Mesa (master): i965: Reduce repeated calculation of the attribute-offset-in-VUE.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 09788ce10e354b3af6139c04a13b38df18632b13
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=09788ce10e354b3af6139c04a13b38df18632b13

Author: Eric Anholt <eric at anholt.net>
Date:   Mon Jul 19 16:44:38 2010 -0700

i965: Reduce repeated calculation of the attribute-offset-in-VUE.

This cleans up some chipset dependency sprinkled around, and fixes a
potential overflow of the attribute offset array for many vertex
results.

---

 src/mesa/drivers/dri/i965/brw_clip.c      |   20 +++++++++++---------
 src/mesa/drivers/dri/i965/brw_clip.h      |    5 ++++-
 src/mesa/drivers/dri/i965/brw_clip_tri.c  |    5 +----
 src/mesa/drivers/dri/i965/brw_clip_util.c |   13 +++----------
 4 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_clip.c b/src/mesa/drivers/dri/i965/brw_clip.c
index 96d278f..a1e9dae 100644
--- a/src/mesa/drivers/dri/i965/brw_clip.c
+++ b/src/mesa/drivers/dri/i965/brw_clip.c
@@ -55,6 +55,7 @@ static void compile_clip_prog( struct brw_context *brw,
    GLuint program_size;
    GLuint delta;
    GLuint i;
+   GLuint header_regs;
 
    memset(&c, 0, sizeof(c));
    
@@ -72,27 +73,28 @@ static void compile_clip_prog( struct brw_context *brw,
    c.header_position_offset = ATTR_SIZE;
 
    if (intel->gen == 5)
-       delta = 3 * REG_SIZE;
+      header_regs = 3;
    else
-       delta = REG_SIZE;
+      header_regs = 1;
 
-   for (i = 0; i < VERT_RESULT_MAX; i++)
+   delta = header_regs * REG_SIZE;
+
+   for (i = 0; i < VERT_RESULT_MAX; i++) {
       if (c.key.attrs & BITFIELD64_BIT(i)) {
 	 c.offset[i] = delta;
 	 delta += ATTR_SIZE;
-      }
 
-   c.nr_attrs = brw_count_bits(c.key.attrs);
+	 c.idx_to_attr[c.nr_attrs] = i;
+	 c.nr_attrs++;
+      }
+   }
 
    /* The vertex attributes start at a URB row-aligned offset after
     * the 8-20 dword vertex header, and continue for a URB row-aligned
     * length.  nr_regs determines the urb_read_length from the start
     * of the header to the end of the vertex data.
     */
-   if (intel->gen == 5)
-       c.nr_regs = 3 + (c.nr_attrs + 1) / 2;
-   else
-       c.nr_regs = 1 + (c.nr_attrs + 1) / 2;
+   c.nr_regs = header_regs + (c.nr_attrs + 1) / 2;
 
    c.nr_bytes = c.nr_regs * REG_SIZE;
 
diff --git a/src/mesa/drivers/dri/i965/brw_clip.h b/src/mesa/drivers/dri/i965/brw_clip.h
index 68222c6..3a8cd7b 100644
--- a/src/mesa/drivers/dri/i965/brw_clip.h
+++ b/src/mesa/drivers/dri/i965/brw_clip.h
@@ -115,7 +115,10 @@ struct brw_clip_compile {
    GLboolean need_direction;
 
    GLuint header_position_offset;
-   GLuint offset[VERT_ATTRIB_MAX];
+   /** Mapping from VERT_RESULT_* to offset within the VUE. */
+   GLuint offset[VERT_RESULT_MAX];
+   /** Mapping from attribute index to VERT_RESULT_* */
+   GLuint idx_to_attr[VERT_RESULT_MAX];
 };
 
 #define ATTR_SIZE  (4*4)
diff --git a/src/mesa/drivers/dri/i965/brw_clip_tri.c b/src/mesa/drivers/dri/i965/brw_clip_tri.c
index fd425b3..cb58d1d 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_tri.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_tri.c
@@ -76,10 +76,7 @@ void brw_clip_tri_alloc_regs( struct brw_clip_compile *c,
 
    if (c->nr_attrs & 1) {
       for (j = 0; j < 3; j++) {
-	 GLuint delta = c->nr_attrs*16 + 32;
-
-         if (intel->gen == 5)
-             delta = c->nr_attrs * 16 + 32 * 3;
+	 GLuint delta = c->offset[c->idx_to_attr[c->nr_attrs - 1]] + ATTR_SIZE;
 
 	 brw_MOV(&c->func, byte_offset(c->reg.vertex[j], delta), brw_imm_f(0));
       }
diff --git a/src/mesa/drivers/dri/i965/brw_clip_util.c b/src/mesa/drivers/dri/i965/brw_clip_util.c
index 9708d7e..a74bbc2 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_util.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_util.c
@@ -134,7 +134,6 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
 			     GLboolean force_edgeflag)
 {
    struct brw_compile *p = &c->func;
-   struct intel_context *intel = &p->brw->intel;
    struct brw_reg tmp = get_tmp(c);
    GLuint i;
 
@@ -149,12 +148,9 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
    /* Iterate over each attribute (could be done in pairs?)
     */
    for (i = 0; i < c->nr_attrs; i++) {
-      GLuint delta = i*16 + 32;
+      GLuint delta = c->offset[c->idx_to_attr[i]];
 
-      if (intel->gen == 5)
-          delta = i * 16 + 32 * 3;
-
-      if (delta == c->offset[VERT_RESULT_EDGE]) {
+      if (c->idx_to_attr[i] == VERT_RESULT_EDGE) {
 	 if (force_edgeflag) 
 	    brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1));
 	 else
@@ -183,10 +179,7 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
    }
 
    if (i & 1) {
-      GLuint delta = i*16 + 32;
-
-      if (intel->gen == 5)
-          delta = i * 16 + 32 * 3;
+      GLuint delta = c->offset[c->idx_to_attr[c->nr_attrs - 1]] + ATTR_SIZE;
 
       brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(0));
    }