llvmpipe: remove all traces of step arrays, pos_tables

No need to calculate these values any longer, nor to store them in the
bin data.  Improves isosurf a bit more, 115->123 fps.

src/gallium/drivers/llvmpipe/lp_rast.h

@@ -104,9 +104,6 @@ struct lp_rast_plane {
 
    int dcdx;
    int dcdy;
-   
-   /* edge/step info for 3 edges and 4x4 block of pixels */
-   const int *step;
 };
 
 /**
@@ -119,8 +116,6 @@ struct lp_rast_triangle {
    /* inputs for the shader */
    struct lp_rast_shader_inputs inputs;
 
-   int step[3][16];
-
 #ifdef DEBUG
    float v[3][2];
 #endif

src/gallium/drivers/llvmpipe/lp_rast_tri.c

@@ -37,52 +37,6 @@
 #include "lp_tile_soa.h"
 
 
-/**
- * Map an index in [0,15] to an x,y position, multiplied by 4.
- * This is used to get the position of each subtile in a 4x4
- * grid of edge step values.
- * Note: we can use some bit twiddling to compute these values instead
- * of using a look-up table, but there's no measurable performance
- * difference.
- */
-static const int pos_table4[16][2] = {
-   { 0, 0 },
-   { 4, 0 },
-   { 0, 4 },
-   { 4, 4 },
-   { 8, 0 },
-   { 12, 0 },
-   { 8, 4 },
-   { 12, 4 },
-   { 0, 8 },
-   { 4, 8 },
-   { 0, 12 },
-   { 4, 12 },
-   { 8, 8 },
-   { 12, 8 },
-   { 8, 12 },
-   { 12, 12 }
-};
-
-
-static const int pos_table16[16][2] = {
-   { 0, 0 },
-   { 16, 0 },
-   { 0, 16 },
-   { 16, 16 },
-   { 32, 0 },
-   { 48, 0 },
-   { 32, 16 },
-   { 48, 16 },
-   { 0, 32 },
-   { 16, 32 },
-   { 0, 48 },
-   { 16, 48 },
-   { 32, 32 },
-   { 48, 32 },
-   { 32, 48 },
-   { 48, 48 }
-};
 
 
 /**

src/gallium/drivers/llvmpipe/lp_setup_tri.c

@@ -61,36 +61,6 @@ struct tri_info {
 
 
 
-static const int step_scissor_minx[16] = {
-   0, 1, 0, 1,
-   2, 3, 2, 3,
-   0, 1, 0, 1,
-   2, 3, 2, 3
-};
-
-static const int step_scissor_maxx[16] = {
-    0, -1,  0, -1,
-   -2, -3, -2, -3,
-    0, -1,  0, -1,
-   -2, -3, -2, -3
-};
-
-static const int step_scissor_miny[16] = {
-   0, 0, 1, 1,
-   0, 0, 1, 1,
-   2, 2, 3, 3,
-   2, 2, 3, 3
-};
-
-static const int step_scissor_maxy[16] = {
-    0,  0, -1, -1,
-    0,  0, -1, -1,
-   -2, -2, -3, -3,
-   -2, -2, -3, -3
-};
-
-
-
    
 static INLINE int
 subpixel_snap(float a)
@@ -618,35 +588,6 @@ do_triangle_ccw(struct lp_setup_context *setup,
       /* Calculate trivial accept offsets from the above.
        */
       plane->ei = plane->dcdy - plane->dcdx - plane->eo;
-
-      plane->step = tri->step[i];
-
-      /* Fill in the inputs.step[][] arrays.
-       * We've manually unrolled some loops here.
-       */
-#define SETUP_STEP(j, x, y) \
-      tri->step[i][j] = y * plane->dcdy - x * plane->dcdx
-      
-      SETUP_STEP(0, 0, 0);
-      SETUP_STEP(1, 1, 0);
-      SETUP_STEP(2, 0, 1);
-      SETUP_STEP(3, 1, 1);
-
-      SETUP_STEP(4, 2, 0);
-      SETUP_STEP(5, 3, 0);
-      SETUP_STEP(6, 2, 1);
-      SETUP_STEP(7, 3, 1);
-
-      SETUP_STEP(8, 0, 2);
-      SETUP_STEP(9, 1, 2);
-      SETUP_STEP(10, 0, 3);
-      SETUP_STEP(11, 1, 3);
-
-      SETUP_STEP(12, 2, 2);
-      SETUP_STEP(13, 3, 2);
-      SETUP_STEP(14, 2, 3);
-      SETUP_STEP(15, 3, 3);
-#undef STEP
    }
 
 
@@ -669,28 +610,24 @@ do_triangle_ccw(struct lp_setup_context *setup,
     * these planes elsewhere.
     */
    if (nr_planes == 7) {
-      tri->plane[3].step = step_scissor_minx;
       tri->plane[3].dcdx = -1;
       tri->plane[3].dcdy = 0;
       tri->plane[3].c = 1-minx;
       tri->plane[3].ei = 0;
       tri->plane[3].eo = 1;
 
-      tri->plane[4].step = step_scissor_maxx;
       tri->plane[4].dcdx = 1;
       tri->plane[4].dcdy = 0;
       tri->plane[4].c = maxx;
       tri->plane[4].ei = -1;
       tri->plane[4].eo = 0;
 
-      tri->plane[5].step = step_scissor_miny;
       tri->plane[5].dcdx = 0;
       tri->plane[5].dcdy = 1;
       tri->plane[5].c = 1-miny;
       tri->plane[5].ei = 0;
       tri->plane[5].eo = 1;
 
-      tri->plane[6].step = step_scissor_maxy;
       tri->plane[6].dcdx = 0;
       tri->plane[6].dcdy = -1;
       tri->plane[6].c = maxy;