mmx: Use wpackhus in src_x888_0565 on iwMMXt

iwMMXt which has an unsigned saturation pack instruction, while MMX/EXT
and Loongson don't.

ARM/iwMMXt:
src_8888_0565 =  L1: 110.38  L2:  82.33  M: 40.92 ( 73.22%)  HT: 35.63  VT: 32.22  R: 30.07  RT: 18.40 ( 132Kops/s)
src_8888_0565 =  L1: 117.91  L2:  83.05  M: 41.52 ( 75.58%)  HT: 37.63  VT: 35.40  R: 29.37  RT: 19.39 ( 134Kops/s)

diff --git a/pixman/pixman-mmx.c b/pixman/pixman-mmx.c
index 7fe19d5..b14201a 100644 (file)
--- a/pixman/pixman-mmx.c
+++ b/pixman/pixman-mmx.c
@@ -589,9 +589,13 @@ pack_4xpacked565 (__m64 a, __m64 b)
     t1 = _mm_or_si64 (t1, g1);
 
     t0 = shift(t0, -5);
+#ifdef USE_ARM_IWMMXT
+    t1 = shift(t1, -5);
+    return _mm_packs_pu32 (t0, t1);
+#else
     t1 = shift(t1, -5 + 16);
-
     return _mm_shuffle_pi16 (_mm_or_si64 (t0, t1), _MM_SHUFFLE (3, 1, 2, 0));
+#endif
 }
 
 #ifndef _MSC_VER