i965/fs: Move sampler unit lookup into rescale_texcoord

The texunit variable we create and assign in nir_emit_texture gets passed
through two more layers of function calls before it gets to its sole use in
rescale_texcoord.  The best part is that we already pass the sampler into
rescale_texcoord so we can just look it up there.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/i965/brw_fs.h

@@ -205,7 +205,7 @@ public:
    void emit_interpolation_setup_gen6();
    void compute_sample_position(fs_reg dst, fs_reg int_sample_pos);
    fs_reg rescale_texcoord(fs_reg coordinate, int coord_components,
-                           bool is_rect, uint32_t sampler, int texunit);
+                           bool is_rect, uint32_t sampler);
    void emit_texture(ir_texture_opcode op,
                      const glsl_type *dest_type,
                      fs_reg coordinate, int components,
@@ -218,8 +218,7 @@ public:
                      bool is_cube_array,
                      bool is_rect,
                      uint32_t sampler,
-                     fs_reg sampler_reg,
+                     fs_reg sampler_reg);
-                     int texunit);
    fs_reg emit_mcs_fetch(const fs_reg &coordinate, unsigned components,
                          const fs_reg &sampler);
    void emit_gen6_gather_wa(uint8_t wa, fs_reg dst);

src/mesa/drivers/dri/i965/brw_fs_nir.cpp

@@ -1917,12 +1917,6 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
    unsigned sampler = instr->sampler_index;
    fs_reg sampler_reg(sampler);
 
-   /* FINISHME: We're failing to recompile our programs when the sampler is
-    * updated.  This only matters for the texture rectangle scale parameters
-    * (pre-gen6, or gen6+ with GL_CLAMP).
-    */
-   int texunit = prog->SamplerUnits[sampler];
-
    int gather_component = instr->component;
 
    bool is_rect = instr->sampler_dim == GLSL_SAMPLER_DIM_RECT;
@@ -2063,7 +2057,7 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
    emit_texture(op, dest_type, coordinate, instr->coord_components,
                 shadow_comparitor, lod, lod2, lod_components, sample_index,
                 tex_offset, mcs, gather_component,
-                is_cube_array, is_rect, sampler, sampler_reg, texunit);
+                is_cube_array, is_rect, sampler, sampler_reg);
 
    fs_reg dest = get_nir_dest(instr->dest);
    dest.type = this->result.type;

src/mesa/drivers/dri/i965/brw_fs_visitor.cpp

@@ -79,7 +79,7 @@ fs_visitor::emit_vs_system_value(int location)
 
 fs_reg
 fs_visitor::rescale_texcoord(fs_reg coordinate, int coord_components,
-                             bool is_rect, uint32_t sampler, int texunit)
+                             bool is_rect, uint32_t sampler)
 {
    bool needs_gl_clamp = true;
    fs_reg scale_x, scale_y;
@@ -93,10 +93,16 @@ fs_visitor::rescale_texcoord(fs_reg coordinate, int coord_components,
         (devinfo->gen >= 6 && (key_tex->gl_clamp_mask[0] & (1 << sampler) ||
                                key_tex->gl_clamp_mask[1] & (1 << sampler))))) {
       struct gl_program_parameter_list *params = prog->Parameters;
+
+
+      /* FINISHME: We're failing to recompile our programs when the sampler is
+       * updated.  This only matters for the texture rectangle scale
+       * parameters (pre-gen6, or gen6+ with GL_CLAMP).
+       */
       int tokens[STATE_LENGTH] = {
 	 STATE_INTERNAL,
 	 STATE_TEXRECT_SCALE,
-	 texunit,
+	 prog->SamplerUnits[sampler],
 	 0,
 	 0
       };
@@ -221,7 +227,7 @@ fs_visitor::emit_texture(ir_texture_opcode op,
                          bool is_cube_array,
                          bool is_rect,
                          uint32_t sampler,
-                         fs_reg sampler_reg, int texunit)
+                         fs_reg sampler_reg)
 {
    fs_inst *inst = NULL;
 
@@ -256,7 +262,7 @@ fs_visitor::emit_texture(ir_texture_opcode op,
        * samplers.  This should only be a problem with GL_CLAMP on Gen7.
        */
       coordinate = rescale_texcoord(coordinate, coord_components, is_rect,
-                                    sampler, texunit);
+                                    sampler);
    }
 
    /* Writemasking doesn't eliminate channels on SIMD8 texture