ARM Skia NEON patches - 30 - Xfermode: NEON modeprocs

src/opts/SkColor_opts_neon.h

 #ifndef SkColor_opts_neon_DEFINED
 #define SkColor_opts_neon_DEFINED
 
 #include "SkTypes.h"
 
+#include <arm_neon.h>
+
 #define NEON_A (SK_A32_SHIFT / 8)
 #define NEON_R (SK_R32_SHIFT / 8)
 #define NEON_G (SK_G32_SHIFT / 8)
 #define NEON_B (SK_B32_SHIFT / 8)
 
+static inline uint16x8_t SkAlpha255To256_neon8(uint8x8_t alpha) {
+    return vaddw_u8(vdupq_n_u16(1), alpha);
+}
+
+static inline uint8x8_t SkAlphaMul_neon8(uint8x8_t color, uint16x8_t scale) {
+    return vshrn_n_u16(vmovl_u8(color) * scale, 8);
+}
+
+static inline uint8x8x4_t SkAlphaMulQ_neon8(uint8x8x4_t color, uint16x8_t scale) {
+    uint8x8x4_t ret;
+
+    ret.val[NEON_A] = SkAlphaMul_neon8(color.val[NEON_A], scale);
+    ret.val[NEON_R] = SkAlphaMul_neon8(color.val[NEON_R], scale);
+    ret.val[NEON_G] = SkAlphaMul_neon8(color.val[NEON_G], scale);
+    ret.val[NEON_B] = SkAlphaMul_neon8(color.val[NEON_B], scale);
+
+    return ret;
+}
+
 #endif /* #ifndef SkColor_opts_neon_DEFINED */