[gtk/gtk-4-6] gdk: Remove pixel format conversion ARM intrinsics

[Matthias Clasen <matthiasc src gnome org>]

commit 08099ed17df19dd1ef8859ffa74d6ddc7fb84b40
Author: Emmanuel Gil Peyrot <linkmauve linkmauve fr>
Date:   Thu Mar 3 14:12:06 2022 +0000

    gdk: Remove pixel format conversion ARM intrinsics
    
    This was only useful when building for AArch32 without -mfpu=neon, on
    AArch64 or with -mfpu=neon gcc is smart enough to do the auto-
    vectorisation, leading to code almost as good as what I wrote in
    1fdf5b7cf8fec2d94389ecad5ec28865f8dcfd99.

 gdk/gdkmemoryformat.c | 50 --------------------------------------------------
 1 file changed, 50 deletions(-)
---
diff --git a/gdk/gdkmemoryformat.c b/gdk/gdkmemoryformat.c
index 64c027eac5..21667c1dcb 100644
--- a/gdk/gdkmemoryformat.c
+++ b/gdk/gdkmemoryformat.c
@@ -25,10 +25,6 @@
 
 #include <epoxy/gl.h>
 
-#ifdef __ARM_NEON
-#include <arm_neon.h>
-#endif
-
 typedef struct _GdkMemoryFormatDescription GdkMemoryFormatDescription;
 
 #define TYPED_FUNCS(name, T, R, G, B, A, bpp, scale) \
@@ -178,52 +174,6 @@ r8g8b8a8_to_b8g8r8a8_premultiplied (guchar *dest,
                                     const guchar *src,
                                     gsize n)
 {
-#ifdef __ARM_NEON
-  uint16x8_t one = vdupq_n_u16 (1);
-  uint16x8_t half = vdupq_n_u16 (127);
-
-  for (gsize i = n / 8; i > 0; i--)
-    {
-      // Work on “just” 8 pixels at once, since we need the full 16-bytes of
-      // the q registers for the multiplication.
-      uint8x8x4_t rgba = vld4_u8 (src);
-      uint8x8_t r8 = rgba.val[0];
-      uint8x8_t g8 = rgba.val[1];
-      uint8x8_t b8 = rgba.val[2];
-      uint8x8_t a8 = rgba.val[3];
-
-      // This is the same algorithm as premultiply(), but on packed 16-bit
-      // instead of float.
-      uint16x8_t r16 = vmull_u8 (r8, a8);
-      uint16x8_t g16 = vmull_u8 (g8, a8);
-      uint16x8_t b16 = vmull_u8 (b8, a8);
-
-      r16 = vaddq_u16 (r16, half);
-      g16 = vaddq_u16 (g16, half);
-      b16 = vaddq_u16 (b16, half);
-
-      r16 = vsraq_n_u16 (r16, r16, 8);
-      g16 = vsraq_n_u16 (g16, g16, 8);
-      b16 = vsraq_n_u16 (b16, b16, 8);
-
-      r16 = vaddq_u16 (r16, one);
-      g16 = vaddq_u16 (g16, one);
-      b16 = vaddq_u16 (b16, one);
-
-      // Just like the other one, here we use BGRA instead of RGBA!
-      rgba.val[0] = vshrn_n_u16 (b16, 8);
-      rgba.val[1] = vshrn_n_u16 (g16, 8);
-      rgba.val[2] = vshrn_n_u16 (r16, 8);
-
-      vst4_u8 (dest, rgba);
-      src += 32;
-      dest += 32;
-    }
-
-  // We want the fallthrough here for the last (up to) seven bytes of the row.
-  n = n % 8;
-#endif // __ARM_NEON
-
   for (; n > 0; n--)
     {
       guchar a = src[3];