glsl: move to compiler/

Signed-off-by: Emil Velikov <[email protected]>
Acked-by: Matt Turner <[email protected]>
Acked-by: Jose Fonseca <[email protected]>

1 files changed, 496 insertions, 0 deletions

diff --git a/src/compiler/glsl/lower_shared_reference.cpp b/src/compiler/glsl/lower_shared_reference.cpp
new file mode 100644
index 00000000000..533cd9202f4
--- /dev/null
+++ b/src/compiler/glsl/lower_shared_reference.cpp
@@ -0,0 +1,496 @@
+/*
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file lower_shared_reference.cpp
+ *
+ * IR lower pass to replace dereferences of compute shader shared variables
+ * with intrinsic function calls.
+ *
+ * This relieves drivers of the responsibility of allocating space for the
+ * shared variables in the shared memory region.
+ */
+
+#include "lower_buffer_access.h"
+#include "ir_builder.h"
+#include "main/macros.h"
+#include "util/list.h"
+#include "glsl_parser_extras.h"
+
+using namespace ir_builder;
+
+namespace {
+
+struct var_offset {
+   struct list_head node;
+   const ir_variable *var;
+   unsigned offset;
+};
+
+class lower_shared_reference_visitor :
+      public lower_buffer_access::lower_buffer_access {
+public:
+
+   lower_shared_reference_visitor(struct gl_shader *shader)
+      : list_ctx(ralloc_context(NULL)), shader(shader), shared_size(0u)
+   {
+      list_inithead(&var_offsets);
+   }
+
+   ~lower_shared_reference_visitor()
+   {
+      ralloc_free(list_ctx);
+   }
+
+   enum {
+      shared_load_access,
+      shared_store_access,
+      shared_atomic_access,
+   } buffer_access_type;
+
+   void insert_buffer_access(void *mem_ctx, ir_dereference *deref,
+                             const glsl_type *type, ir_rvalue *offset,
+                             unsigned mask, int channel);
+
+   void handle_rvalue(ir_rvalue **rvalue);
+   ir_visitor_status visit_enter(ir_assignment *ir);
+   void handle_assignment(ir_assignment *ir);
+
+   ir_call *lower_shared_atomic_intrinsic(ir_call *ir);
+   ir_call *check_for_shared_atomic_intrinsic(ir_call *ir);
+   ir_visitor_status visit_enter(ir_call *ir);
+
+   unsigned get_shared_offset(const ir_variable *);
+
+   ir_call *shared_load(void *mem_ctx, const struct glsl_type *type,
+                        ir_rvalue *offset);
+   ir_call *shared_store(void *mem_ctx, ir_rvalue *deref, ir_rvalue *offset,
+                         unsigned write_mask);
+
+   void *list_ctx;
+   struct gl_shader *shader;
+   struct list_head var_offsets;
+   unsigned shared_size;
+   bool progress;
+};
+
+unsigned
+lower_shared_reference_visitor::get_shared_offset(const ir_variable *var)
+{
+   list_for_each_entry(var_offset, var_entry, &var_offsets, node) {
+      if (var_entry->var == var)
+         return var_entry->offset;
+   }
+
+   struct var_offset *new_entry = rzalloc(list_ctx, struct var_offset);
+   list_add(&new_entry->node, &var_offsets);
+   new_entry->var = var;
+
+   unsigned var_align = var->type->std430_base_alignment(false);
+   new_entry->offset = glsl_align(shared_size, var_align);
+
+   unsigned var_size = var->type->std430_size(false);
+   shared_size = new_entry->offset + var_size;
+
+   return new_entry->offset;
+}
+
+void
+lower_shared_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->data.mode != ir_var_shader_shared)
+      return;
+
+   buffer_access_type = shared_load_access;
+
+   void *mem_ctx = ralloc_parent(shader->ir);
+
+   ir_rvalue *offset = NULL;
+   unsigned const_offset = get_shared_offset(var);
+   bool row_major;
+   int matrix_columns;
+   assert(var->get_interface_type() == NULL);
+   const unsigned packing = GLSL_INTERFACE_PACKING_STD430;
+
+   setup_buffer_access(mem_ctx, var, deref,
+                       &offset, &const_offset,
+                       &row_major, &matrix_columns, packing);
+
+   /* Now that we've calculated the offset to the start of the
+    * dereference, walk over the type and emit loads into a temporary.
+    */
+   const glsl_type *type = (*rvalue)->type;
+   ir_variable *load_var = new(mem_ctx) ir_variable(type,
+                                                    "shared_load_temp",
+                                                    ir_var_temporary);
+   base_ir->insert_before(load_var);
+
+   ir_variable *load_offset = new(mem_ctx) ir_variable(glsl_type::uint_type,
+                                                       "shared_load_temp_offset",
+                                                       ir_var_temporary);
+   base_ir->insert_before(load_offset);
+   base_ir->insert_before(assign(load_offset, offset));
+
+   deref = new(mem_ctx) ir_dereference_variable(load_var);
+
+   emit_access(mem_ctx, false, deref, load_offset, const_offset, row_major,
+               matrix_columns, packing, 0);
+
+   *rvalue = deref;
+
+   progress = true;
+}
+
+void
+lower_shared_reference_visitor::handle_assignment(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->data.mode != ir_var_shader_shared)
+      return;
+
+   buffer_access_type = shared_store_access;
+
+   /* We have a write to a shared variable, so declare a temporary and rewrite
+    * the assignment so that the temporary is the LHS.
+    */
+   void *mem_ctx = ralloc_parent(shader->ir);
+
+   const glsl_type *type = rvalue->type;
+   ir_variable *store_var = new(mem_ctx) ir_variable(type,
+                                                     "shared_store_temp",
+                                                     ir_var_temporary);
+   base_ir->insert_before(store_var);
+   ir->lhs = new(mem_ctx) ir_dereference_variable(store_var);
+
+   ir_rvalue *offset = NULL;
+   unsigned const_offset = get_shared_offset(var);
+   bool row_major;
+   int matrix_columns;
+   assert(var->get_interface_type() == NULL);
+   const unsigned packing = GLSL_INTERFACE_PACKING_STD430;
+
+   setup_buffer_access(mem_ctx, var, deref,
+                       &offset, &const_offset,
+                       &row_major, &matrix_columns, packing);
+
+   deref = new(mem_ctx) ir_dereference_variable(store_var);
+
+   ir_variable *store_offset = new(mem_ctx) ir_variable(glsl_type::uint_type,
+                                                        "shared_store_temp_offset",
+                                                        ir_var_temporary);
+   base_ir->insert_before(store_offset);
+   base_ir->insert_before(assign(store_offset, offset));
+
+   /* Now we have to write the value assigned to the temporary back to memory */
+   emit_access(mem_ctx, true, deref, store_offset, const_offset, row_major,
+               matrix_columns, packing, ir->write_mask);
+
+   progress = true;
+}
+
+ir_visitor_status
+lower_shared_reference_visitor::visit_enter(ir_assignment *ir)
+{
+   handle_assignment(ir);
+   return rvalue_visit(ir);
+}
+
+void
+lower_shared_reference_visitor::insert_buffer_access(void *mem_ctx,
+                                                     ir_dereference *deref,
+                                                     const glsl_type *type,
+                                                     ir_rvalue *offset,
+                                                     unsigned mask,
+                                                     int channel)
+{
+   if (buffer_access_type == shared_store_access) {
+      ir_call *store = shared_store(mem_ctx, deref, offset, mask);
+      base_ir->insert_after(store);
+   } else {
+      ir_call *load = shared_load(mem_ctx, type, offset);
+      base_ir->insert_before(load);
+      ir_rvalue *value = load->return_deref->as_rvalue()->clone(mem_ctx, NULL);
+      base_ir->insert_before(assign(deref->clone(mem_ctx, NULL),
+                                    value));
+   }
+}
+
+static bool
+compute_shader_enabled(const _mesa_glsl_parse_state *state)
+{
+   return state->stage == MESA_SHADER_COMPUTE;
+}
+
+ir_call *
+lower_shared_reference_visitor::shared_store(void *mem_ctx,
+                                             ir_rvalue *deref,
+                                             ir_rvalue *offset,
+                                             unsigned write_mask)
+{
+   exec_list sig_params;
+
+   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, compute_shader_enabled);
+   assert(sig);
+   sig->replace_parameters(&sig_params);
+   sig->is_intrinsic = true;
+
+   ir_function *f = new(mem_ctx) ir_function("__intrinsic_store_shared");
+   f->add_signature(sig);
+
+   exec_list call_params;
+   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_shared_reference_visitor::shared_load(void *mem_ctx,
+                                            const struct glsl_type *type,
+                                            ir_rvalue *offset)
+{
+   exec_list sig_params;
+
+   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, compute_shader_enabled);
+   assert(sig);
+   sig->replace_parameters(&sig_params);
+   sig->is_intrinsic = true;
+
+   ir_function *f = new(mem_ctx) ir_function("__intrinsic_load_shared");
+   f->add_signature(sig);
+
+   ir_variable *result = new(mem_ctx)
+      ir_variable(type, "shared_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(offset->clone(mem_ctx, NULL));
+
+   return new(mem_ctx) ir_call(sig, deref_result, &call_params);
+}
+
+/* Lowers the intrinsic call to a new internal intrinsic that swaps the access
+ * to the shared variable in the first parameter by an offset. This involves
+ * creating the new internal intrinsic (i.e. the new function signature).
+ */
+ir_call *
+lower_shared_reference_visitor::lower_shared_atomic_intrinsic(ir_call *ir)
+{
+   /* Shared atomics usually have 2 parameters, the shared variable and an
+    * integer argument. The exception is CompSwap, that has an additional
+    * integer parameter.
+    */
+   int param_count = ir->actual_parameters.length();
+   assert(param_count == 2 || param_count == 3);
+
+   /* First argument must be a scalar integer shared variable */
+   exec_node *param = ir->actual_parameters.get_head();
+   ir_instruction *inst = (ir_instruction *) param;
+   assert(inst->ir_type == ir_type_dereference_variable ||
+          inst->ir_type == ir_type_dereference_array ||
+          inst->ir_type == ir_type_dereference_record ||
+          inst->ir_type == ir_type_swizzle);
+
+   ir_rvalue *deref = (ir_rvalue *) inst;
+   assert(deref->type->is_scalar() && deref->type->is_integer());
+
+   ir_variable *var = deref->variable_referenced();
+   assert(var);
+
+   /* Compute the offset to the start if the dereference
+    */
+   void *mem_ctx = ralloc_parent(shader->ir);
+
+   ir_rvalue *offset = NULL;
+   unsigned const_offset = get_shared_offset(var);
+   bool row_major;
+   int matrix_columns;
+   assert(var->get_interface_type() == NULL);
+   const unsigned packing = GLSL_INTERFACE_PACKING_STD430;
+   buffer_access_type = shared_atomic_access;
+
+   setup_buffer_access(mem_ctx, var, deref,
+                       &offset, &const_offset,
+                       &row_major, &matrix_columns, packing);
+
+   assert(offset);
+   assert(!row_major);
+   assert(matrix_columns == 1);
+
+   ir_rvalue *deref_offset =
+      add(offset, new(mem_ctx) ir_constant(const_offset));
+
+   /* Create the new internal function signature that will take an offset
+    * instead of a shared variable
+    */
+   exec_list sig_params;
+   ir_variable *sig_param = new(mem_ctx)
+      ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in);
+   sig_params.push_tail(sig_param);
+
+   const glsl_type *type = deref->type->base_type == GLSL_TYPE_INT ?
+      glsl_type::int_type : glsl_type::uint_type;
+   sig_param = new(mem_ctx)
+         ir_variable(type, "data1", ir_var_function_in);
+   sig_params.push_tail(sig_param);
+
+   if (param_count == 3) {
+      sig_param = new(mem_ctx)
+            ir_variable(type, "data2", ir_var_function_in);
+      sig_params.push_tail(sig_param);
+   }
+
+   ir_function_signature *sig =
+      new(mem_ctx) ir_function_signature(deref->type,
+                                         compute_shader_enabled);
+   assert(sig);
+   sig->replace_parameters(&sig_params);
+   sig->is_intrinsic = true;
+
+   char func_name[64];
+   sprintf(func_name, "%s_shared", ir->callee_name());
+   ir_function *f = new(mem_ctx) ir_function(func_name);
+   f->add_signature(sig);
+
+   /* Now, create the call to the internal intrinsic */
+   exec_list call_params;
+   call_params.push_tail(deref_offset);
+   param = ir->actual_parameters.get_head()->get_next();
+   ir_rvalue *param_as_rvalue = ((ir_instruction *) param)->as_rvalue();
+   call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL));
+   if (param_count == 3) {
+      param = param->get_next();
+      param_as_rvalue = ((ir_instruction *) param)->as_rvalue();
+      call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL));
+   }
+   ir_dereference_variable *return_deref =
+      ir->return_deref->clone(mem_ctx, NULL);
+   return new(mem_ctx) ir_call(sig, return_deref, &call_params);
+}
+
+ir_call *
+lower_shared_reference_visitor::check_for_shared_atomic_intrinsic(ir_call *ir)
+{
+   exec_list& params = ir->actual_parameters;
+
+   if (params.length() < 2 || params.length() > 3)
+      return ir;
+
+   ir_rvalue *rvalue =
+      ((ir_instruction *) params.get_head())->as_rvalue();
+   if (!rvalue)
+      return ir;
+
+   ir_variable *var = rvalue->variable_referenced();
+   if (!var || var->data.mode != ir_var_shader_shared)
+      return ir;
+
+   const char *callee = ir->callee_name();
+   if (!strcmp("__intrinsic_atomic_add", callee) ||
+       !strcmp("__intrinsic_atomic_min", callee) ||
+       !strcmp("__intrinsic_atomic_max", callee) ||
+       !strcmp("__intrinsic_atomic_and", callee) ||
+       !strcmp("__intrinsic_atomic_or", callee) ||
+       !strcmp("__intrinsic_atomic_xor", callee) ||
+       !strcmp("__intrinsic_atomic_exchange", callee) ||
+       !strcmp("__intrinsic_atomic_comp_swap", callee)) {
+      return lower_shared_atomic_intrinsic(ir);
+   }
+
+   return ir;
+}
+
+ir_visitor_status
+lower_shared_reference_visitor::visit_enter(ir_call *ir)
+{
+   ir_call *new_ir = check_for_shared_atomic_intrinsic(ir);
+   if (new_ir != ir) {
+      progress = true;
+      base_ir->replace_with(new_ir);
+      return visit_continue_with_parent;
+   }
+
+   return rvalue_visit(ir);
+}
+
+} /* unnamed namespace */
+
+void
+lower_shared_reference(struct gl_shader *shader, unsigned *shared_size)
+{
+   if (shader->Stage != MESA_SHADER_COMPUTE)
+      return;
+
+   lower_shared_reference_visitor v(shader);
+
+   /* Loop over the instructions lowering references, because we take a deref
+    * of an shared variable array using a shared variable dereference as the
+    * index will produce a collection of instructions all of which have cloned
+    * shared variable dereferences for that array index.
+    */
+   do {
+      v.progress = false;
+      visit_list_elements(&v, shader->ir);
+   } while (v.progress);
+
+   *shared_size = v.shared_size;
+}