nir: Store gl_shader_stage in nir_shader.
[mesa.git] / src / glsl / lower_ubo_reference.cpp
index 026197df7a9b65a0659805bf4865d82735b153dc..8b0810781fee7d63622af765c43a881745963e90 100644 (file)
 #include "ir_builder.h"
 #include "ir_rvalue_visitor.h"
 #include "main/macros.h"
+#include "glsl_parser_extras.h"
 
 using namespace ir_builder;
 
+/**
+ * Determine if a thing being dereferenced is row-major
+ *
+ * There is some trickery here.
+ *
+ * If the thing being dereferenced is a member of uniform block \b without an
+ * instance name, then the name of the \c ir_variable is the field name of an
+ * interface type.  If this field is row-major, then the thing referenced is
+ * row-major.
+ *
+ * If the thing being dereferenced is a member of uniform block \b with an
+ * instance name, then the last dereference in the tree will be an
+ * \c ir_dereference_record.  If that record field is row-major, then the
+ * thing referenced is row-major.
+ */
+static bool
+is_dereferenced_thing_row_major(const ir_dereference *deref)
+{
+   bool matrix = false;
+   const ir_rvalue *ir = deref;
+
+   while (true) {
+      matrix = matrix || ir->type->without_array()->is_matrix();
+
+      switch (ir->ir_type) {
+      case ir_type_dereference_array: {
+         const ir_dereference_array *const array_deref =
+            (const ir_dereference_array *) ir;
+
+         ir = array_deref->array;
+         break;
+      }
+
+      case ir_type_dereference_record: {
+         const ir_dereference_record *const record_deref =
+            (const ir_dereference_record *) ir;
+
+         ir = record_deref->record;
+
+         const int idx = ir->type->field_index(record_deref->field);
+         assert(idx >= 0);
+
+         const enum glsl_matrix_layout matrix_layout =
+            glsl_matrix_layout(ir->type->fields.structure[idx].matrix_layout);
+
+         switch (matrix_layout) {
+         case GLSL_MATRIX_LAYOUT_INHERITED:
+            break;
+         case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR:
+            return false;
+         case GLSL_MATRIX_LAYOUT_ROW_MAJOR:
+            return matrix || deref->type->without_array()->is_record();
+         }
+
+         break;
+      }
+
+      case ir_type_dereference_variable: {
+         const ir_dereference_variable *const var_deref =
+            (const ir_dereference_variable *) ir;
+
+         const enum glsl_matrix_layout matrix_layout =
+            glsl_matrix_layout(var_deref->var->data.matrix_layout);
+
+         switch (matrix_layout) {
+         case GLSL_MATRIX_LAYOUT_INHERITED:
+            assert(!matrix);
+            return false;
+         case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR:
+            return false;
+         case GLSL_MATRIX_LAYOUT_ROW_MAJOR:
+            return matrix || deref->type->without_array()->is_record();
+         }
+
+         unreachable("invalid matrix layout");
+         break;
+      }
+
+      default:
+         return false;
+      }
+   }
+
+   /* The tree must have ended with a dereference that wasn't an
+    * ir_dereference_variable.  That is invalid, and it should be impossible.
+    */
+   unreachable("invalid dereference tree");
+   return false;
+}
+
 namespace {
 class lower_ubo_reference_visitor : public ir_rvalue_enter_visitor {
 public:
@@ -49,16 +140,38 @@ public:
    }
 
    void handle_rvalue(ir_rvalue **rvalue);
-   void emit_ubo_loads(ir_dereference *deref, ir_variable *base_offset,
-                      unsigned int deref_offset);
+   ir_visitor_status visit_enter(ir_assignment *ir);
+
+   void setup_for_load_or_store(ir_variable *var,
+                                ir_dereference *deref,
+                                ir_rvalue **offset,
+                                unsigned *const_offset,
+                                bool *row_major,
+                                int *matrix_columns);
    ir_expression *ubo_load(const struct glsl_type *type,
                           ir_rvalue *offset);
+   ir_call *ssbo_load(const struct glsl_type *type,
+                      ir_rvalue *offset);
+
+   void check_for_ssbo_store(ir_assignment *ir);
+   void write_to_memory(ir_dereference *deref,
+                        ir_variable *var,
+                        ir_variable *write_var,
+                        unsigned write_mask);
+   ir_call *ssbo_store(ir_rvalue *deref, ir_rvalue *offset,
+                       unsigned write_mask);
+
+   void emit_access(bool is_write, ir_dereference *deref,
+                    ir_variable *base_offset, unsigned int deref_offset,
+                    bool row_major, int matrix_columns,
+                    unsigned write_mask);
 
    void *mem_ctx;
    struct gl_shader *shader;
    struct gl_uniform_buffer_variable *ubo_var;
-   unsigned uniform_block;
+   ir_rvalue *uniform_block;
    bool progress;
+   bool is_shader_storage;
 };
 
 /**
@@ -69,9 +182,11 @@ public:
  * \c UniformBlocks array.
  */
 static const char *
-interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
+interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d,
+                     ir_rvalue **nonconst_block_index)
 {
-   ir_constant *previous_index = NULL;
+   ir_rvalue *previous_index = NULL;
+   *nonconst_block_index = NULL;
 
    while (d != NULL) {
       switch (d->ir_type) {
@@ -79,13 +194,21 @@ interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
          ir_dereference_variable *v = (ir_dereference_variable *) d;
          if (previous_index
              && v->var->is_interface_instance()
-             && v->var->type->is_array())
-            return ralloc_asprintf(mem_ctx,
-                                   "%s[%d]",
-                                   base_name,
-                                   previous_index->get_uint_component(0));
-         else
+             && v->var->type->is_array()) {
+
+            ir_constant *const_index = previous_index->as_constant();
+            if (!const_index) {
+               *nonconst_block_index = previous_index;
+               return ralloc_asprintf(mem_ctx, "%s[0]", base_name);
+            } else {
+               return ralloc_asprintf(mem_ctx,
+                                      "%s[%d]",
+                                      base_name,
+                                      const_index->get_uint_component(0));
+            }
+         } else {
             return base_name;
+         }
 
          break;
       }
@@ -101,7 +224,8 @@ interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
          ir_dereference_array *a = (ir_dereference_array *) d;
 
          d = a->array->as_dereference();
-         previous_index = a->array_index->as_constant();
+         previous_index = a->array_index;
+
          break;
       }
 
@@ -116,43 +240,51 @@ interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
 }
 
 void
-lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
+lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var,
+                                                     ir_dereference *deref,
+                                                     ir_rvalue **offset,
+                                                     unsigned *const_offset,
+                                                     bool *row_major,
+                                                     int *matrix_columns)
 {
-   if (!*rvalue)
-      return;
-
-   ir_dereference *deref = (*rvalue)->as_dereference();
-   if (!deref)
-      return;
-
-   ir_variable *var = deref->variable_referenced();
-   if (!var || !var->is_in_uniform_block())
-      return;
-
-   mem_ctx = ralloc_parent(*rvalue);
-
+   /* Determine the name of the interface block */
+   ir_rvalue *nonconst_block_index;
    const char *const field_name =
-      interface_field_name(mem_ctx, (char *) var->interface_type->name, deref);
+      interface_field_name(mem_ctx, (char *) var->get_interface_type()->name,
+                           deref, &nonconst_block_index);
 
-   this->uniform_block = -1;
+   /* Locate the ubo block by interface name */
+   this->uniform_block = NULL;
    for (unsigned i = 0; i < shader->NumUniformBlocks; i++) {
       if (strcmp(field_name, shader->UniformBlocks[i].Name) == 0) {
-         this->uniform_block = i;
+
+         ir_constant *index = new(mem_ctx) ir_constant(i);
+
+         if (nonconst_block_index) {
+            if (nonconst_block_index->type != glsl_type::uint_type)
+               nonconst_block_index = i2u(nonconst_block_index);
+            this->uniform_block = add(nonconst_block_index, index);
+         } else {
+            this->uniform_block = index;
+         }
+
+         this->is_shader_storage = shader->UniformBlocks[i].IsShaderStorage;
 
          struct gl_uniform_block *block = &shader->UniformBlocks[i];
 
          this->ubo_var = var->is_interface_instance()
-            ? &block->Uniforms[0] : &block->Uniforms[var->location];
+            ? &block->Uniforms[0] : &block->Uniforms[var->data.location];
 
          break;
       }
    }
 
-   assert(this->uniform_block != (unsigned) -1);
+   assert(this->uniform_block);
 
-   ir_rvalue *offset = new(mem_ctx) ir_constant(0u);
-   unsigned const_offset = 0;
-   bool row_major = ubo_var->RowMajor;
+   *offset = new(mem_ctx) ir_constant(0u);
+   *const_offset = 0;
+   *row_major = is_dereferenced_thing_row_major(deref);
+   *matrix_columns = 1;
 
    /* Calculate the offset to the start of the region of the UBO
     * dereferenced by *rvalue.  This may be a variable offset if an
@@ -161,80 +293,146 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
    while (deref) {
       switch (deref->ir_type) {
       case ir_type_dereference_variable: {
-        const_offset += ubo_var->Offset;
-        deref = NULL;
-        break;
+         *const_offset += ubo_var->Offset;
+         deref = NULL;
+         break;
       }
 
       case ir_type_dereference_array: {
-        ir_dereference_array *deref_array = (ir_dereference_array *)deref;
-        unsigned array_stride;
-        if (deref_array->array->type->is_matrix() && row_major) {
-           /* When loading a vector out of a row major matrix, the
-            * step between the columns (vectors) is the size of a
-            * float, while the step between the rows (elements of a
-            * vector) is handled below in emit_ubo_loads.
-            */
-           array_stride = 4;
+         ir_dereference_array *deref_array = (ir_dereference_array *) deref;
+         unsigned array_stride;
+         if (deref_array->array->type->is_matrix() && *row_major) {
+            /* When loading a vector out of a row major matrix, the
+             * step between the columns (vectors) is the size of a
+             * float, while the step between the rows (elements of a
+             * vector) is handled below in emit_ubo_loads.
+             */
+            array_stride = 4;
+            if (deref_array->array->type->is_double())
+               array_stride *= 2;
+            *matrix_columns = deref_array->array->type->matrix_columns;
          } else if (deref_array->type->is_interface()) {
             /* We're processing an array dereference of an interface instance
-            * array.  The thing being dereferenced *must* be a variable
-            * dereference because intefaces cannot be embedded an other
-            * types.  In terms of calculating the offsets for the lowering
-            * pass, we don't care about the array index.  All elements of an
-            * interface instance array will have the same offsets relative to
-            * the base of the block that backs them.
+             * array. The thing being dereferenced *must* be a variable
+             * dereference because interfaces cannot be embedded in other
+             * types. In terms of calculating the offsets for the lowering
+             * pass, we don't care about the array index. All elements of an
+             * interface instance array will have the same offsets relative to
+             * the base of the block that backs them.
              */
             assert(deref_array->array->as_dereference_variable());
             deref = deref_array->array->as_dereference();
             break;
-        } else {
-           array_stride = deref_array->type->std140_size(row_major);
-           array_stride = glsl_align(array_stride, 16);
-        }
-
-        ir_constant *const_index = deref_array->array_index->as_constant();
-        if (const_index) {
-           const_offset += array_stride * const_index->value.i[0];
-        } else {
-           offset = add(offset,
-                        mul(deref_array->array_index,
-                            new(mem_ctx) ir_constant(array_stride)));
-        }
-        deref = deref_array->array->as_dereference();
-        break;
+         } else {
+            /* Whether or not the field is row-major (because it might be a
+             * bvec2 or something) does not affect the array itself. We need
+             * to know whether an array element in its entirety is row-major.
+             */
+            const bool array_row_major =
+               is_dereferenced_thing_row_major(deref_array);
+
+            array_stride = deref_array->type->std140_size(array_row_major);
+            array_stride = glsl_align(array_stride, 16);
+         }
+
+         ir_rvalue *array_index = deref_array->array_index;
+         if (array_index->type->base_type == GLSL_TYPE_INT)
+            array_index = i2u(array_index);
+
+         ir_constant *const_index =
+            array_index->constant_expression_value(NULL);
+         if (const_index) {
+            *const_offset += array_stride * const_index->value.u[0];
+         } else {
+            *offset = add(*offset,
+                          mul(array_index,
+                              new(mem_ctx) ir_constant(array_stride)));
+         }
+         deref = deref_array->array->as_dereference();
+         break;
       }
 
       case ir_type_dereference_record: {
-        ir_dereference_record *deref_record = (ir_dereference_record *)deref;
-        const glsl_type *struct_type = deref_record->record->type;
-        unsigned intra_struct_offset = 0;
-
-        unsigned max_field_align = 16;
-        for (unsigned int i = 0; i < struct_type->length; i++) {
-           const glsl_type *type = struct_type->fields.structure[i].type;
-           unsigned field_align = type->std140_base_alignment(row_major);
-           max_field_align = MAX2(field_align, max_field_align);
-           intra_struct_offset = glsl_align(intra_struct_offset, field_align);
-
-           if (strcmp(struct_type->fields.structure[i].name,
-                      deref_record->field) == 0)
-              break;
-           intra_struct_offset += type->std140_size(row_major);
-        }
-
-        const_offset = glsl_align(const_offset, max_field_align);
-        const_offset += intra_struct_offset;
-
-        deref = deref_record->record->as_dereference();
-        break;
+         ir_dereference_record *deref_record = (ir_dereference_record *) deref;
+         const glsl_type *struct_type = deref_record->record->type;
+         unsigned intra_struct_offset = 0;
+
+         for (unsigned int i = 0; i < struct_type->length; i++) {
+            const glsl_type *type = struct_type->fields.structure[i].type;
+
+            ir_dereference_record *field_deref = new(mem_ctx)
+               ir_dereference_record(deref_record->record,
+                                     struct_type->fields.structure[i].name);
+            const bool field_row_major =
+               is_dereferenced_thing_row_major(field_deref);
+
+            ralloc_free(field_deref);
+
+            unsigned field_align = type->std140_base_alignment(field_row_major);
+
+            intra_struct_offset = glsl_align(intra_struct_offset, field_align);
+
+            if (strcmp(struct_type->fields.structure[i].name,
+                       deref_record->field) == 0)
+               break;
+
+            intra_struct_offset += type->std140_size(field_row_major);
+
+            /* If the field just examined was itself a structure, apply rule
+             * #9:
+             *
+             *     "The structure may have padding at the end; the base offset
+             *     of the member following the sub-structure is rounded up to
+             *     the next multiple of the base alignment of the structure."
+             */
+            if (type->without_array()->is_record()) {
+               intra_struct_offset = glsl_align(intra_struct_offset,
+                                                field_align);
+
+            }
+         }
+
+         *const_offset += intra_struct_offset;
+         deref = deref_record->record->as_dereference();
+         break;
       }
+
       default:
-        assert(!"not reached");
-        deref = NULL;
-        break;
+         assert(!"not reached");
+         deref = NULL;
+         break;
       }
    }
+}
+
+void
+lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
+{
+   if (!*rvalue)
+      return;
+
+   ir_dereference *deref = (*rvalue)->as_dereference();
+   if (!deref)
+      return;
+
+   ir_variable *var = deref->variable_referenced();
+   if (!var || !var->is_in_buffer_block())
+      return;
+
+   mem_ctx = ralloc_parent(shader->ir);
+
+   ir_rvalue *offset = NULL;
+   unsigned const_offset;
+   bool row_major;
+   int matrix_columns;
+
+   /* Compute the offset to the start if the dereference as well as other
+    * information we need to configure the write
+    */
+   setup_for_load_or_store(var, deref,
+                           &offset, &const_offset,
+                           &row_major, &matrix_columns);
+   assert(offset);
 
    /* Now that we've calculated the offset to the start of the
     * dereference, walk over the type and emit loads into a temporary.
@@ -252,7 +450,8 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
    base_ir->insert_before(assign(load_offset, offset));
 
    deref = new(mem_ctx) ir_dereference_variable(load_var);
-   emit_ubo_loads(deref, load_offset, const_offset);
+   emit_access(false, deref, load_offset, const_offset,
+               row_major, matrix_columns, 0);
    *rvalue = deref;
 
    progress = true;
@@ -262,116 +461,326 @@ ir_expression *
 lower_ubo_reference_visitor::ubo_load(const glsl_type *type,
                                      ir_rvalue *offset)
 {
+   ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL);
    return new(mem_ctx)
       ir_expression(ir_binop_ubo_load,
-                   type,
-                   new(mem_ctx) ir_constant(this->uniform_block),
-                   offset);
+                    type,
+                    block_ref,
+                    offset);
+
+}
+
+static bool
+shader_storage_buffer_object(const _mesa_glsl_parse_state *state)
+{
+   return state->ARB_shader_storage_buffer_object_enable;
+}
+
+ir_call *
+lower_ubo_reference_visitor::ssbo_store(ir_rvalue *deref,
+                                        ir_rvalue *offset,
+                                        unsigned write_mask)
+{
+   exec_list sig_params;
+
+   ir_variable *block_ref = new(mem_ctx)
+      ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in);
+   sig_params.push_tail(block_ref);
+
+   ir_variable *offset_ref = new(mem_ctx)
+      ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in);
+   sig_params.push_tail(offset_ref);
+
+   ir_variable *val_ref = new(mem_ctx)
+      ir_variable(deref->type, "value" , ir_var_function_in);
+   sig_params.push_tail(val_ref);
+
+   ir_variable *writemask_ref = new(mem_ctx)
+      ir_variable(glsl_type::uint_type, "write_mask" , ir_var_function_in);
+   sig_params.push_tail(writemask_ref);
+
+   ir_function_signature *sig = new(mem_ctx)
+      ir_function_signature(glsl_type::void_type, shader_storage_buffer_object);
+   assert(sig);
+   sig->replace_parameters(&sig_params);
+   sig->is_intrinsic = true;
+
+   ir_function *f = new(mem_ctx) ir_function("__intrinsic_store_ssbo");
+   f->add_signature(sig);
+
+   exec_list call_params;
+   call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL));
+   call_params.push_tail(offset->clone(mem_ctx, NULL));
+   call_params.push_tail(deref->clone(mem_ctx, NULL));
+   call_params.push_tail(new(mem_ctx) ir_constant(write_mask));
+   return new(mem_ctx) ir_call(sig, NULL, &call_params);
+}
+
+ir_call *
+lower_ubo_reference_visitor::ssbo_load(const struct glsl_type *type,
+                                       ir_rvalue *offset)
+{
+   exec_list sig_params;
+
+   ir_variable *block_ref = new(mem_ctx)
+      ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in);
+   sig_params.push_tail(block_ref);
+
+   ir_variable *offset_ref = new(mem_ctx)
+      ir_variable(glsl_type::uint_type, "offset_ref" , ir_var_function_in);
+   sig_params.push_tail(offset_ref);
+
+   ir_function_signature *sig =
+      new(mem_ctx) ir_function_signature(type, shader_storage_buffer_object);
+   assert(sig);
+   sig->replace_parameters(&sig_params);
+   sig->is_intrinsic = true;
 
+   ir_function *f = new(mem_ctx) ir_function("__intrinsic_load_ssbo");
+   f->add_signature(sig);
+
+   ir_variable *result = new(mem_ctx)
+      ir_variable(type, "ssbo_load_result", ir_var_temporary);
+   base_ir->insert_before(result);
+   ir_dereference_variable *deref_result = new(mem_ctx)
+      ir_dereference_variable(result);
+
+   exec_list call_params;
+   call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL));
+   call_params.push_tail(offset->clone(mem_ctx, NULL));
+
+   return new(mem_ctx) ir_call(sig, deref_result, &call_params);
+}
+
+static inline int
+writemask_for_size(unsigned n)
+{
+   return ((1 << n) - 1);
 }
 
 /**
- * Takes LHS and emits a series of assignments into its components
- * from the UBO variable at variable_offset + deref_offset.
- *
- * Recursively calls itself to break the deref down to the point that
- * the ir_binop_ubo_load expressions generated are contiguous scalars
- * or vectors.
+ * Takes a deref and recursively calls itself to break the deref down to the
+ * point that the reads or writes generated are contiguous scalars or vectors.
  */
 void
-lower_ubo_reference_visitor::emit_ubo_loads(ir_dereference *deref,
-                                           ir_variable *base_offset,
-                                           unsigned int deref_offset)
+lower_ubo_reference_visitor::emit_access(bool is_write,
+                                         ir_dereference *deref,
+                                         ir_variable *base_offset,
+                                         unsigned int deref_offset,
+                                         bool row_major,
+                                         int matrix_columns,
+                                         unsigned write_mask)
 {
    if (deref->type->is_record()) {
       unsigned int field_offset = 0;
 
       for (unsigned i = 0; i < deref->type->length; i++) {
-        const struct glsl_struct_field *field =
-           &deref->type->fields.structure[i];
-        ir_dereference *field_deref =
-           new(mem_ctx) ir_dereference_record(deref->clone(mem_ctx, NULL),
-                                              field->name);
-
-        field_offset =
-           glsl_align(field_offset,
-                      field->type->std140_base_alignment(ubo_var->RowMajor));
-
-        emit_ubo_loads(field_deref, base_offset, deref_offset + field_offset);
-
-        field_offset += field->type->std140_size(ubo_var->RowMajor);
+         const struct glsl_struct_field *field =
+            &deref->type->fields.structure[i];
+         ir_dereference *field_deref =
+            new(mem_ctx) ir_dereference_record(deref->clone(mem_ctx, NULL),
+                                               field->name);
+
+         field_offset =
+            glsl_align(field_offset,
+                       field->type->std140_base_alignment(row_major));
+
+         emit_access(is_write, field_deref, base_offset,
+                     deref_offset + field_offset,
+                     row_major, 1,
+                     writemask_for_size(field_deref->type->vector_elements));
+
+         field_offset += field->type->std140_size(row_major);
       }
       return;
    }
 
    if (deref->type->is_array()) {
       unsigned array_stride =
-        glsl_align(deref->type->fields.array->std140_size(ubo_var->RowMajor),
-                   16);
+         glsl_align(deref->type->fields.array->std140_size(row_major), 16);
 
       for (unsigned i = 0; i < deref->type->length; i++) {
-        ir_constant *element = new(mem_ctx) ir_constant(i);
-        ir_dereference *element_deref =
-           new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL),
-                                             element);
-        emit_ubo_loads(element_deref, base_offset,
-                       deref_offset + i * array_stride);
+         ir_constant *element = new(mem_ctx) ir_constant(i);
+         ir_dereference *element_deref =
+            new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL),
+                                              element);
+         emit_access(is_write, element_deref, base_offset,
+                     deref_offset + i * array_stride,
+                     row_major, 1,
+                     writemask_for_size(element_deref->type->vector_elements));
       }
       return;
    }
 
    if (deref->type->is_matrix()) {
       for (unsigned i = 0; i < deref->type->matrix_columns; i++) {
-        ir_constant *col = new(mem_ctx) ir_constant(i);
-        ir_dereference *col_deref =
-           new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL),
-                                             col);
-
-        /* std140 always rounds the stride of arrays (and matrices)
-         * to a vec4, so matrices are always 16 between columns/rows.
-         */
-        emit_ubo_loads(col_deref, base_offset, deref_offset + i * 16);
+         ir_constant *col = new(mem_ctx) ir_constant(i);
+         ir_dereference *col_deref =
+            new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL), col);
+
+         if (row_major) {
+            /* For a row-major matrix, the next column starts at the next
+             * element.
+             */
+            int size_mul = deref->type->is_double() ? 8 : 4;
+            emit_access(is_write, col_deref, base_offset,
+                        deref_offset + i * size_mul,
+                        row_major, deref->type->matrix_columns,
+                        writemask_for_size(col_deref->type->vector_elements));
+         } else {
+            /* std140 always rounds the stride of arrays (and matrices) to a
+             * vec4, so matrices are always 16 between columns/rows. With
+             * doubles, they will be 32 apart when there are more than 2 rows.
+             */
+            int size_mul = (deref->type->is_double() &&
+                            deref->type->vector_elements > 2) ? 32 : 16;
+            emit_access(is_write, col_deref, base_offset,
+                        deref_offset + i * size_mul,
+                        row_major, deref->type->matrix_columns,
+                        writemask_for_size(col_deref->type->vector_elements));
+         }
       }
       return;
    }
 
-   assert(deref->type->is_scalar() ||
-         deref->type->is_vector());
-
-   if (!ubo_var->RowMajor) {
-      ir_rvalue *offset = add(base_offset,
-                             new(mem_ctx) ir_constant(deref_offset));
-      base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
-                                   ubo_load(deref->type, offset)));
+   assert(deref->type->is_scalar() || deref->type->is_vector());
+
+   if (!row_major) {
+      ir_rvalue *offset =
+         add(base_offset, new(mem_ctx) ir_constant(deref_offset));
+      if (is_write)
+         base_ir->insert_after(ssbo_store(deref, offset, write_mask));
+      else {
+         if (!this->is_shader_storage) {
+             base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
+                                           ubo_load(deref->type, offset)));
+         } else {
+            ir_call *load_ssbo = ssbo_load(deref->type, offset);
+            base_ir->insert_before(load_ssbo);
+            ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL);
+            base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), value));
+         }
+      }
    } else {
+      unsigned N = deref->type->is_double() ? 8 : 4;
+
       /* We're dereffing a column out of a row-major matrix, so we
        * gather the vector from each stored row.
       */
-      assert(deref->type->base_type == GLSL_TYPE_FLOAT);
+      assert(deref->type->base_type == GLSL_TYPE_FLOAT ||
+             deref->type->base_type == GLSL_TYPE_DOUBLE);
       /* Matrices, row_major or not, are stored as if they were
        * arrays of vectors of the appropriate size in std140.
        * Arrays have their strides rounded up to a vec4, so the
-       * matrix stride is always 16.
+       * matrix stride is always 16. However a double matrix may either be 16
+       * or 32 depending on the number of columns.
        */
-      unsigned matrix_stride = 16;
+      assert(matrix_columns <= 4);
+      unsigned matrix_stride = glsl_align(matrix_columns * N, 16);
+
+      const glsl_type *deref_type = deref->type->base_type == GLSL_TYPE_FLOAT ?
+         glsl_type::float_type : glsl_type::double_type;
 
       for (unsigned i = 0; i < deref->type->vector_elements; i++) {
-        ir_rvalue *chan = new(mem_ctx) ir_constant((int)i);
-        ir_dereference *deref_chan =
-           new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL),
-                                             chan);
-
-        ir_rvalue *chan_offset =
-           add(base_offset,
-               new(mem_ctx) ir_constant(deref_offset + i * matrix_stride));
-
-        base_ir->insert_before(assign(deref_chan,
-                                      ubo_load(glsl_type::float_type,
-                                               chan_offset)));
+         ir_rvalue *chan_offset =
+            add(base_offset,
+                new(mem_ctx) ir_constant(deref_offset + i * matrix_stride));
+         if (is_write) {
+            base_ir->insert_after(ssbo_store(swizzle(deref, i, 1), chan_offset, 1));
+         } else {
+            if (!this->is_shader_storage) {
+               base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
+                                             ubo_load(deref_type, chan_offset),
+                                             (1U << i)));
+            } else {
+               ir_call *load_ssbo = ssbo_load(deref_type, chan_offset);
+               base_ir->insert_before(load_ssbo);
+               ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL);
+               base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
+                                             value,
+                                             (1U << i)));
+            }
+         }
       }
    }
 }
 
+void
+lower_ubo_reference_visitor::write_to_memory(ir_dereference *deref,
+                                             ir_variable *var,
+                                             ir_variable *write_var,
+                                             unsigned write_mask)
+{
+   ir_rvalue *offset = NULL;
+   unsigned const_offset;
+   bool row_major;
+   int matrix_columns;
+
+   /* Compute the offset to the start if the dereference as well as other
+    * information we need to configure the write
+    */
+   setup_for_load_or_store(var, deref,
+                           &offset, &const_offset,
+                           &row_major, &matrix_columns);
+   assert(offset);
+
+   /* Now emit writes from the temporary to memory */
+   ir_variable *write_offset =
+      new(mem_ctx) ir_variable(glsl_type::uint_type,
+                               "ssbo_store_temp_offset",
+                               ir_var_temporary);
+
+   base_ir->insert_before(write_offset);
+   base_ir->insert_before(assign(write_offset, offset));
+
+   deref = new(mem_ctx) ir_dereference_variable(write_var);
+   emit_access(true, deref, write_offset, const_offset,
+               row_major, matrix_columns, write_mask);
+}
+
+void
+lower_ubo_reference_visitor::check_for_ssbo_store(ir_assignment *ir)
+{
+   if (!ir || !ir->lhs)
+      return;
+
+   ir_rvalue *rvalue = ir->lhs->as_rvalue();
+   if (!rvalue)
+      return;
+
+   ir_dereference *deref = ir->lhs->as_dereference();
+   if (!deref)
+      return;
+
+   ir_variable *var = ir->lhs->variable_referenced();
+   if (!var || !var->is_in_buffer_block())
+      return;
+
+   /* We have a write to a buffer variable, so declare a temporary and rewrite
+    * the assignment so that the temporary is the LHS.
+    */
+   mem_ctx = ralloc_parent(shader->ir);
+
+   const glsl_type *type = rvalue->type;
+   ir_variable *write_var = new(mem_ctx) ir_variable(type,
+                                                     "ssbo_store_temp",
+                                                     ir_var_temporary);
+   base_ir->insert_before(write_var);
+   ir->lhs = new(mem_ctx) ir_dereference_variable(write_var);
+
+   /* Now we have to write the value assigned to the temporary back to memory */
+   write_to_memory(deref, var, write_var, ir->write_mask);
+   progress = true;
+}
+
+
+ir_visitor_status
+lower_ubo_reference_visitor::visit_enter(ir_assignment *ir)
+{
+   check_for_ssbo_store(ir);
+   return rvalue_visit(ir);
+}
+
 } /* unnamed namespace */
 
 void