gallium: implement ARB_texture_query_levels

The extension is always supported if GLSL 1.30 is supported.

Softpipe and llvmpipe support is also added (trivial).
Radeon and nouveau support is already done.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>

docs/GL3.txt

@@ -172,7 +172,7 @@ GL 4.3:
   GL_ARB_shader_storage_buffer_object                  not started
   GL_ARB_stencil_texturing                             DONE (i965/gen8+, nv50, nvc0, r600, radeonsi)
   GL_ARB_texture_buffer_range                          DONE (nv50, nvc0, i965, r600, radeonsi)
-  GL_ARB_texture_query_levels                          DONE (i965)
+  GL_ARB_texture_query_levels                          DONE (all drivers that support GLSL 1.30)
   GL_ARB_texture_storage_multisample                   DONE (all drivers that support GL_ARB_texture_multisample)
   GL_ARB_texture_view                                  DONE (i965)
   GL_ARB_vertex_attrib_binding                         DONE (all drivers)

docs/relnotes/10.3.html

@@ -50,6 +50,7 @@ Note: some of the new features are only available with certain drivers.
 <li>GL_ARB_stencil_texturing on nv50, nvc0, r600, and radeonsi</li>
 <li>GL_ARB_texture_cube_map_array on radeonsi</li>
 <li>GL_ARB_texture_gather on radeonsi</li>
+<li>GL_ARB_texture_query_levels on nv50, nvc0, llvmpipe, r600, radeonsi, softpipe</li>
 <li>GL_ARB_viewport_array on nvc0</li>
 </ul>
 

src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c

@@ -2445,7 +2445,7 @@ emit_size_query( struct lp_build_tgsi_soa_context *bld,
                                  bld->bld_base.base.gallivm,
                                  bld->bld_base.int_bld.type,
                                  unit, pipe_target,
-                                 is_sviewinfo,
+                                 TRUE,
                                  lod_property,
                                  explicit_lod,
                                  sizes_out);

src/gallium/docs/source/tgsi.rst

@@ -964,7 +964,9 @@ XXX doesn't look like most of the opcodes really belong here.
 
   As per NV_gpu_program4, retrieve the dimensions of the texture depending on
   the target. For 1D (width), 2D/RECT/CUBE (width, height), 3D (width, height,
-  depth), 1D array (width, layers), 2D array (width, height, layers)
+  depth), 1D array (width, layers), 2D array (width, height, layers).
+  Also return the number of accessible levels (last_level - first_level + 1)
+  in W.
 
 .. math::
 
@@ -976,6 +978,8 @@ XXX doesn't look like most of the opcodes really belong here.
 
   dst.z = texture\_depth(unit, lod)
 
+  dst.w = texture\_levels(unit)
+
 .. opcode:: TG4 - Texture Gather
 
   As per ARB_texture_gather, gathers the four texels to be used in a bi-linear

src/gallium/drivers/softpipe/sp_tex_sample.c

@@ -2911,6 +2911,9 @@ sp_get_dims(struct sp_sampler_view *sp_sview, int level,
    if (level > view->u.tex.last_level)
       return;
 
+   if (texture->target != PIPE_BUFFER)
+      dims[3] = view->u.tex.last_level - view->u.tex.first_level + 1;
+
    dims[0] = u_minify(texture->width0, level);
 
    switch(texture->target) {

src/mesa/state_tracker/st_extensions.c

@@ -631,6 +631,7 @@ void st_init_extensions(struct st_context *st)
       ctx->Extensions.ARB_shading_language_packing = GL_TRUE;
       ctx->Extensions.OES_depth_texture_cube_map = GL_TRUE;
       ctx->Extensions.ARB_shading_language_420pack = GL_TRUE;
+      ctx->Extensions.ARB_texture_query_levels = GL_TRUE;
 
       if (!st->options.disable_shader_bit_encoding) {
          ctx->Extensions.ARB_shader_bit_encoding = GL_TRUE;

src/mesa/state_tracker/st_glsl_to_tgsi.cpp

@@ -2779,7 +2779,9 @@ glsl_to_tgsi_visitor::visit(ir_call *ir)
 void
 glsl_to_tgsi_visitor::visit(ir_texture *ir)
 {
-   st_src_reg result_src, coord, cube_sc, lod_info, projector, dx, dy, offset[MAX_GLSL_TEXTURE_OFFSET], sample_index, component;
+   st_src_reg result_src, coord, cube_sc, lod_info, projector, dx, dy;
+   st_src_reg offset[MAX_GLSL_TEXTURE_OFFSET], sample_index, component;
+   st_src_reg levels_src;
    st_dst_reg result_dst, coord_dst, cube_sc_dst;
    glsl_to_tgsi_instruction *inst = NULL;
    unsigned opcode = TGSI_OPCODE_NOP;
@@ -2860,6 +2862,11 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
       ir->lod_info.lod->accept(this);
       lod_info = this->result;
       break;
+   case ir_query_levels:
+      opcode = TGSI_OPCODE_TXQ;
+      lod_info = st_src_reg(PROGRAM_IMMEDIATE, 0, GLSL_TYPE_INT);
+      levels_src = get_temp(ir->type);
+      break;
    case ir_txf:
       opcode = TGSI_OPCODE_TXF;
       ir->lod_info.lod->accept(this);
@@ -2896,9 +2903,6 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
    case ir_lod:
       opcode = TGSI_OPCODE_LODQ;
       break;
-   case ir_query_levels:
-      assert(!"Unexpected ir_query_levels opcode");
-      break;
    }
 
    if (ir->projector) {
@@ -2995,9 +2999,16 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
 
    if (opcode == TGSI_OPCODE_TXD)
       inst = emit(ir, opcode, result_dst, coord, dx, dy);
-   else if (opcode == TGSI_OPCODE_TXQ)
-      inst = emit(ir, opcode, result_dst, lod_info);
-   else if (opcode == TGSI_OPCODE_TXF) {
+   else if (opcode == TGSI_OPCODE_TXQ) {
+      if (ir->op == ir_query_levels) {
+         /* the level is stored in W */
+         inst = emit(ir, opcode, st_dst_reg(levels_src), lod_info);
+         result_dst.writemask = WRITEMASK_X;
+         levels_src.swizzle = SWIZZLE_WWWW;
+         emit(ir, TGSI_OPCODE_MOV, result_dst, levels_src);
+      } else
+         inst = emit(ir, opcode, result_dst, lod_info);
+   } else if (opcode == TGSI_OPCODE_TXF) {
       inst = emit(ir, opcode, result_dst, coord);
    } else if (opcode == TGSI_OPCODE_TXL2 || opcode == TGSI_OPCODE_TXB2) {
       inst = emit(ir, opcode, result_dst, coord, lod_info);