[arm-simd] Add a comment about aligning source and destination pointers.

diff --git a/pixman/pixman-arm-simd.c b/pixman/pixman-arm-simd.c
index f595325..ceef1a8 100644 (file)
--- a/pixman/pixman-arm-simd.c
+++ b/pixman/pixman-arm-simd.c
@@ -60,6 +60,8 @@ fbCompositeSrcAdd_8000x8000arm (pixman_op_t op,
        srcLine += srcStride;
        w = width;
 
+        /* ensure both src and dst are properly aligned before doing 32 bit reads
+         * we'll stay in this loop if src and dst have differing alignments */
        while (w && (((unsigned long)dst & 3) || ((unsigned long)src & 3)))
        {
            s = *src;