nir: move to two-level binding model for UBO's

The GLSL layer above is still hacky, so we're really just moving the
hack into GLSL-to-NIR. I'd rather not go all the way and make GLSL
support the Vulkan binding model too, since presumably we'll be
switching to SPIR-V exclusively, and so working on proper GLSL support
will be a waste of time. For now, doing this keeps it working as we add
SPIR-V->NIR support though.

3 files changed, 36 insertions, 22 deletions

diff --git a/src/glsl/nir/glsl_to_nir.cpp b/src/glsl/nir/glsl_to_nir.cpp
index 0338af67567..54e56145c89 100644
--- a/src/glsl/nir/glsl_to_nir.cpp
+++ b/src/glsl/nir/glsl_to_nir.cpp
@@ -43,7 +43,7 @@ namespace {
 class nir_visitor : public ir_visitor
 {
 public:
-   nir_visitor(nir_shader *shader, gl_shader_stage stage);
+   nir_visitor(nir_shader *shader, struct gl_shader *sh, gl_shader_stage stage);
    ~nir_visitor();
 
    virtual void visit(ir_variable *);
@@ -83,6 +83,8 @@ private:
 
    bool supports_ints;
 
+   struct gl_shader *sh;
+
    nir_shader *shader;
    gl_shader_stage stage;
    nir_function_impl *impl;
@@ -133,7 +135,7 @@ glsl_to_nir(struct gl_shader *sh, const nir_shader_compiler_options *options)
 {
    nir_shader *shader = nir_shader_create(NULL, options);
 
-   nir_visitor v1(shader, sh->Stage);
+   nir_visitor v1(shader, sh, sh->Stage);
    nir_function_visitor v2(&v1);
    v2.run(sh->ir);
    visit_exec_list(sh->ir, &v1);
@@ -141,10 +143,12 @@ glsl_to_nir(struct gl_shader *sh, const nir_shader_compiler_options *options)
    return shader;
 }
 
-nir_visitor::nir_visitor(nir_shader *shader, gl_shader_stage stage)
+nir_visitor::nir_visitor(nir_shader *shader, struct gl_shader *sh,
+                         gl_shader_stage stage)
 {
    this->supports_ints = shader->options->native_integers;
    this->shader = shader;
+   this->sh = sh;
    this->stage = stage;
    this->is_global = true;
    this->var_table = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
@@ -987,11 +991,21 @@ nir_visitor::visit(ir_expression *ir)
       } else {
          op = nir_intrinsic_load_ubo_indirect;
       }
+
+      ir_constant *const_block = ir->operands[0]->as_constant();
+      assert(const_block && "can't figure out descriptor set index");
+      unsigned index = const_block->value.u[0];
+      unsigned set = sh->UniformBlocks[index].Set;
+      unsigned binding = sh->UniformBlocks[index].Binding;
+
       nir_intrinsic_instr *load = nir_intrinsic_instr_create(this->shader, op);
       load->num_components = ir->type->vector_elements;
-      load->const_index[0] = const_index ? const_index->value.u[0] : 0; /* base offset */
-      load->const_index[1] = 1; /* number of vec4's */
-      load->src[0] = evaluate_rvalue(ir->operands[0]);
+      load->const_index[0] = set;
+      load->const_index[1] = const_index ? const_index->value.u[0] : 0; /* base offset */
+      nir_load_const_instr *load_binding = nir_load_const_instr_create(shader, 1);
+      load_binding->value.u[0] = binding;
+      nir_instr_insert_after_cf_list(this->cf_node_list, &load_binding->instr);
+      load->src[0] = nir_src_for_ssa(&load_binding->def);
       if (!const_index)
          load->src[1] = evaluate_rvalue(ir->operands[1]);
       add_instr(&load->instr, ir->type->vector_elements);
diff --git a/src/glsl/nir/nir_intrinsics.h b/src/glsl/nir/nir_intrinsics.h
index bc6e6b8f498..64861300b55 100644
--- a/src/glsl/nir/nir_intrinsics.h
+++ b/src/glsl/nir/nir_intrinsics.h
@@ -139,11 +139,12 @@ SYSTEM_VALUE(sample_mask_in, 1)
 SYSTEM_VALUE(invocation_id, 1)
 
 /*
- * The first and only index is the base address to load from.  Indirect
- * loads have an additional register input, which is added to the constant
- * address to compute the final address to load from.  For UBO's (and
- * SSBO's), the first source is the (possibly constant) UBO buffer index
- * and the indirect (if it exists) is the second source.
+ * The last index is the base address to load from.  Indirect loads have an
+ * additional register input, which is added to the constant address to
+ * compute the final address to load from.  For UBO's (and SSBO's), the first
+ * source is the (possibly constant) UBO buffer index and the indirect (if it
+ * exists) is the second source, and the first index is the descriptor set
+ * index.
  *
  * For vector backends, the address is in terms of one vec4, and so each array
  * element is +4 scalar components from the previous array element. For scalar
@@ -151,14 +152,14 @@ SYSTEM_VALUE(invocation_id, 1)
  * elements begin immediately after the previous array element.
  */
 
-#define LOAD(name, extra_srcs, flags) \
-   INTRINSIC(load_##name, extra_srcs, ARR(1), true, 0, 0, 1, flags) \
+#define LOAD(name, extra_srcs, extra_indices, flags) \
+   INTRINSIC(load_##name, extra_srcs, ARR(1), true, 0, 0, 1 + extra_indices, flags) \
    INTRINSIC(load_##name##_indirect, extra_srcs + 1, ARR(1, 1), \
-             true, 0, 0, 1, flags)
+             true, 0, 0, 1 + extra_indices, flags)
 
-LOAD(uniform, 0, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
-LOAD(ubo, 1, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
-LOAD(input, 0, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
+LOAD(uniform, 0, 0, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
+LOAD(ubo, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
+LOAD(input, 0, 0, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
 /* LOAD(ssbo, 1, 0) */
 
 /*
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 46c30fcae26..4d98b048433 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -1364,13 +1364,12 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
       has_indirect = true;
       /* fallthrough */
    case nir_intrinsic_load_ubo: {
+      uint32_t set = instr->const_index[0];
       nir_const_value *const_index = nir_src_as_const_value(instr->src[0]);
       fs_reg surf_index;
 
       if (const_index) {
-         uint32_t index = const_index->u[0];
-         uint32_t set = shader->base.UniformBlocks[index].Set;
-         uint32_t binding = shader->base.UniformBlocks[index].Binding;
+         uint32_t binding = const_index->u[0];
 
          /* FIXME: We should probably assert here, but dota2 seems to hit
           * it and we'd like to keep going.
@@ -1405,7 +1404,7 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
                                      BRW_REGISTER_TYPE_D),
                  fs_reg(2));
 
-         unsigned vec4_offset = instr->const_index[0] / 4;
+         unsigned vec4_offset = instr->const_index[1] / 4;
          for (int i = 0; i < instr->num_components; i++)
             VARYING_PULL_CONSTANT_LOAD(bld, offset(dest, i), surf_index,
                                        base_offset, vec4_offset + i);
@@ -1413,7 +1412,7 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
          fs_reg packed_consts = vgrf(glsl_type::float_type);
          packed_consts.type = dest.type;
 
-         fs_reg const_offset_reg((unsigned) instr->const_index[0] & ~15);
+         fs_reg const_offset_reg((unsigned) instr->const_index[1] & ~15);
          bld.emit(FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD, packed_consts,
                   surf_index, const_offset_reg);