[Mesa-dev] [PATCH 21/36] glsl: Add lowering pass for shared variable references
Jordan Justen
jordan.l.justen at intel.com
Sat Nov 14 13:43:57 PST 2015
In this lowering pass, shared variables are decomposed into intrinsic
calls.
Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
src/glsl/Makefile.sources | 1 +
src/glsl/ir_optimization.h | 1 +
src/glsl/linker.cpp | 4 +
src/glsl/lower_shared_reference.cpp | 360 ++++++++++++++++++++++++++++++++++++
src/mesa/main/mtypes.h | 7 +
5 files changed, 373 insertions(+)
create mode 100644 src/glsl/lower_shared_reference.cpp
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
index f2c95c0..4f20c0f 100644
--- a/src/glsl/Makefile.sources
+++ b/src/glsl/Makefile.sources
@@ -180,6 +180,7 @@ LIBGLSL_FILES = \
lower_vector_insert.cpp \
lower_vertex_id.cpp \
lower_output_reads.cpp \
+ lower_shared_reference.cpp \
lower_ubo_reference.cpp \
opt_algebraic.cpp \
opt_array_splitting.cpp \
diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
index 2fee81c..dabd80a 100644
--- a/src/glsl/ir_optimization.h
+++ b/src/glsl/ir_optimization.h
@@ -124,6 +124,7 @@ bool lower_const_arrays_to_uniforms(exec_list *instructions);
bool lower_clip_distance(gl_shader *shader);
void lower_output_reads(unsigned stage, exec_list *instructions);
bool lower_packing_builtins(exec_list *instructions, int op_mask);
+void lower_shared_reference(struct gl_shader *shader, unsigned *shared_size);
void lower_ubo_reference(struct gl_shader *shader);
void lower_packed_varyings(void *mem_ctx,
unsigned locations_used, ir_variable_mode mode,
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index db00f8f..dedcf77 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -4452,6 +4452,10 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
if (ctx->Const.ShaderCompilerOptions[i].LowerBufferInterfaceBlocks)
lower_ubo_reference(prog->_LinkedShaders[i]);
+ if (ctx->Const.ShaderCompilerOptions[i].LowerShaderSharedVariables)
+ lower_shared_reference(prog->_LinkedShaders[i],
+ &prog->Comp.SharedSize);
+
lower_vector_derefs(prog->_LinkedShaders[i]);
}
diff --git a/src/glsl/lower_shared_reference.cpp b/src/glsl/lower_shared_reference.cpp
new file mode 100644
index 0000000..810c6b6
--- /dev/null
+++ b/src/glsl/lower_shared_reference.cpp
@@ -0,0 +1,360 @@
+/*
+ * 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 "ir.h"
+#include "ir_builder.h"
+#include "ir_rvalue_visitor.h"
+#include "main/macros.h"
+#include "util/list.h"
+#include "glsl_parser_extras.h"
+#include "lower_buffer_access.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)
+ : lower_buffer_access::lower_buffer_access(GLSL_MATRIX_LAYOUT_COLUMN_MAJOR),
+ 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(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);
+
+ unsigned get_shared_offset(const ir_variable *);
+
+ ir_call *shared_load(const struct glsl_type *type, ir_rvalue *offset);
+ ir_call *shared_store(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;
+
+ const glsl_type *iface = var->get_interface_type();
+ unsigned packing =
+ iface ? iface->interface_packing : GLSL_INTERFACE_PACKING_STD430;
+
+ unsigned var_align;
+ if (packing == GLSL_INTERFACE_PACKING_STD430)
+ var_align = var->type->std430_base_alignment(false);
+ else
+ var_align = var->type->std140_base_alignment(false);
+ new_entry->offset = glsl_align(shared_size, var_align);
+
+ unsigned var_size;
+ if (packing == GLSL_INTERFACE_PACKING_STD430)
+ var_size = var->type->std430_size(false);
+ else
+ var_size = var->type->std140_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;
+
+ mem_ctx = ralloc_parent(shader->ir);
+
+ ir_rvalue *offset = NULL;
+ unsigned const_offset = get_shared_offset(var);
+ bool row_major;
+ int matrix_columns;
+ const glsl_type *iface = var->get_interface_type();
+ unsigned packing =
+ iface ? iface->interface_packing : GLSL_INTERFACE_PACKING_STD430;
+
+ setup_buffer_access(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(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 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 *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;
+ const glsl_type *iface = var->get_interface_type();
+ unsigned packing =
+ iface ? iface->interface_packing : GLSL_INTERFACE_PACKING_STD430;
+
+ setup_buffer_access(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(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(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(deref, offset, mask);
+ base_ir->insert_after(store);
+ } else {
+ ir_call *load = shared_load(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(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(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);
+}
+
+} /* 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);
+ *shared_size = v.shared_size;
+ } while (v.progress);
+}
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 4efdf1e..46bbcfd 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2666,6 +2666,10 @@ struct gl_shader_program
* local_size_{x,y,z}. Otherwise undefined.
*/
unsigned LocalSize[3];
+ /**
+ * Size of shared variables accessed by the compute shader.
+ */
+ unsigned SharedSize;
} Comp;
/* post-link info: */
@@ -2877,6 +2881,9 @@ struct gl_shader_compiler_options
GLboolean LowerBufferInterfaceBlocks; /**< Lower UBO and SSBO access to intrinsics. */
+ GLboolean LowerShaderSharedVariables; /**< Lower compute shader shared
+ * variable access to intrinsics. */
+
const struct nir_shader_compiler_options *NirOptions;
};
--
2.6.2
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