[Mesa-dev] [PATCH 2/2] glsl: Add a pass to flip matrix/vector multiplies to use dot products.

Kenneth Graunke kenneth at whitecape.org
Tue Apr 2 23:33:18 PDT 2013


This pass flips (matrix * vector) operations to (vector *
matrixTranspose) for certain built-in matrices (currently
gl_ModelViewProjectionMatrix and gl_TextureMatrix).

This is equivalent, but results in dot products rather than multiplies
and adds.  On some hardware, this is more efficient.

This pass is conditionalized on ctx->mvp_with_dp4, the flag drivers set
to indicate they prefer dot products.

Improves performance in Lightsmark by 1.01131% +/- 0.162069% (n = 10)
on a Haswell GT2 system.  Passes Piglit on Ivybridge.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/glsl/Makefile.sources                  |   1 +
 src/glsl/glsl_parser_extras.cpp            |   7 +-
 src/glsl/ir_optimization.h                 |   4 +-
 src/glsl/linker.cpp                        |   2 +-
 src/glsl/main.cpp                          |   2 +-
 src/glsl/opt_flip_matrices.cpp             | 122 +++++++++++++++++++++++++++++
 src/glsl/test_optpass.cpp                  |   2 +-
 src/mesa/drivers/dri/i965/brw_shader.cpp   |   2 +-
 src/mesa/main/ff_fragment_shader.cpp       |   2 +-
 src/mesa/program/ir_to_mesa.cpp            |   5 +-
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp |   3 +-
 11 files changed, 142 insertions(+), 10 deletions(-)
 create mode 100644 src/glsl/opt_flip_matrices.cpp

diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
index c294aa4..df1e9d5 100644
--- a/src/glsl/Makefile.sources
+++ b/src/glsl/Makefile.sources
@@ -80,6 +80,7 @@ LIBGLSL_FILES = \
 	$(GLSL_SRCDIR)/opt_dead_code.cpp \
 	$(GLSL_SRCDIR)/opt_dead_code_local.cpp \
 	$(GLSL_SRCDIR)/opt_dead_functions.cpp \
+	$(GLSL_SRCDIR)/opt_flip_matrices.cpp \
 	$(GLSL_SRCDIR)/opt_function_inlining.cpp \
 	$(GLSL_SRCDIR)/opt_if_simplification.cpp \
 	$(GLSL_SRCDIR)/opt_noop_swizzle.cpp \
diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
index 9740903..e0387b8 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -1206,7 +1206,8 @@ ast_struct_specifier::ast_struct_specifier(const char *identifier,
 bool
 do_common_optimization(exec_list *ir, bool linked,
 		       bool uniform_locations_assigned,
-		       unsigned max_unroll_iterations)
+		       unsigned max_unroll_iterations,
+                       bool prefer_dp4)
 {
    GLboolean progress = GL_FALSE;
 
@@ -1220,6 +1221,10 @@ do_common_optimization(exec_list *ir, bool linked,
    progress = do_if_simplification(ir) || progress;
    progress = do_copy_propagation(ir) || progress;
    progress = do_copy_propagation_elements(ir) || progress;
+
+   if (prefer_dp4 && !linked)
+      progress = opt_flip_matrices(ir) || progress;
+
    if (linked)
       progress = do_dead_code(ir, uniform_locations_assigned) || progress;
    else
diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
index 2454bbe..b404256 100644
--- a/src/glsl/ir_optimization.h
+++ b/src/glsl/ir_optimization.h
@@ -65,7 +65,8 @@ enum lower_packing_builtins_op {
 
 bool do_common_optimization(exec_list *ir, bool linked,
 			    bool uniform_locations_assigned,
-			    unsigned max_unroll_iterations);
+			    unsigned max_unroll_iterations,
+                            bool prefer_dp4);
 
 bool do_algebraic(exec_list *instructions);
 bool do_constant_folding(exec_list *instructions);
@@ -78,6 +79,7 @@ bool do_dead_code(exec_list *instructions, bool uniform_locations_assigned);
 bool do_dead_code_local(exec_list *instructions);
 bool do_dead_code_unlinked(exec_list *instructions);
 bool do_dead_functions(exec_list *instructions);
+bool opt_flip_matrices(exec_list *instructions);
 bool do_function_inlining(exec_list *instructions);
 bool do_lower_jumps(exec_list *instructions, bool pull_out_jumps = true, bool lower_sub_return = true, bool lower_main_return = false, bool lower_continue = false, bool lower_break = false);
 bool do_lower_texture_projection(exec_list *instructions);
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 2b30d2b..67a6c5a 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -1767,7 +1767,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 
       unsigned max_unroll = ctx->ShaderCompilerOptions[i].MaxUnrollIterations;
 
-      while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false, max_unroll))
+      while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false, max_unroll, ctx->mvp_with_dp4))
 	 ;
    }
 
diff --git a/src/glsl/main.cpp b/src/glsl/main.cpp
index ce084b4..13dfdd3 100644
--- a/src/glsl/main.cpp
+++ b/src/glsl/main.cpp
@@ -176,7 +176,7 @@ compile_shader(struct gl_context *ctx, struct gl_shader *shader)
    if (!state->error && !shader->ir->is_empty()) {
       bool progress;
       do {
-	 progress = do_common_optimization(shader->ir, false, false, 32);
+	 progress = do_common_optimization(shader->ir, false, false, 32, false);
       } while (progress);
 
       validate_ir_tree(shader->ir);
diff --git a/src/glsl/opt_flip_matrices.cpp b/src/glsl/opt_flip_matrices.cpp
new file mode 100644
index 0000000..497513f
--- /dev/null
+++ b/src/glsl/opt_flip_matrices.cpp
@@ -0,0 +1,122 @@
+/*
+ * Copyright © 2013 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 opt_flip_matrices.cpp
+ *
+ * Convert (matrix * vector) operations to (vector * matrixTranspose),
+ * which can be done using dot products rather than multiplies and adds.
+ * On some hardware, this is more efficient.
+ *
+ * This currently only does the conversion for built-in matrices which
+ * already have transposed equivalents.  Namely, gl_ModelViewProjectionMatrix
+ * and gl_TextureMatrix.
+ */
+#include "ir.h"
+#include "ir_optimization.h"
+#include "main/macros.h"
+
+namespace {
+class matrix_flipper : public ir_hierarchical_visitor {
+public:
+   matrix_flipper(exec_list *instructions)
+   {
+      progress = false;
+      mvp_transpose = NULL;
+      texmat_transpose = NULL;
+
+      foreach_list(n, instructions) {
+         ir_instruction *ir = (ir_instruction *) n;
+         ir_variable *var = ir->as_variable();
+         if (!var)
+            continue;
+         if (strcmp(var->name, "gl_ModelViewProjectionMatrixTranspose") == 0)
+            mvp_transpose = var;
+         if (strcmp(var->name, "gl_TextureMatrixTranspose") == 0)
+            texmat_transpose = var;
+      }
+   }
+
+   ir_visitor_status visit_enter(ir_expression *ir);
+
+   bool progress;
+
+private:
+   ir_variable *mvp_transpose;
+   ir_variable *texmat_transpose;
+};
+}
+
+ir_visitor_status
+matrix_flipper::visit_enter(ir_expression *ir)
+{
+   if (ir->operation != ir_binop_mul ||
+       !ir->operands[0]->type->is_matrix() ||
+       !ir->operands[1]->type->is_vector())
+      return visit_continue;
+
+   ir_variable *mat_var = ir->operands[0]->variable_referenced();
+   if (!mat_var)
+      return visit_continue;
+
+   if (mvp_transpose &&
+       strcmp(mat_var->name, "gl_ModelViewProjectionMatrix") == 0) {
+      ir_dereference_variable *deref = ir->operands[0]->as_dereference_variable();
+      assert(deref && deref->var == mat_var);
+
+      void *mem_ctx = ralloc_parent(ir);
+
+      ir->operands[0] = ir->operands[1];
+      ir->operands[1] = new(mem_ctx) ir_dereference_variable(mvp_transpose);
+
+      progress = true;
+   } else if (texmat_transpose &&
+              strcmp(mat_var->name, "gl_TextureMatrix") == 0) {
+      ir_dereference_array *array_ref = ir->operands[0]->as_dereference_array();
+      assert(array_ref != NULL);
+      ir_dereference_variable *var_ref = array_ref->array->as_dereference_variable();
+      assert(var_ref && var_ref->var == mat_var);
+
+      ir->operands[0] = ir->operands[1];
+      ir->operands[1] = array_ref;
+
+      var_ref->var = texmat_transpose;
+
+      texmat_transpose->max_array_access =
+         MAX2(texmat_transpose->max_array_access, mat_var->max_array_access);
+
+      progress = true;
+   }
+
+   return visit_continue;
+}
+
+bool
+opt_flip_matrices(struct exec_list *instructions)
+{
+   matrix_flipper v(instructions);
+
+   visit_list_elements(&v, instructions);
+
+   return v.progress;
+}
diff --git a/src/glsl/test_optpass.cpp b/src/glsl/test_optpass.cpp
index 117b0b0..87c3705 100644
--- a/src/glsl/test_optpass.cpp
+++ b/src/glsl/test_optpass.cpp
@@ -64,7 +64,7 @@ do_optimization(struct exec_list *ir, const char *optimization)
 
    if (sscanf(optimization, "do_common_optimization ( %d , %d ) ",
               &int_0, &int_1) == 2) {
-      return do_common_optimization(ir, int_0 != 0, false, int_1);
+      return do_common_optimization(ir, int_0 != 0, false, int_1, false);
    } else if (strcmp(optimization, "do_algebraic") == 0) {
       return do_algebraic(ir);
    } else if (strcmp(optimization, "do_constant_folding") == 0) {
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index 1a52039..54537b1 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -207,7 +207,7 @@ brw_link_shader(struct gl_context *ctx, struct gl_shader_program *shProg)
 				   false /* loops */
 				   ) || progress;
 
-	 progress = do_common_optimization(shader->ir, true, true, 32)
+	 progress = do_common_optimization(shader->ir, true, true, 32, true)
 	   || progress;
       } while (progress);
 
diff --git a/src/mesa/main/ff_fragment_shader.cpp b/src/mesa/main/ff_fragment_shader.cpp
index 01a4542..fb45578 100644
--- a/src/mesa/main/ff_fragment_shader.cpp
+++ b/src/mesa/main/ff_fragment_shader.cpp
@@ -1336,7 +1336,7 @@ create_new_program(struct gl_context *ctx, struct state_key *key)
 
    validate_ir_tree(p.shader->ir);
 
-   while (do_common_optimization(p.shader->ir, false, false, 32))
+   while (do_common_optimization(p.shader->ir, false, false, 32, ctx->mvp_with_dp4))
       ;
    reparent_ir(p.shader->ir, p.shader->ir);
 
diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index 14cf5ba..9456571 100644
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -3012,7 +3012,8 @@ _mesa_ir_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
 	 progress = do_lower_jumps(ir, true, true, options->EmitNoMainReturn, options->EmitNoCont, options->EmitNoLoops) || progress;
 
 	 progress = do_common_optimization(ir, true, true,
-					   options->MaxUnrollIterations)
+					   options->MaxUnrollIterations,
+                                           ctx->mvp_with_dp4)
 	   || progress;
 
 	 progress = lower_quadop_vector(ir, true) || progress;
@@ -3122,7 +3123,7 @@ _mesa_glsl_compile_shader(struct gl_context *ctx, struct gl_shader *shader)
       /* Do some optimization at compile time to reduce shader IR size
        * and reduce later work if the same shader is linked multiple times
        */
-      while (do_common_optimization(shader->ir, false, false, 32))
+      while (do_common_optimization(shader->ir, false, false, 32, ctx->mvp_with_dp4))
 	 ;
 
       validate_ir_tree(shader->ir);
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 338c652..a23c705 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -5228,7 +5228,8 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
          progress = do_lower_jumps(ir, true, true, options->EmitNoMainReturn, options->EmitNoCont, options->EmitNoLoops) || progress;
 
          progress = do_common_optimization(ir, true, true,
-					   options->MaxUnrollIterations)
+					   options->MaxUnrollIterations,
+                                           ctx->mvp_with_dp4)
 	   || progress;
 
          progress = lower_if_to_cond_assign(ir, options->MaxIfDepth) || progress;
-- 
1.8.2



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