> On Jun 20, 2024, at 20:49, Martin Storsjö <mar...@martin.st> wrote: > > On Thu, 20 Jun 2024, Zhao Zhili wrote: > >>> On Jun 19, 2024, at 20:05, Rémi Denis-Courmont <r...@remlab.net> wrote: >>> Le 19 juin 2024 11:24:28 GMT+02:00, Zhao Zhili <quinkbl...@foxmail.com >>> <mailto:quinkbl...@foxmail.com>> a écrit : >>>>> On Jun 19, 2024, at 15:07, Rémi Denis-Courmont <r...@remlab.net> wrote: >>>>> Le 15 juin 2024 11:57:18 GMT+02:00, Zhao Zhili <quinkbl...@foxmail.com> a >>>>> écrit : >>>>>> diff --git a/libswscale/aarch64/input.S b/libswscale/aarch64/input.S >>>>>> index 2b956fe5c2..37f1158504 100644 >>>>>> --- a/libswscale/aarch64/input.S >>>>>> +++ b/libswscale/aarch64/input.S >>>>>> @@ -20,8 +20,12 @@ >>>>>> #include "libavutil/aarch64/asm.S" >>>>>> -.macro rgb_to_yuv_load_rgb src >>>>>> +.macro rgb_to_yuv_load_rgb src, element=3 >>>>>> + .if \element == 3 >>>>>> ld3 { v16.16b, v17.16b, v18.16b }, [\src] >>>>>> + .else >>>>>> + ld4 { v16.16b, v17.16b, v18.16b, v19.16b }, [\src] >>>>>> + .endif >>>>>> uxtl v19.8h, v16.8b // v19: r >>>>>> uxtl v20.8h, v17.8b // v20: g >>>>>> uxtl v21.8h, v18.8b // v21: b >>>>>> @@ -43,7 +47,7 @@ >>>>>> sqshrn2 \dst\().8h, \dst2\().4s, \right_shift // >>>>>> dst_higher_half = dst2 >> right_shift >>>>>> .endm >>>>>> -.macro rgbToY bgr >>>>>> +.macro rgbToY bgr, element=3 >>>>> AFAICT, you don't need to a macro parameter for component order. Just >>>>> swap red and blue coefficients in the prologue and then run the bit-exact >>>>> same loops for bgr/rgb, rgba/bgra and argb/abgr. This adds one branch in >>>>> the prologue but that's mostly negligible compared to the loop. >>>> I’m not sure where to add the branch. Could you elaborate? Do you mean >>>> load coefficients first like the following: >>>> function ff_bgr24ToUV_half_neon, export=1 >>>> ldr w12, [x6, #12] >>>> ldr w11, [x6, #16] >>>> ldr w10, [x6, #20] >>>> ldr w15, [x6, #24] >>>> ldr w14, [x6, #28] >>>> ldr w13, [x6, #32] >>>> rgbToUV_half >>>> endfunc >>> Hmm, no. You need to jump past the loading of red and blue coefficients. It >>> might help to load green coefficients last. >>> By the way, I think you can use LDP instead of LDR. >> >> Patch v2 replace LDR by LDP, then the "jump past the loading of red and blue >> coefficients” doesn’t apply now. > > Rémi's point is that you don't need to duplicate the whole function, when the > only thing you're changing is a couple of instructions in the prologue of the > function. By reusing the actual bulk of the function, you save on binary size.
Thank you for the detailed examples. I missed the key point here is to save binary size. I have seen similar example of fall through in risk/input_rvv.s. Is it well defined to jump to a local label in another function? > > One way of doing it looks like this: > > diff --git a/libavutil/aarch64/asm.S b/libavutil/aarch64/asm.S > index 1840f9fb01..eb870e4dca 100644 > --- a/libavutil/aarch64/asm.S > +++ b/libavutil/aarch64/asm.S > @@ -256,5 +256,11 @@ ELF .size \name, . - \name > #define JOIN(a, b) GLUE(a, b) > #define X(s) JOIN(EXTERN_ASM, s) > > +#ifdef __APPLE__ > +#define L(x) L ## x > +#else > +#define L(x) .L ## x > +#endif > + > #define x18 do_not_use_x18 > #define w18 do_not_use_w18 > diff --git a/libswscale/aarch64/input.S b/libswscale/aarch64/input.S > index 33afa34111..ce10d584c6 100644 > --- a/libswscale/aarch64/input.S > +++ b/libswscale/aarch64/input.S > @@ -49,6 +49,7 @@ function ff_rgb24ToY_neon, export=1 > ldr w12, [x5, #8] // w12: by > b.le 3f > > +L(rgb24ToY_internal): > mov w9, #256 // w9 = 1 << (RGB2YUV_SHIFT - > 7) > movk w9, #8, lsl #16 // w9 += 32 << (RGB2YUV_SHIFT > - 1) > dup v6.4s, w9 // w9: const_offset > @@ -85,6 +86,14 @@ function ff_rgb24ToY_neon, export=1 > ret > endfunc > > +function ff_bgr24ToY_neon, export=1 > + cmp w4, #0 // check width > 0 > + ldp w12, w11, [x5] // w12: ry, w11: gy > + ldr w10, [x5, #8] // w10: by > + b.gt L(rgb24ToY_internal) > + ret > +endfunc > + > .macro rgb24_load_uv_coeff half > ldp w10, w11, [x6, #12] // w10: ru, w11: gu > ldp w12, w13, [x6, #20] // w12: bu, w13: rv > > > Another way looks like this: > > diff --git a/libswscale/aarch64/input.S b/libswscale/aarch64/input.S > index 33afa34111..5c4b7a41fd 100644 > --- a/libswscale/aarch64/input.S > +++ b/libswscale/aarch64/input.S > @@ -43,12 +43,23 @@ > sqshrn2 \dst\().8h, \dst2\().4s, \right_shift // > dst_higher_half = dst2 >> right_shift > .endm > > +function ff_bgr24ToY_neon, export=1 > + cmp w4, #0 // check width > 0 > + ldp w12, w11, [x5] // w12: ry, w11: gy > + ldr w10, [x5, #8] // w10: by > + b.gt rgb24ToY_internal > + ret > +endfunc > + > function ff_rgb24ToY_neon, export=1 > cmp w4, #0 // check width > 0 > ldp w10, w11, [x5] // w10: ry, w11: gy > ldr w12, [x5, #8] // w12: by > - b.le 3f > + b.gt rgb24ToY_internal > + ret > +endfunc > > +function rgb24ToY_internal > mov w9, #256 // w9 = 1 << (RGB2YUV_SHIFT - > 7) > movk w9, #8, lsl #16 // w9 += 32 << (RGB2YUV_SHIFT > - 1) > dup v6.4s, w9 // w9: const_offset > > > Or if you want to be really adventurous, you can make a fallthrough: > > > diff --git a/libswscale/aarch64/input.S b/libswscale/aarch64/input.S > index 33afa34111..025a965b76 100644 > --- a/libswscale/aarch64/input.S > +++ b/libswscale/aarch64/input.S > @@ -43,12 +43,22 @@ > sqshrn2 \dst\().8h, \dst2\().4s, \right_shift // > dst_higher_half = dst2 >> right_shift > .endm > > +function ff_bgr24ToY_neon, export=1 > + cmp w4, #0 // check width > 0 > + ldp w12, w11, [x5] // w12: ry, w11: gy > + ldr w10, [x5, #8] // w10: by > + b.gt rgb24ToY_internal > + ret > +endfunc > + > function ff_rgb24ToY_neon, export=1 > cmp w4, #0 // check width > 0 > ldp w10, w11, [x5] // w10: ry, w11: gy > ldr w12, [x5, #8] // w12: by > b.le 3f > +endfunc > > +function rgb24ToY_internal > mov w9, #256 // w9 = 1 << (RGB2YUV_SHIFT - > 7) > movk w9, #8, lsl #16 // w9 += 32 << (RGB2YUV_SHIFT > - 1) > dup v6.4s, w9 // w9: const_offset > > > // Martin > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
