mmx: don't pack and unpack src unnecessarily

The combine function was store8888'ing the result, and all consumers
were immediately load8888'ing it, causing lots of unnecessary pack and
unpack instructions.

It's a very straight forward conversion, except for mmx_combine_over_u
and mmx_combine_saturate_u. mmx_combine_over_u was testing the integer
result to skip pixels, so we use the is_* functions to test the __m64
data directly without loading it into an integer register.

For mmx_combine_saturate_u there's not a lot we can do, since it uses
DIV_UN8.

diff --git a/pixman/pixman-mmx.c b/pixman/pixman-mmx.c
index 1290fc4..f40fa71 100644 (file)
--- a/pixman/pixman-mmx.c
+++ b/pixman/pixman-mmx.c
@@ -569,23 +569,20 @@ pix_add_mul (__m64 x, __m64 a, __m64 y, __m64 b)
 
 /* --------------- MMX code patch for fbcompose.c --------------------- */
 
-static force_inline uint32_t
+static force_inline __m64
 combine (const uint32_t *src, const uint32_t *mask)
 {
-    uint32_t ssrc = *src;
+    __m64 vsrc = load8888 (src);
 
     if (mask)
     {
        __m64 m = load8888 (mask);
-       __m64 s = load8888 (&ssrc);
 
        m = expand_alpha (m);
-       s = pix_multiply (s, m);
-
-       store8888 (&ssrc, s);
+       vsrc = pix_multiply (vsrc, m);
     }
 
-    return ssrc;
+    return vsrc;
 }
 
 static void
@@ -600,19 +597,16 @@ mmx_combine_over_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       uint32_t ssrc = combine (src, mask);
-       uint32_t a = ssrc >> 24;
+       __m64 vsrc = combine (src, mask);
 
-       if (a == 0xff)
+       if (is_opaque (vsrc))
        {
-           *dest = ssrc;
+           store8888 (dest, vsrc);
        }
-       else if (ssrc)
+       else if (!is_zero (vsrc))
        {
-           __m64 s, sa;
-           s = load8888 (&ssrc);
-           sa = expand_alpha (s);
-           store8888 (dest, over (s, sa, load8888 (dest)));
+           __m64 sa = expand_alpha (vsrc);
+           store8888 (dest, over (vsrc, sa, load8888 (dest)));
        }
 
        ++dest;
@@ -636,11 +630,11 @@ mmx_combine_over_reverse_u (pixman_implementation_t *imp,
     while (dest < end)
     {
        __m64 d, da;
-       uint32_t s = combine (src, mask);
+       __m64 s = combine (src, mask);
 
        d = load8888 (dest);
        da = expand_alpha (d);
-       store8888 (dest, over (d, da, load8888 (&s)));
+       store8888 (dest, over (d, da, s));
 
        ++dest;
        ++src;
@@ -662,10 +656,9 @@ mmx_combine_in_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 x, a;
-       uint32_t ssrc = combine (src, mask);
+       __m64 a;
+       __m64 x = combine (src, mask);
 
-       x = load8888 (&ssrc);
        a = load8888 (dest);
        a = expand_alpha (a);
        x = pix_multiply (x, a);
@@ -692,11 +685,10 @@ mmx_combine_in_reverse_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 x, a;
-       uint32_t ssrc = combine (src, mask);
+       __m64 a = combine (src, mask);
+       __m64 x;
 
        x = load8888 (dest);
-       a = load8888 (&ssrc);
        a = expand_alpha (a);
        x = pix_multiply (x, a);
        store8888 (dest, x);
@@ -721,10 +713,9 @@ mmx_combine_out_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 x, a;
-       uint32_t ssrc = combine (src, mask);
+       __m64 a;
+       __m64 x = combine (src, mask);
 
-       x = load8888 (&ssrc);
        a = load8888 (dest);
        a = expand_alpha (a);
        a = negate (a);
@@ -751,11 +742,10 @@ mmx_combine_out_reverse_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 x, a;
-       uint32_t ssrc = combine (src, mask);
+       __m64 a = combine (src, mask);
+       __m64 x;
 
        x = load8888 (dest);
-       a = load8888 (&ssrc);
        a = expand_alpha (a);
        a = negate (a);
        x = pix_multiply (x, a);
@@ -782,10 +772,9 @@ mmx_combine_atop_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 s, da, d, sia;
-       uint32_t ssrc = combine (src, mask);
+       __m64 da, d, sia;
+       __m64 s = combine (src, mask);
 
-       s = load8888 (&ssrc);
        d = load8888 (dest);
        sia = expand_alpha (s);
        sia = negate (sia);
@@ -815,10 +804,9 @@ mmx_combine_atop_reverse_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 s, dia, d, sa;
-       uint32_t ssrc = combine (src, mask);
+       __m64 dia, d, sa;
+       __m64 s = combine (src, mask);
 
-       s = load8888 (&ssrc);
        d = load8888 (dest);
        sa = expand_alpha (s);
        dia = expand_alpha (d);
@@ -846,10 +834,9 @@ mmx_combine_xor_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 s, dia, d, sia;
-       uint32_t ssrc = combine (src, mask);
+       __m64 dia, d, sia;
+       __m64 s = combine (src, mask);
 
-       s = load8888 (&ssrc);
        d = load8888 (dest);
        sia = expand_alpha (s);
        dia = expand_alpha (d);
@@ -878,10 +865,9 @@ mmx_combine_add_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       __m64 s, d;
-       uint32_t ssrc = combine (src, mask);
+       __m64 d;
+       __m64 s = combine (src, mask);
 
-       s = load8888 (&ssrc);
        d = load8888 (dest);
        s = pix_add (s, d);
        store8888 (dest, s);
@@ -906,12 +892,14 @@ mmx_combine_saturate_u (pixman_implementation_t *imp,
 
     while (dest < end)
     {
-       uint32_t s = combine (src, mask);
+       uint32_t s, sa, da;
        uint32_t d = *dest;
-       __m64 ms = load8888 (&s);
-       __m64 md = load8888 (&d);
-       uint32_t sa = s >> 24;
-       uint32_t da = ~d >> 24;
+       __m64 ms = combine (src, mask);
+       __m64 md = load8888 (dest);
+
+       store8888(&s, ms);
+       da = ~d >> 24;
+       sa = s >> 24;
 
        if (sa > da)
        {