Mesa (master): cell: perform triangle cull a little earlier
Brian Paul
brianp at kemper.freedesktop.org
Thu May 21 14:19:31 UTC 2009
Module: Mesa
Branch: master
Commit: 2c007517b541ab470ad251365bd95c83002dfb16
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=2c007517b541ab470ad251365bd95c83002dfb16
Author: Jonathan Adamczewski <jadamcze at utas.edu.au>
Date: Thu May 21 08:19:00 2009 -0600
cell: perform triangle cull a little earlier
In spu_tri.c:setup_sort_vertices() triangles are culled after the
vertices are sorted. This patch moves the check a little earlier
and performs the actual check a little faster through intrinsics and
a little trickery.
Reduced code size and less work is done before a triangle is deemed
OK to skip.
---
src/gallium/drivers/cell/spu/spu_tri.c | 105 ++++++++++++++++++++++---------
1 files changed, 74 insertions(+), 31 deletions(-)
diff --git a/src/gallium/drivers/cell/spu/spu_tri.c b/src/gallium/drivers/cell/spu/spu_tri.c
index d9f5a46..58be001 100644
--- a/src/gallium/drivers/cell/spu/spu_tri.c
+++ b/src/gallium/drivers/cell/spu/spu_tri.c
@@ -133,7 +133,15 @@ struct setup_stage {
uint tx, ty; /**< position of current tile (x, y) */
- int cliprect_minx, cliprect_maxx, cliprect_miny, cliprect_maxy;
+ union {
+ struct {
+ int cliprect_minx;
+ int cliprect_miny;
+ int cliprect_maxx;
+ int cliprect_maxy;
+ };
+ qword cliprect;
+ };
struct interp_coef coef[PIPE_MAX_SHADER_INPUTS];
@@ -432,6 +440,41 @@ print_vertex(const struct vertex_header *v)
}
#endif
+/* Returns the minimum of each slot of two vec_float4s as qwords.
+ * i.e. return[n] = min(q0[n],q1[n]);
+ */
+static qword
+minfq(qword q0, qword q1)
+{
+ const qword q0q1m = si_fcgt(q0, q1);
+ return si_selb(q0, q1, q0q1m);
+}
+
+/* Returns the minimum of each slot of three vec_float4s as qwords.
+ * i.e. return[n] = min(q0[n],q1[n],q2[n]);
+ */
+static qword
+min3fq(qword q0, qword q1, qword q2)
+{
+ return minfq(minfq(q0, q1), q2);
+}
+
+/* Returns the maximum of each slot of two vec_float4s as qwords.
+ * i.e. return[n] = min(q0[n],q1[n],q2[n]);
+ */
+static qword
+maxfq(qword q0, qword q1) {
+ const qword q0q1m = si_fcgt(q0, q1);
+ return si_selb(q1, q0, q0q1m);
+}
+
+/* Returns the maximum of each slot of three vec_float4s as qwords.
+ * i.e. return[n] = min(q0[n],q1[n],q2[n]);
+ */
+static qword
+max3fq(qword q0, qword q1, qword q2) {
+ return maxfq(maxfq(q0, q1), q2);
+}
/**
* Sort vertices from top to bottom.
@@ -453,8 +496,25 @@ setup_sort_vertices(const qword vs)
}
#endif
- /* determine bottom to top order of vertices */
{
+ /* Load the float values for various processing... */
+ const qword f0 = (qword)(((const struct vertex_header*)si_to_ptr(vs))->data[0]);
+ const qword f1 = (qword)(((const struct vertex_header*)si_to_ptr(si_rotqbyi(vs, 4)))->data[0]);
+ const qword f2 = (qword)(((const struct vertex_header*)si_to_ptr(si_rotqbyi(vs, 8)))->data[0]);
+
+ /* Check if triangle is completely outside the tile bounds
+ * Find the min and max x and y positions of the three poits */
+ const qword minf = min3fq(f0, f1, f2);
+ const qword maxf = max3fq(f0, f1, f2);
+
+ /* Compare min and max against cliprect vals */
+ const qword maxsmins = si_shufb(maxf, minf, SHUFB4(A,B,a,b));
+ const qword outside = si_fcgt(maxsmins, si_csflt(setup.cliprect, 0));
+
+ /* Use a little magic to work out of the tri is visible or not */
+ if(si_to_uint(si_xori(si_gb(outside), 0xc))) return FALSE;
+
+ /* determine bottom to top order of vertices */
/* A table of shuffle patterns for putting vertex_header pointers into
correct order. Quite magical. */
const qword sort_order_patterns[] = {
@@ -467,43 +527,26 @@ setup_sort_vertices(const qword vs)
/* Collate y values into two vectors for comparison.
Using only one shuffle constant! ;) */
- const vector float f0 = ((const struct vertex_header*)si_to_ptr(vs))->data[0];
- const vector float f1 = ((const struct vertex_header*)si_to_ptr(si_rotqbyi(vs, 4)))->data[0];
- const vector float f2 = ((const struct vertex_header*)si_to_ptr(si_rotqbyi(vs, 8)))->data[0];
- const vec_float4 y_02_ = spu_shuffle(f0, f2, SHUFFLE4(0,B,b,C));
- const vec_float4 y_10_ = spu_shuffle(f1, f0, SHUFFLE4(0,B,b,C));
- const vec_float4 y_012 = spu_shuffle(y_02_, f1, SHUFFLE4(0,B,b,C));
- const vec_float4 y_120 = spu_shuffle(y_10_, f2, SHUFFLE4(0,B,b,C));
+ const qword y_02_ = si_shufb(f0, f2, SHUFB4(0,B,b,C));
+ const qword y_10_ = si_shufb(f1, f0, SHUFB4(0,B,b,C));
+ const qword y_012 = si_shufb(y_02_, f1, SHUFB4(0,B,b,C));
+ const qword y_120 = si_shufb(y_10_, f2, SHUFB4(0,B,b,C));
/* Perform comparison: {y0,y1,y2} > {y1,y2,y0} */
- const vec_uint4 compare = spu_cmpgt(y_012, y_120);
+ const qword compare = si_fcgt(y_012, y_120);
/* Compress the result of the comparison into 4 bits */
- const vec_uint4 gather = spu_gather(compare);
+ const qword gather = si_gb(compare);
/* Subtract one to attain the index into the LUT. Magical. */
- const unsigned int index = spu_extract(gather, 0) - 1;
+ const unsigned int index = si_to_uint(gather) - 1;
/* Load the appropriate pattern and construct the desired vector. */
setup.vertex_headers = si_shufb(vs, vs, sort_order_patterns[index]);
/* Using the result of the comparison, set sign.
Very magical. */
- sign = ((si_to_uint(si_cntb((qword)gather)) == 2) ? 1.0f : -1.0f);
+ sign = ((si_to_uint(si_cntb(gather)) == 2) ? 1.0f : -1.0f);
}
- /* Check if triangle is completely outside the tile bounds */
- if (spu_extract(setup.vmin->data[0], 1) > setup.cliprect_maxy)
- return FALSE;
- if (spu_extract(setup.vmax->data[0], 1) < setup.cliprect_miny)
- return FALSE;
- if (spu_extract(setup.vmin->data[0], 0) < setup.cliprect_minx &&
- spu_extract(setup.vmid->data[0], 0) < setup.cliprect_minx &&
- spu_extract(setup.vmax->data[0], 0) < setup.cliprect_minx)
- return FALSE;
- if (spu_extract(setup.vmin->data[0], 0) > setup.cliprect_maxx &&
- spu_extract(setup.vmid->data[0], 0) > setup.cliprect_maxx &&
- spu_extract(setup.vmax->data[0], 0) > setup.cliprect_maxx)
- return FALSE;
-
setup.ebot.ds = spu_sub(setup.vmid->data[0], setup.vmin->data[0]);
setup.emaj.ds = spu_sub(setup.vmax->data[0], setup.vmin->data[0]);
setup.etop.ds = spu_sub(setup.vmax->data[0], setup.vmid->data[0]);
@@ -766,10 +809,10 @@ tri_draw(const qword vs,
setup.ty = ty;
/* set clipping bounds to tile bounds */
- setup.cliprect_minx = tx * TILE_SIZE;
- setup.cliprect_miny = ty * TILE_SIZE;
- setup.cliprect_maxx = (tx + 1) * TILE_SIZE;
- setup.cliprect_maxy = (ty + 1) * TILE_SIZE;
+ const qword clipbase = (qword)((vec_uint4){tx, ty});
+ const qword clipmin = si_mpyui(clipbase, TILE_SIZE);
+ const qword clipmax = si_ai(clipmin, TILE_SIZE);
+ setup.cliprect = si_shufb(clipmin, clipmax, SHUFB4(A,B,a,b));
if(!setup_sort_vertices(vs)) {
return FALSE; /* totally clipped */
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