mmx: optimize bilinear function when using 7-bit precision

Loongson:
image             firefox-fishtank 1037.738 1040.218   0.19%    3/3
image             firefox-fishtank 1056.611 1057.581   0.20%    3/3

ARM/iwMMXt:
image             firefox-fishtank 1487.282 1492.640   0.17%    3/3
image             firefox-fishtank 1363.913 1364.366   0.11%    3/3

diff --git a/pixman/pixman-mmx.c b/pixman/pixman-mmx.c
index 0c79f3a..5441d6b 100644 (file)
--- a/pixman/pixman-mmx.c
+++ b/pixman/pixman-mmx.c
@@ -3522,11 +3522,14 @@ mmx_composite_over_reverse_n_8888 (pixman_implementation_t *imp,
 }
 
 #define BSHIFT ((1 << BILINEAR_INTERPOLATION_BITS))
+#define BMSK (BSHIFT - 1)
 
 #define BILINEAR_DECLARE_VARIABLES                                             \
     const __m64 mm_wt = _mm_set_pi16 (wt, wt, wt, wt);                         \
     const __m64 mm_wb = _mm_set_pi16 (wb, wb, wb, wb);                         \
     const __m64 mm_BSHIFT = _mm_set_pi16 (BSHIFT, BSHIFT, BSHIFT, BSHIFT);     \
+    const __m64 mm_addc7 = _mm_set_pi16 (0, 1, 0, 1);                          \
+    const __m64 mm_xorc7 = _mm_set_pi16 (0, BMSK, 0, BMSK);                    \
     const __m64 mm_ux = _mm_set_pi16 (unit_x, unit_x, unit_x, unit_x);         \
     const __m64 mm_zero = _mm_setzero_si64 ();                                 \
     __m64 mm_x = _mm_set_pi16 (vx, vx, vx, vx)
@@ -3544,21 +3547,37 @@ do {                                                                            \
     __m64 b_lo = _mm_mullo_pi16 (_mm_unpacklo_pi8 (b, mm_zero), mm_wb);                \
     __m64 hi = _mm_add_pi16 (t_hi, b_hi);                                      \
     __m64 lo = _mm_add_pi16 (t_lo, b_lo);                                      \
-    /* calculate horizontal weights */                                         \
-    __m64 mm_wh_lo = _mm_sub_pi16 (mm_BSHIFT, _mm_srli_pi16 (mm_x,             \
+    if (BILINEAR_INTERPOLATION_BITS < 8)                                       \
+    {                                                                          \
+       /* calculate horizontal weights */                                      \
+       __m64 mm_wh = _mm_add_pi16 (mm_addc7, _mm_xor_si64 (mm_xorc7,           \
+                         _mm_srli_pi16 (mm_x,                                  \
+                                        16 - BILINEAR_INTERPOLATION_BITS)));   \
+       mm_x = _mm_add_pi16 (mm_x, mm_ux);                                      \
+       /* horizontal interpolation */                                          \
+       __m64 p = _mm_unpacklo_pi16 (lo, hi);                                   \
+       __m64 q = _mm_unpackhi_pi16 (lo, hi);                                   \
+       lo = _mm_madd_pi16 (p, mm_wh);                                          \
+       hi = _mm_madd_pi16 (q, mm_wh);                                          \
+    }                                                                          \
+    else                                                                       \
+    {                                                                          \
+       /* calculate horizontal weights */                                      \
+       __m64 mm_wh_lo = _mm_sub_pi16 (mm_BSHIFT, _mm_srli_pi16 (mm_x,          \
                                        16 - BILINEAR_INTERPOLATION_BITS));     \
-    __m64 mm_wh_hi = _mm_srli_pi16 (mm_x,                                      \
+       __m64 mm_wh_hi = _mm_srli_pi16 (mm_x,                                   \
                                        16 - BILINEAR_INTERPOLATION_BITS);      \
-    mm_x = _mm_add_pi16 (mm_x, mm_ux);                                         \
-    /* horizontal interpolation */                                             \
-    __m64 mm_lo_lo = _mm_mullo_pi16 (lo, mm_wh_lo);                            \
-    __m64 mm_lo_hi = _mm_mullo_pi16 (hi, mm_wh_hi);                            \
-    __m64 mm_hi_lo = _mm_mulhi_pu16 (lo, mm_wh_lo);                            \
-    __m64 mm_hi_hi = _mm_mulhi_pu16 (hi, mm_wh_hi);                            \
-    lo = _mm_add_pi32 (_mm_unpacklo_pi16 (mm_lo_lo, mm_hi_lo),                 \
-                      _mm_unpacklo_pi16 (mm_lo_hi, mm_hi_hi));                 \
-    hi = _mm_add_pi32 (_mm_unpackhi_pi16 (mm_lo_lo, mm_hi_lo),                 \
-                      _mm_unpackhi_pi16 (mm_lo_hi, mm_hi_hi));                 \
+       mm_x = _mm_add_pi16 (mm_x, mm_ux);                                      \
+       /* horizontal interpolation */                                          \
+       __m64 mm_lo_lo = _mm_mullo_pi16 (lo, mm_wh_lo);                         \
+       __m64 mm_lo_hi = _mm_mullo_pi16 (hi, mm_wh_hi);                         \
+       __m64 mm_hi_lo = _mm_mulhi_pu16 (lo, mm_wh_lo);                         \
+       __m64 mm_hi_hi = _mm_mulhi_pu16 (hi, mm_wh_hi);                         \
+       lo = _mm_add_pi32 (_mm_unpacklo_pi16 (mm_lo_lo, mm_hi_lo),              \
+                          _mm_unpacklo_pi16 (mm_lo_hi, mm_hi_hi));             \
+       hi = _mm_add_pi32 (_mm_unpackhi_pi16 (mm_lo_lo, mm_hi_lo),              \
+                          _mm_unpackhi_pi16 (mm_lo_hi, mm_hi_hi));             \
+    }                                                                          \
     /* shift and pack the result */                                            \
     hi = _mm_srli_pi32 (hi, BILINEAR_INTERPOLATION_BITS * 2);                  \
     lo = _mm_srli_pi32 (lo, BILINEAR_INTERPOLATION_BITS * 2);                  \