc