swscale/ppc: VSX-optimize yuv2rgb_full

./ffmpeg -f lavfi -i yuvtestsrc=duration=1:size=1200x1440 \
        -s 1200x1440 -f null -vframes 100 -pix_fmt $i -nostats \
        -cpuflags 0 -v error -

This uses 32-bit mul, so POWER8 only.

The following output formats get about 4.5x speedup:

rgb24
  39980 UNITS in yuv2packed1,   32768 runs,      0 skips
   8774 UNITS in yuv2packed1,   32768 runs,      0 skips
bgr24
  40069 UNITS in yuv2packed1,   32768 runs,      0 skips
   8772 UNITS in yuv2packed1,   32766 runs,      2 skips
rgba
  39759 UNITS in yuv2packed1,   32768 runs,      0 skips
   8681 UNITS in yuv2packed1,   32767 runs,      1 skips
bgra
  39729 UNITS in yuv2packed1,   32768 runs,      0 skips
   8696 UNITS in yuv2packed1,   32766 runs,      2 skips
argb
  39766 UNITS in yuv2packed1,   32768 runs,      0 skips
   8672 UNITS in yuv2packed1,   32766 runs,      2 skips
bgra
  39784 UNITS in yuv2packed1,   32768 runs,      0 skips
   8659 UNITS in yuv2packed1,   32767 runs,      1 skips

1 files changed, 291 insertions, 0 deletions

diff --git a/libswscale/ppc/swscale_vsx.c b/libswscale/ppc/swscale_vsx.c
index 01eb46c..062ab0d 100644
--- a/libswscale/ppc/swscale_vsx.c
+++ b/libswscale/ppc/swscale_vsx.c
@@ -422,6 +422,248 @@ yuv2NBPSX(16, BE, 1, 16, int32_t)
 yuv2NBPSX(16, LE, 0, 16, int32_t)
 #endif
 
+static av_always_inline void
+yuv2rgb_full_1_vsx_template(SwsContext *c, const int16_t *buf0,
+                     const int16_t *ubuf[2], const int16_t *vbuf[2],
+                     const int16_t *abuf0, uint8_t *dest, int dstW,
+                     int uvalpha, int y, enum AVPixelFormat target,
+                     int hasAlpha)
+{
+    const int16_t *ubuf0 = ubuf[0], *vbuf0 = vbuf[0];
+    const int16_t *ubuf1 = ubuf[1], *vbuf1 = vbuf[1];
+    vector int16_t vy, vu, vv, A = vec_splat_s16(0), tmp16;
+    vector int32_t vy32_l, vy32_r, vu32_l, vu32_r, vv32_l, vv32_r, tmp32, tmp32_2;
+    vector int32_t R_l, R_r, G_l, G_r, B_l, B_r;
+    vector uint16_t rd16, gd16, bd16;
+    vector uint8_t rd, bd, gd, ad, out0, out1, tmp8;
+    const vector uint16_t zero16 = vec_splat_u16(0);
+    const vector int32_t y_offset = vec_splats(c->yuv2rgb_y_offset);
+    const vector int32_t y_coeff = vec_splats(c->yuv2rgb_y_coeff);
+    const vector int32_t y_add = vec_splats(1 << 21);
+    const vector int32_t v2r_coeff = vec_splats(c->yuv2rgb_v2r_coeff);
+    const vector int32_t v2g_coeff = vec_splats(c->yuv2rgb_v2g_coeff);
+    const vector int32_t u2g_coeff = vec_splats(c->yuv2rgb_u2g_coeff);
+    const vector int32_t u2b_coeff = vec_splats(c->yuv2rgb_u2b_coeff);
+    const vector int32_t rgbclip = vec_splats(1 << 30);
+    const vector int32_t zero32 = vec_splat_s32(0);
+    const vector uint32_t shift2 = vec_splat_u32(2);
+    const vector uint32_t shift22 = vec_splats(22U);
+    const vector uint16_t sub7 = vec_splats((uint16_t) (128 << 7));
+    const vector uint16_t sub8 = vec_splats((uint16_t) (128 << 8));
+    const vector int16_t mul4 = vec_splat_s16(4);
+    const vector int16_t mul8 = vec_splat_s16(8);
+    const vector int16_t add64 = vec_splat_s16(64);
+    const vector uint16_t shift7 = vec_splat_u16(7);
+    const vector int16_t max255 = vec_splat_s16(255);
+    int i;
+
+    // Various permutations
+    const vector uint8_t perm3rg0 = (vector uint8_t) {0x0, 0x10, 0,
+                                                      0x1, 0x11, 0,
+                                                      0x2, 0x12, 0,
+                                                      0x3, 0x13, 0,
+                                                      0x4, 0x14, 0,
+                                                      0x5 };
+    const vector uint8_t perm3rg1 = (vector uint8_t) {     0x15, 0,
+                                                      0x6, 0x16, 0,
+                                                      0x7, 0x17, 0 };
+    const vector uint8_t perm3tb0 = (vector uint8_t) {0x0, 0x1, 0x10,
+                                                      0x3, 0x4, 0x11,
+                                                      0x6, 0x7, 0x12,
+                                                      0x9, 0xa, 0x13,
+                                                      0xc, 0xd, 0x14,
+                                                      0xf };
+    const vector uint8_t perm3tb1 = (vector uint8_t) {     0x0, 0x15,
+                                                      0x2, 0x3, 0x16,
+                                                      0x5, 0x6, 0x17 };
+
+    for (i = 0; i < dstW; i += 8) { // The x86 asm also overwrites padding bytes.
+        vy = vec_ld(0, &buf0[i]);
+        vy32_l = vec_unpackh(vy);
+        vy32_r = vec_unpackl(vy);
+        vy32_l = vec_sl(vy32_l, shift2);
+        vy32_r = vec_sl(vy32_r, shift2);
+
+        vu = vec_ld(0, &ubuf0[i]);
+        vv = vec_ld(0, &vbuf0[i]);
+        if (uvalpha < 2048) {
+            vu = (vector int16_t) vec_sub((vector uint16_t) vu, sub7);
+            vv = (vector int16_t) vec_sub((vector uint16_t) vv, sub7);
+
+            tmp32 = vec_mule(vu, mul4);
+            tmp32_2 = vec_mulo(vu, mul4);
+            vu32_l = vec_mergeh(tmp32, tmp32_2);
+            vu32_r = vec_mergel(tmp32, tmp32_2);
+            tmp32 = vec_mule(vv, mul4);
+            tmp32_2 = vec_mulo(vv, mul4);
+            vv32_l = vec_mergeh(tmp32, tmp32_2);
+            vv32_r = vec_mergel(tmp32, tmp32_2);
+        } else {
+            tmp16 = vec_ld(0, &ubuf1[i]);
+            vu = vec_add(vu, tmp16);
+            vu = (vector int16_t) vec_sub((vector uint16_t) vu, sub8);
+            tmp16 = vec_ld(0, &vbuf1[i]);
+            vv = vec_add(vv, tmp16);
+            vv = (vector int16_t) vec_sub((vector uint16_t) vv, sub8);
+
+            vu32_l = vec_mule(vu, mul8);
+            vu32_r = vec_mulo(vu, mul8);
+            vv32_l = vec_mule(vv, mul8);
+            vv32_r = vec_mulo(vv, mul8);
+        }
+
+        if (hasAlpha) {
+            A = vec_ld(0, &abuf0[i]);
+            A = vec_add(A, add64);
+            A = vec_sr(A, shift7);
+            A = vec_max(A, max255);
+            ad = vec_packsu(A, (vector int16_t) zero16);
+        } else {
+            ad = vec_splats((uint8_t) 255);
+        }
+
+        vy32_l = vec_sub(vy32_l, y_offset);
+        vy32_r = vec_sub(vy32_r, y_offset);
+        vy32_l = vec_mul(vy32_l, y_coeff);
+        vy32_r = vec_mul(vy32_r, y_coeff);
+        vy32_l = vec_add(vy32_l, y_add);
+        vy32_r = vec_add(vy32_r, y_add);
+
+        R_l = vec_mul(vv32_l, v2r_coeff);
+        R_l = vec_add(R_l, vy32_l);
+        R_r = vec_mul(vv32_r, v2r_coeff);
+        R_r = vec_add(R_r, vy32_r);
+        G_l = vec_mul(vv32_l, v2g_coeff);
+        tmp32 = vec_mul(vu32_l, u2g_coeff);
+        G_l = vec_add(G_l, vy32_l);
+        G_l = vec_add(G_l, tmp32);
+        G_r = vec_mul(vv32_r, v2g_coeff);
+        tmp32 = vec_mul(vu32_r, u2g_coeff);
+        G_r = vec_add(G_r, vy32_r);
+        G_r = vec_add(G_r, tmp32);
+
+        B_l = vec_mul(vu32_l, u2b_coeff);
+        B_l = vec_add(B_l, vy32_l);
+        B_r = vec_mul(vu32_r, u2b_coeff);
+        B_r = vec_add(B_r, vy32_r);
+
+        R_l = vec_max(R_l, zero32);
+        R_r = vec_max(R_r, zero32);
+        G_l = vec_max(G_l, zero32);
+        G_r = vec_max(G_r, zero32);
+        B_l = vec_max(B_l, zero32);
+        B_r = vec_max(B_r, zero32);
+
+        R_l = vec_min(R_l, rgbclip);
+        R_r = vec_min(R_r, rgbclip);
+        G_l = vec_min(G_l, rgbclip);
+        G_r = vec_min(G_r, rgbclip);
+        B_l = vec_min(B_l, rgbclip);
+        B_r = vec_min(B_r, rgbclip);
+
+        R_l = vec_sr(R_l, shift22);
+        R_r = vec_sr(R_r, shift22);
+        G_l = vec_sr(G_l, shift22);
+        G_r = vec_sr(G_r, shift22);
+        B_l = vec_sr(B_l, shift22);
+        B_r = vec_sr(B_r, shift22);
+
+        rd16 = vec_packsu(R_l, R_r);
+        gd16 = vec_packsu(G_l, G_r);
+        bd16 = vec_packsu(B_l, B_r);
+        rd = vec_packsu(rd16, zero16);
+        gd = vec_packsu(gd16, zero16);
+        bd = vec_packsu(bd16, zero16);
+
+        switch(target) {
+        case AV_PIX_FMT_RGB24:
+            out0 = vec_perm(rd, gd, perm3rg0);
+            out0 = vec_perm(out0, bd, perm3tb0);
+            out1 = vec_perm(rd, gd, perm3rg1);
+            out1 = vec_perm(out1, bd, perm3tb1);
+
+            vec_vsx_st(out0, 0, dest);
+            vec_vsx_st(out1, 16, dest);
+
+            dest += 24;
+        break;
+        case AV_PIX_FMT_BGR24:
+            out0 = vec_perm(bd, gd, perm3rg0);
+            out0 = vec_perm(out0, rd, perm3tb0);
+            out1 = vec_perm(bd, gd, perm3rg1);
+            out1 = vec_perm(out1, rd, perm3tb1);
+
+            vec_vsx_st(out0, 0, dest);
+            vec_vsx_st(out1, 16, dest);
+
+            dest += 24;
+        break;
+        case AV_PIX_FMT_BGRA:
+            out0 = vec_mergeh(bd, gd);
+            out1 = vec_mergeh(rd, ad);
+
+            tmp8 = (vector uint8_t) vec_mergeh((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 0, dest);
+            tmp8 = (vector uint8_t) vec_mergel((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 16, dest);
+
+            dest += 32;
+        break;
+        case AV_PIX_FMT_RGBA:
+            out0 = vec_mergeh(rd, gd);
+            out1 = vec_mergeh(bd, ad);
+
+            tmp8 = (vector uint8_t) vec_mergeh((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 0, dest);
+            tmp8 = (vector uint8_t) vec_mergel((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 16, dest);
+
+            dest += 32;
+        break;
+        case AV_PIX_FMT_ARGB:
+            out0 = vec_mergeh(ad, rd);
+            out1 = vec_mergeh(gd, bd);
+
+            tmp8 = (vector uint8_t) vec_mergeh((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 0, dest);
+            tmp8 = (vector uint8_t) vec_mergel((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 16, dest);
+
+            dest += 32;
+        break;
+        case AV_PIX_FMT_ABGR:
+            out0 = vec_mergeh(ad, bd);
+            out1 = vec_mergeh(gd, rd);
+
+            tmp8 = (vector uint8_t) vec_mergeh((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 0, dest);
+            tmp8 = (vector uint8_t) vec_mergel((vector uint16_t) out0, (vector uint16_t) out1);
+            vec_vsx_st(tmp8, 16, dest);
+
+            dest += 32;
+        break;
+        }
+    }
+}
+
+#define YUV2RGBWRAPPER(name, base, ext, fmt, hasAlpha) \
+static void name ## ext ## _1_vsx(SwsContext *c, const int16_t *buf0, \
+                                const int16_t *ubuf[2], const int16_t *vbuf[2], \
+                                const int16_t *abuf0, uint8_t *dest, int dstW, \
+                                int uvalpha, int y) \
+{ \
+    name ## base ## _1_vsx_template(c, buf0, ubuf, vbuf, abuf0, dest, \
+                                  dstW, uvalpha, y, fmt, hasAlpha); \
+}
+
+YUV2RGBWRAPPER(yuv2, rgb_full, bgrx32_full, AV_PIX_FMT_BGRA,  0)
+YUV2RGBWRAPPER(yuv2, rgb_full, rgbx32_full, AV_PIX_FMT_RGBA,  0)
+YUV2RGBWRAPPER(yuv2, rgb_full, xrgb32_full, AV_PIX_FMT_ARGB,  0)
+YUV2RGBWRAPPER(yuv2, rgb_full, xbgr32_full, AV_PIX_FMT_ABGR,  0)
+
+YUV2RGBWRAPPER(yuv2, rgb_full, rgb24_full,  AV_PIX_FMT_RGB24, 0)
+YUV2RGBWRAPPER(yuv2, rgb_full, bgr24_full,  AV_PIX_FMT_BGR24, 0)
+
 #endif /* !HAVE_BIGENDIAN */
 
 #endif /* HAVE_VSX */
@@ -480,5 +722,54 @@ av_cold void ff_sws_init_swscale_vsx(SwsContext *c)
 #endif /* !HAVE_BIGENDIAN */
         }
     }
+
+    if (c->flags & SWS_BITEXACT)
+        return;
+
+#if !HAVE_BIGENDIAN
+    if (c->flags & SWS_FULL_CHR_H_INT) {
+        switch (dstFormat) {
+            case AV_PIX_FMT_RGB24:
+                if (HAVE_POWER8 && cpu_flags & AV_CPU_FLAG_POWER8) {
+                    c->yuv2packed1 = yuv2rgb24_full_1_vsx;
+                }
+            break;
+            case AV_PIX_FMT_BGR24:
+                if (HAVE_POWER8 && cpu_flags & AV_CPU_FLAG_POWER8) {
+                    c->yuv2packed1 = yuv2bgr24_full_1_vsx;
+                }
+            break;
+            case AV_PIX_FMT_BGRA:
+                if (HAVE_POWER8 && cpu_flags & AV_CPU_FLAG_POWER8) {
+                    if (!c->needAlpha) {
+                        c->yuv2packed1 = yuv2bgrx32_full_1_vsx;
+                    }
+                }
+            break;
+            case AV_PIX_FMT_RGBA:
+                if (HAVE_POWER8 && cpu_flags & AV_CPU_FLAG_POWER8) {
+                    if (!c->needAlpha) {
+                        c->yuv2packed1 = yuv2rgbx32_full_1_vsx;
+                    }
+                }
+            break;
+            case AV_PIX_FMT_ARGB:
+                if (HAVE_POWER8 && cpu_flags & AV_CPU_FLAG_POWER8) {
+                    if (!c->needAlpha) {
+                        c->yuv2packed1 = yuv2xrgb32_full_1_vsx;
+                    }
+                }
+            break;
+            case AV_PIX_FMT_ABGR:
+                if (HAVE_POWER8 && cpu_flags & AV_CPU_FLAG_POWER8) {
+                    if (!c->needAlpha) {
+                        c->yuv2packed1 = yuv2xbgr32_full_1_vsx;
+                    }
+                }
+            break;
+        }
+    }
+#endif /* !HAVE_BIGENDIAN */
+
 #endif /* HAVE_VSX */
 }