ARM Skia NEON patches - 30 - Xfermode: NEON modeprocs

src/opts/SkXfermode_opts_arm_neon.cpp

+#include "SkXfermode.h"
+#include "SkXfermode_proccoeff.h"
+#include "SkColorPriv.h"
+#include "SkUtilsArm.h"
+
+#include <arm_neon.h>
+#include "SkColor_opts_neon.h"
+
+#define SkAlphaMulAlpha(a, b)   SkMulDiv255Round(a, b)
+
+
+////////////////////////////////////////////////////////////////////////////////
+// NEONized skia functions
+////////////////////////////////////////////////////////////////////////////////
+
+static inline uint8x8_t SkAlphaMulAlpha_neon8(uint8x8_t color, uint8x8_t alpha) {
+    uint16x8_t tmp;
+    uint8x8_t ret;
+
+    tmp = vmull_u8(color, alpha);
+    tmp = vaddq_u16(tmp, vdupq_n_u16(128));
+    tmp = vaddq_u16(tmp, vshrq_n_u16(tmp, 8));
+
+    ret = vshrn_n_u16(tmp, 8);
+
+    return ret;
+}
+
+static inline uint16x8_t SkAlphaMulAlpha_neon8_16(uint8x8_t color, uint8x8_t alpha) {
+    uint16x8_t ret;
+
+    ret = vmull_u8(color, alpha);
+    ret = vaddq_u16(ret, vdupq_n_u16(128));
+    ret = vaddq_u16(ret, vshrq_n_u16(ret, 8));
+
+    ret = vshrq_n_u16(ret, 8);
+
+    return ret;
+}
+
+static inline uint8x8_t SkDiv255Round_neon8_32_8(int32x4_t p1, int32x4_t p2) {
+    uint16x8_t tmp;
+
+    tmp = vcombine_u16(vmovn_u32(vreinterpretq_u32_s32(p1)),
+                       vmovn_u32(vreinterpretq_u32_s32(p2)));
+
+    tmp += vdupq_n_u16(128);
+    tmp += vshrq_n_u16(tmp, 8);
+
+    return vshrn_n_u16(tmp, 8);
+}
+
+static inline uint16x8_t SkDiv255Round_neon8_16_16(uint16x8_t prod) {
+    prod += vdupq_n_u16(128);
+    prod += vshrq_n_u16(prod, 8);
+
+    return vshrq_n_u16(prod, 8);
+}
+
+static inline uint8x8_t clamp_div255round_simd8_32(int32x4_t val1, int32x4_t val2) {
+    uint8x8_t ret;
+    uint32x4_t cmp1, cmp2;
+    uint16x8_t cmp16;
+    uint8x8_t cmp8, cmp8_1;
+
+    // Test if <= 0
+    cmp1 = vcleq_s32(val1, vdupq_n_s32(0));
+    cmp2 = vcleq_s32(val2, vdupq_n_s32(0));
+    cmp16 = vcombine_u16(vmovn_u32(cmp1), vmovn_u32(cmp2));
+    cmp8_1 = vmovn_u16(cmp16);
+
+    // Init to zero
+    ret = vdup_n_u8(0);
+
+    // Test if >= 255*255
+    cmp1 = vcgeq_s32(val1, vdupq_n_s32(255*255));
+    cmp2 = vcgeq_s32(val2, vdupq_n_s32(255*255));
+    cmp16 = vcombine_u16(vmovn_u32(cmp1), vmovn_u32(cmp2));
+    cmp8 = vmovn_u16(cmp16);
+
+    // Insert 255 where true
+    ret = vbsl_u8(cmp8, vdup_n_u8(255), ret);
+
+    // Calc SkDiv255Round
+    uint8x8_t div = SkDiv255Round_neon8_32_8(val1, val2);
+
+    // Insert where false and previous test false
+    cmp8 = cmp8 | cmp8_1;
+    ret = vbsl_u8(cmp8, ret, div);
+
+    // Return the final combination
+    return ret;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// 8 pixels modeprocs
+////////////////////////////////////////////////////////////////////////////////
+
+uint8x8x4_t dstover_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint16x8_t src_scale;
+
+    src_scale = vsubw_u8(vdupq_n_u16(256), dst.val[NEON_A]);
+
+    ret.val[NEON_A] = dst.val[NEON_A] + SkAlphaMul_neon8(src.val[NEON_A], src_scale);
+    ret.val[NEON_R] = dst.val[NEON_R] + SkAlphaMul_neon8(src.val[NEON_R], src_scale);
+    ret.val[NEON_G] = dst.val[NEON_G] + SkAlphaMul_neon8(src.val[NEON_G], src_scale);
+    ret.val[NEON_B] = dst.val[NEON_B] + SkAlphaMul_neon8(src.val[NEON_B], src_scale);
+
+    return ret;
+}
+
+uint8x8x4_t srcin_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint16x8_t scale;
+
+    scale = SkAlpha255To256_neon8(dst.val[NEON_A]);
+
+    ret.val[NEON_A] = SkAlphaMul_neon8(src.val[NEON_A], scale);
+    ret.val[NEON_R] = SkAlphaMul_neon8(src.val[NEON_R], scale);
+    ret.val[NEON_G] = SkAlphaMul_neon8(src.val[NEON_G], scale);
+    ret.val[NEON_B] = SkAlphaMul_neon8(src.val[NEON_B], scale);
+
+    return ret;
+}
+
+uint8x8x4_t dstin_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint16x8_t scale;
+
+    scale = SkAlpha255To256_neon8(src.val[NEON_A]);
+
+    ret = SkAlphaMulQ_neon8(dst, scale);
+
+    return ret;
+}
+
+uint8x8x4_t srcout_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint16x8_t scale = vsubw_u8(vdupq_n_u16(256), dst.val[NEON_A]);
+
+    ret = SkAlphaMulQ_neon8(src, scale);
+
+    return ret;
+}
+
+uint8x8x4_t dstout_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint16x8_t scale = vsubw_u8(vdupq_n_u16(256), src.val[NEON_A]);
+
+    ret = SkAlphaMulQ_neon8(dst, scale);
+
+    return ret;
+}
+
+uint8x8x4_t srcatop_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint8x8_t isa;
+
+    isa = vsub_u8(vdup_n_u8(255), src.val[NEON_A]);
+
+    ret.val[NEON_A] = dst.val[NEON_A];
+    ret.val[NEON_R] = SkAlphaMulAlpha_neon8(src.val[NEON_R], dst.val[NEON_A])
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_R], isa);
+    ret.val[NEON_G] = SkAlphaMulAlpha_neon8(src.val[NEON_G], dst.val[NEON_A])
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_G], isa);
+    ret.val[NEON_B] = SkAlphaMulAlpha_neon8(src.val[NEON_B], dst.val[NEON_A])
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_B], isa);
+
+    return ret;
+}
+
+uint8x8x4_t dstatop_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint8x8_t ida;
+
+    ida = vsub_u8(vdup_n_u8(255), dst.val[NEON_A]);
+
+    ret.val[NEON_A] = src.val[NEON_A];
+    ret.val[NEON_R] = SkAlphaMulAlpha_neon8(src.val[NEON_R], ida)
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_R], src.val[NEON_A]);
+    ret.val[NEON_G] = SkAlphaMulAlpha_neon8(src.val[NEON_G], ida)
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_G], src.val[NEON_A]);
+    ret.val[NEON_B] = SkAlphaMulAlpha_neon8(src.val[NEON_B], ida)
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_B], src.val[NEON_A]);
+
+    return ret;
+}
+
+uint8x8x4_t xor_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+    uint8x8_t isa, ida;
+    uint16x8_t tmp_wide, tmp_wide2;
+
+    isa = vsub_u8(vdup_n_u8(255), src.val[NEON_A]);
+    ida = vsub_u8(vdup_n_u8(255), dst.val[NEON_A]);
+
+    // First calc alpha
+    tmp_wide = vmovl_u8(src.val[NEON_A]);
+    tmp_wide = vaddw_u8(tmp_wide, dst.val[NEON_A]);
+    tmp_wide2 = vshll_n_u8(SkAlphaMulAlpha_neon8(src.val[NEON_A], dst.val[NEON_A]), 1);
+    tmp_wide = vsubq_u16(tmp_wide, tmp_wide2);
+    ret.val[NEON_A] = vmovn_u16(tmp_wide);
+
+    // Then colors
+    ret.val[NEON_R] = SkAlphaMulAlpha_neon8(src.val[NEON_R], ida)
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_R], isa);
+    ret.val[NEON_G] = SkAlphaMulAlpha_neon8(src.val[NEON_G], ida)
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_G], isa);
+    ret.val[NEON_B] = SkAlphaMulAlpha_neon8(src.val[NEON_B], ida)
+                      + SkAlphaMulAlpha_neon8(dst.val[NEON_B], isa);
+
+    return ret;
+}
+
+uint8x8x4_t plus_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = vqadd_u8(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = vqadd_u8(src.val[NEON_R], dst.val[NEON_R]);
+    ret.val[NEON_G] = vqadd_u8(src.val[NEON_G], dst.val[NEON_G]);
+    ret.val[NEON_B] = vqadd_u8(src.val[NEON_B], dst.val[NEON_B]);
+
+    return ret;
+}
+
+uint8x8x4_t modulate_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = SkAlphaMulAlpha_neon8(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = SkAlphaMulAlpha_neon8(src.val[NEON_R], dst.val[NEON_R]);
+    ret.val[NEON_G] = SkAlphaMulAlpha_neon8(src.val[NEON_G], dst.val[NEON_G]);
+    ret.val[NEON_B] = SkAlphaMulAlpha_neon8(src.val[NEON_B], dst.val[NEON_B]);
+
+    return ret;
+}
+
+static inline uint8x8_t srcover_color(uint8x8_t a, uint8x8_t b) {
+    uint16x8_t tmp;
+
+    tmp = vaddl_u8(a, b);
+    tmp -= SkAlphaMulAlpha_neon8_16(a, b);
+
+    return vmovn_u16(tmp);
+}
+
+uint8x8x4_t screen_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = srcover_color(src.val[NEON_R], dst.val[NEON_R]);
+    ret.val[NEON_G] = srcover_color(src.val[NEON_G], dst.val[NEON_G]);
+    ret.val[NEON_B] = srcover_color(src.val[NEON_B], dst.val[NEON_B]);
+
+    return ret;
+}
+
+template <bool overlay>
+static inline uint8x8_t overlay_hardlight_color(uint8x8_t sc, uint8x8_t dc,
+                                               uint8x8_t sa, uint8x8_t da) {
+    /*
+     * In the end we're gonna use (rc + tmp) with a different rc
+     * coming from an alternative.
+     * The whole value (rc + tmp) can always be expressed as
+     * VAL = COM - SUB in the if case
+     * VAL = COM + SUB - sa*da in the else case
+     *
+     * with COM = 255 * (sc + dc)
+     * and  SUB = sc*da + dc*sa - 2*dc*sc
+     */
+
+    // Prepare common subexpressions
+    uint16x8_t const255 = vdupq_n_u16(255);
+    uint16x8_t sc_plus_dc = vaddl_u8(sc, dc);
+    uint16x8_t scda = vmull_u8(sc, da);
+    uint16x8_t dcsa = vmull_u8(dc, sa);
+    uint16x8_t sada = vmull_u8(sa, da);
+
+    // Prepare non common subexpressions
+    uint16x8_t dc2, sc2;
+    uint32x4_t scdc2_1, scdc2_2;
+    if (overlay) {
+        dc2 = vshll_n_u8(dc, 1);
+        scdc2_1 = vmull_u16(vget_low_u16(dc2), vget_low_u16(vmovl_u8(sc)));
+        scdc2_2 = vmull_u16(vget_high_u16(dc2), vget_high_u16(vmovl_u8(sc)));
+    } else {
+        sc2 = vshll_n_u8(sc, 1);
+        scdc2_1 = vmull_u16(vget_low_u16(sc2), vget_low_u16(vmovl_u8(dc)));
+        scdc2_2 = vmull_u16(vget_high_u16(sc2), vget_high_u16(vmovl_u8(dc)));
+    }
+
+    // Calc COM
+    int32x4_t com1, com2;
+    com1 = vreinterpretq_s32_u32(
+                vmull_u16(vget_low_u16(const255), vget_low_u16(sc_plus_dc)));
+    com2 = vreinterpretq_s32_u32(
+                vmull_u16(vget_high_u16(const255), vget_high_u16(sc_plus_dc)));
+
+    // Calc SUB
+    int32x4_t sub1, sub2;
+    sub1 = vreinterpretq_s32_u32(vaddl_u16(vget_low_u16(scda), vget_low_u16(dcsa)));
+    sub2 = vreinterpretq_s32_u32(vaddl_u16(vget_high_u16(scda), vget_high_u16(dcsa)));
+    sub1 = vsubq_s32(sub1, vreinterpretq_s32_u32(scdc2_1));
+    sub2 = vsubq_s32(sub2, vreinterpretq_s32_u32(scdc2_2));
+
+    // Compare 2*dc <= da
+    uint16x8_t cmp;
+
+    if (overlay) {
+        cmp = vcleq_u16(dc2, vmovl_u8(da));
+    } else {
+        cmp = vcleq_u16(sc2, vmovl_u8(sa));
+    }
+
+    // Prepare variables
+    int32x4_t val1_1, val1_2;
+    int32x4_t val2_1, val2_2;
+    uint32x4_t cmp1, cmp2;
+
+    cmp1 = vmovl_u16(vget_low_u16(cmp));
+    cmp1 |= vshlq_n_u32(cmp1, 16);
+    cmp2 = vmovl_u16(vget_high_u16(cmp));
+    cmp2 |= vshlq_n_u32(cmp2, 16);
+
+    // Calc COM - SUB
+    val1_1 = com1 - sub1;
+    val1_2 = com2 - sub2;
+
+    // Calc COM + SUB - sa*da
+    val2_1 = com1 + sub1;
+    val2_2 = com2 + sub2;
+
+    val2_1 = vsubq_s32(val2_1, vreinterpretq_s32_u32(vmovl_u16(vget_low_u16(sada))));
+    val2_2 = vsubq_s32(val2_2, vreinterpretq_s32_u32(vmovl_u16(vget_high_u16(sada))));
+
+    // Insert where needed
+    val1_1 = vbslq_s32(cmp1, val1_1, val2_1);
+    val1_2 = vbslq_s32(cmp2, val1_2, val2_2);
+
+    // Call the clamp_div255round function
+    return clamp_div255round_simd8_32(val1_1, val1_2);
+}
+
+static inline uint8x8_t overlay_color(uint8x8_t sc, uint8x8_t dc,
+                                      uint8x8_t sa, uint8x8_t da) {
+    return overlay_hardlight_color<true>(sc, dc, sa, da);
+}
+
+uint8x8x4_t overlay_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = overlay_color(src.val[NEON_R], dst.val[NEON_R],
+                                    src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = overlay_color(src.val[NEON_G], dst.val[NEON_G],
+                                    src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = overlay_color(src.val[NEON_B], dst.val[NEON_B],
+                                    src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+template <bool lighten>
+static inline uint8x8_t lighten_darken_color(uint8x8_t sc, uint8x8_t dc,
+                                             uint8x8_t sa, uint8x8_t da) {
+    uint16x8_t sd, ds, cmp, tmp, tmp2;
+
+    // Prepare
+    sd = vmull_u8(sc, da);
+    ds = vmull_u8(dc, sa);
+
+    // Do test
+    if (lighten) {
+        cmp = vcgtq_u16(sd, ds);
+    } else {
+        cmp = vcltq_u16(sd, ds);
+    }
+
+    // Assign if
+    tmp = vaddl_u8(sc, dc);
+    tmp2 = tmp;
+    tmp -= SkDiv255Round_neon8_16_16(ds);
+
+    // Calc else
+    tmp2 -= SkDiv255Round_neon8_16_16(sd);
+
+    // Insert where needed
+    tmp = vbslq_u16(cmp, tmp, tmp2);
+
+    return vmovn_u16(tmp);
+}
+
+static inline uint8x8_t darken_color(uint8x8_t sc, uint8x8_t dc,
+                                     uint8x8_t sa, uint8x8_t da) {
+    return lighten_darken_color<false>(sc, dc, sa, da);
+}
+
+uint8x8x4_t darken_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = darken_color(src.val[NEON_R], dst.val[NEON_R],
+                                   src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = darken_color(src.val[NEON_G], dst.val[NEON_G],
+                                   src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = darken_color(src.val[NEON_B], dst.val[NEON_B],
+                                   src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+static inline uint8x8_t lighten_color(uint8x8_t sc, uint8x8_t dc,
+                                      uint8x8_t sa, uint8x8_t da) {
+    return lighten_darken_color<true>(sc, dc, sa, da);
+}
+
+uint8x8x4_t lighten_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = lighten_color(src.val[NEON_R], dst.val[NEON_R],
+                                    src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = lighten_color(src.val[NEON_G], dst.val[NEON_G],
+                                    src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = lighten_color(src.val[NEON_B], dst.val[NEON_B],
+                                    src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+static inline uint8x8_t hardlight_color(uint8x8_t sc, uint8x8_t dc,
+                                        uint8x8_t sa, uint8x8_t da) {
+    return overlay_hardlight_color<false>(sc, dc, sa, da);
+}
+
+uint8x8x4_t hardlight_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = hardlight_color(src.val[NEON_R], dst.val[NEON_R],
+                                      src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = hardlight_color(src.val[NEON_G], dst.val[NEON_G],
+                                      src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = hardlight_color(src.val[NEON_B], dst.val[NEON_B],
+                                      src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+static inline uint8x8_t difference_color(uint8x8_t sc, uint8x8_t dc,
+                                         uint8x8_t sa, uint8x8_t da) {
+    uint16x8_t sd, ds, tmp;
+    int16x8_t val;
+
+    sd = vmull_u8(sc, da);
+    ds = vmull_u8(dc, sa);
+
+    tmp = vminq_u16(sd, ds);
+    tmp = SkDiv255Round_neon8_16_16(tmp);
+    tmp = vshlq_n_u16(tmp, 1);
+
+    val = vreinterpretq_s16_u16(vaddl_u8(sc, dc));
+
+    val -= vreinterpretq_s16_u16(tmp);
+
+    val = vmaxq_s16(val, vdupq_n_s16(0));
+    val = vminq_s16(val, vdupq_n_s16(255));
+
+    return vmovn_u16(vreinterpretq_u16_s16(val));
+}
+
+uint8x8x4_t difference_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = difference_color(src.val[NEON_R], dst.val[NEON_R],
+                                       src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = difference_color(src.val[NEON_G], dst.val[NEON_G],
+                                       src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = difference_color(src.val[NEON_B], dst.val[NEON_B],
+                                       src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+static inline uint8x8_t exclusion_color(uint8x8_t sc, uint8x8_t dc,
+                                        uint8x8_t sa, uint8x8_t da) {
+    /* The equation can be simplified to 255(sc + dc) - 2 * sc * dc */
+
+    uint16x8_t sc_plus_dc, scdc, const255;
+    int32x4_t term1_1, term1_2, term2_1, term2_2;
+
+    /* Calc (sc + dc) and (sc * dc) */
+    sc_plus_dc = vaddl_u8(sc, dc);
+    scdc = vmull_u8(sc, dc);
+
+    /* Prepare constants */
+    const255 = vdupq_n_u16(255);
+
+    /* Calc the first term */
+    term1_1 = vreinterpretq_s32_u32(
+                vmull_u16(vget_low_u16(const255), vget_low_u16(sc_plus_dc)));
+    term1_2 = vreinterpretq_s32_u32(
+                vmull_u16(vget_high_u16(const255), vget_high_u16(sc_plus_dc)));
+
+    /* Calc the second term */
+    term2_1 = vreinterpretq_s32_u32(vshll_n_u16(vget_low_u16(scdc), 1));
+    term2_2 = vreinterpretq_s32_u32(vshll_n_u16(vget_high_u16(scdc), 1));
+
+    return clamp_div255round_simd8_32(term1_1 - term2_1, term1_2 - term2_2);
+}
+
+uint8x8x4_t exclusion_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = exclusion_color(src.val[NEON_R], dst.val[NEON_R],
+                                      src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = exclusion_color(src.val[NEON_G], dst.val[NEON_G],
+                                      src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = exclusion_color(src.val[NEON_B], dst.val[NEON_B],
+                                      src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+static inline uint8x8_t blendfunc_multiply_color(uint8x8_t sc, uint8x8_t dc,
+                                                 uint8x8_t sa, uint8x8_t da) {
+    uint32x4_t val1, val2;
+    uint16x8_t scdc, t1, t2;
+
+    t1 = vmull_u8(sc, vdup_n_u8(255) - da);
+    t2 = vmull_u8(dc, vdup_n_u8(255) - sa);
+    scdc = vmull_u8(sc, dc);
+
+    val1 = vaddl_u16(vget_low_u16(t1), vget_low_u16(t2));
+    val2 = vaddl_u16(vget_high_u16(t1), vget_high_u16(t2));
+
+    val1 = vaddw_u16(val1, vget_low_u16(scdc));
+    val2 = vaddw_u16(val2, vget_high_u16(scdc));
+
+    return clamp_div255round_simd8_32(
+                vreinterpretq_s32_u32(val1), vreinterpretq_s32_u32(val2));
+}
+
+uint8x8x4_t multiply_modeproc_neon8(uint8x8x4_t src, uint8x8x4_t dst) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = srcover_color(src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_R] = blendfunc_multiply_color(src.val[NEON_R], dst.val[NEON_R],
+                                               src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_G] = blendfunc_multiply_color(src.val[NEON_G], dst.val[NEON_G],
+                                               src.val[NEON_A], dst.val[NEON_A]);
+    ret.val[NEON_B] = blendfunc_multiply_color(src.val[NEON_B], dst.val[NEON_B],
+                                               src.val[NEON_A], dst.val[NEON_A]);
+
+    return ret;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+typedef uint8x8x4_t (*SkXfermodeProcSIMD)(uint8x8x4_t src, uint8x8x4_t dst);
+
+class SkNEONProcCoeffXfermode : public SkProcCoeffXfermode {
+public:
+    SkNEONProcCoeffXfermode(const ProcCoeff& rec, SkXfermode::Mode mode,
+                            SkXfermodeProcSIMD procSIMD)
+            : INHERITED(rec, mode), fProcSIMD(procSIMD) {}
+
+    virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
+                        const SkAlpha aa[]) const SK_OVERRIDE;
+
+    SK_DEVELOPER_TO_STRING()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkNEONProcCoeffXfermode)
+
+private:
+    SkNEONProcCoeffXfermode(SkFlattenableReadBuffer& buffer)
+        : INHERITED(buffer) {
+
+        fProcSIMD = NULL;
+        if (!buffer.isCrossProcess()) {
+            fProcSIMD = (SkXfermodeProcSIMD)buffer.readFunctionPtr();
+        }
+    }
+
+    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE;
+
+    SkXfermodeProcSIMD fProcSIMD;
+    typedef SkProcCoeffXfermode INHERITED;
+};
+
+
+void SkNEONProcCoeffXfermode::xfer32(SkPMColor dst[], const SkPMColor src[],
+                                     int count, const SkAlpha aa[]) const {
+    SkASSERT(dst && src && count >= 0);
+
+    SkXfermodeProc proc = this->getProc();
+    SkXfermodeProcSIMD procSIMD = fProcSIMD;
+
+    if (NULL == aa) {
+        // Unrolled NEON code
+        while (count >= 8) {
+            uint8x8x4_t vsrc, vdst, vres;
+
+            asm volatile (
+                "vld4.u8    %h[vsrc], [%[src]]!  \t\n"
+                "vld4.u8    %h[vdst], [%[dst]]   \t\n"
+                : [vsrc] "=w" (vsrc), [vdst] "=w" (vdst)
+                : [src] "r" (src), [dst] "r" (dst)
+                :
+            );
+
+            vres = procSIMD(vsrc, vdst);
+
+            vst4_u8((uint8_t*)dst, vres);
+
+            count -= 8;
+            dst += 8;
+        }
+        // Leftovers
+        for (int i = 0; i < count; i++) {
+            dst[i] = proc(src[i], dst[i]);
+        }
+    } else {
+        for (int i = count - 1; i >= 0; --i) {
+            unsigned a = aa[i];
+            if (0 != a) {
+                SkPMColor dstC = dst[i];
+                SkPMColor C = proc(src[i], dstC);
+                if (a != 0xFF) {
+                    C = SkFourByteInterp(C, dstC, a);
+                }
+                dst[i] = C;
+            }
+        }
+    }
+}
+
+#ifdef SK_DEVELOPER
+void SkNEONProcCoeffXfermode::toString(SkString* str) const {
+    this->INHERITED::toString(str);
+}
+#endif
+
+void SkNEONProcCoeffXfermode::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
+    if (!buffer.isCrossProcess()) {
+        buffer.writeFunctionPtr((void*)fProcSIMD);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+SkXfermodeProcSIMD gNEONXfermodeProcs[] = {
+    [SkXfermode::kClear_Mode]   = NULL,
+    [SkXfermode::kSrc_Mode]     = NULL,
+    [SkXfermode::kDst_Mode]     = NULL,
+    [SkXfermode::kSrcOver_Mode] = NULL,
+    [SkXfermode::kDstOver_Mode] = dstover_modeproc_neon8,
+    [SkXfermode::kSrcIn_Mode]   = srcin_modeproc_neon8,
+    [SkXfermode::kDstIn_Mode]   = dstin_modeproc_neon8,
+    [SkXfermode::kSrcOut_Mode]  = srcout_modeproc_neon8,
+    [SkXfermode::kDstOut_Mode]  = dstout_modeproc_neon8,
+    [SkXfermode::kSrcATop_Mode] = srcatop_modeproc_neon8,
+    [SkXfermode::kDstATop_Mode] = dstatop_modeproc_neon8,
+    [SkXfermode::kXor_Mode]     = xor_modeproc_neon8,
+    [SkXfermode::kPlus_Mode]    = plus_modeproc_neon8,
+    [SkXfermode::kModulate_Mode]= modulate_modeproc_neon8,
+    [SkXfermode::kScreen_Mode]  = screen_modeproc_neon8,
+
+    [SkXfermode::kOverlay_Mode]    = overlay_modeproc_neon8,
+    [SkXfermode::kDarken_Mode]     = darken_modeproc_neon8,
+    [SkXfermode::kLighten_Mode]    = lighten_modeproc_neon8,
+    [SkXfermode::kColorDodge_Mode] = NULL,
+    [SkXfermode::kColorBurn_Mode]  = NULL,
+    [SkXfermode::kHardLight_Mode]  = hardlight_modeproc_neon8,
+    [SkXfermode::kSoftLight_Mode]  = NULL,
+    [SkXfermode::kDifference_Mode] = difference_modeproc_neon8,
+    [SkXfermode::kExclusion_Mode]  = exclusion_modeproc_neon8,
+    [SkXfermode::kMultiply_Mode]   = multiply_modeproc_neon8,
+
+    [SkXfermode::kHue_Mode]        = NULL,
+    [SkXfermode::kSaturation_Mode] = NULL,
+    [SkXfermode::kColor_Mode]      = NULL,
+    [SkXfermode::kLuminosity_Mode] = NULL,
+};
+
+SK_COMPILE_ASSERT(
+    SK_ARRAY_COUNT(gNEONXfermodeProcs) == SkXfermode::kLastMode + 1,
+    mode_count_arm
+);
+
+SkProcCoeffXfermode* SkPlatformXfermodeFactory(const ProcCoeff& rec,
+                                               SkXfermode::Mode mode) {
+#if SK_ARM_NEON_IS_DYNAMIC
+    if ((sk_cpu_arm_has_neon()) && (gNEONXfermodeProcs[mode] != NULL)) {

[djsollen, 2013/10/10 14:24:23]

my concern with putting this here is that this file is built with NEON. So there
is nothing from preventing the compiler from putting neon instructions in this
function.  However if NEON_IS_DYNAMIC and the device does not have neon then we
have problems.  I think the only way to get around this is to extern a function
from this file and use SK_ARM_NEON_WRAP in the opts_arm.cpp to select the right
function.

You can look at SkBlitRow_opts_* for reference.

+#elif SK_ARM_NEON_IS_ALWAYS
+    if (gNEONXfermodeProcs[mode] != NULL) {
+#endif
+        return SkNEW_ARGS(SkNEONProcCoeffXfermode,
+                          (rec, mode, gNEONXfermodeProcs[mode]));
+    }
+    return NULL;
+}