Attachment 98008 Details for Bug 77957 – First cut at a patch to implement lowering const arrays to uniforms

[patch] First cut at a patch to implement lowering const arrays to uniforms

0001-glsl-Lower-constant-arrays-to-uniform-arrays.patch (text/plain), 6.04 KB, created by Kenneth Graunke on 2014-04-26 08:12:30 UTC

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Creator: Kenneth Graunke

Created: 2014-04-26 08:12:30 UTC

Size: 6.04 KB

patch

obsolete

>From 7b1f97ce5d74b04221db6da29fb31fe500335c73 Mon Sep 17 00:00:00 2001
>From: Kenneth Graunke <kenneth@whitecape.org>
>Date: Sat, 26 Apr 2014 00:18:54 -0700
>Subject: [PATCH] glsl: Lower constant arrays to uniform arrays.
>
>XXX: We should probably make this optional; I don't know if other
>     drivers want it or not.  Probably worth asking on mesa-dev.
>
>XXX: Not sure about the max_array_access code.  without it, the uniform
>     gets chopped down to length 1 for some reason.
>
>XXX: This changes the const-ness of the expression.  Is that a problem?
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77957
>Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
>---
> src/glsl/Makefile.sources                   |   1 +
> src/glsl/ir_optimization.h                  |   1 +
> src/glsl/linker.cpp                         |   2 +
> src/glsl/lower_const_arrays_to_uniforms.cpp | 101 ++++++++++++++++++++++++++++
> 4 files changed, 105 insertions(+)
> create mode 100644 src/glsl/lower_const_arrays_to_uniforms.cpp
>
>diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
>index 5945590..9ec2f25 100644
>--- a/src/glsl/Makefile.sources
>+++ b/src/glsl/Makefile.sources
>@@ -59,6 +59,7 @@ LIBGLSL_FILES = \
> 	$(GLSL_SRCDIR)/loop_analysis.cpp \
> 	$(GLSL_SRCDIR)/loop_controls.cpp \
> 	$(GLSL_SRCDIR)/loop_unroll.cpp \
>+	$(GLSL_SRCDIR)/lower_const_arrays_to_uniforms.cpp \
> 	$(GLSL_SRCDIR)/lower_clip_distance.cpp \
> 	$(GLSL_SRCDIR)/lower_discard.cpp \
> 	$(GLSL_SRCDIR)/lower_discard_flow.cpp \
>diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
>index 40bb613..0bcaf86 100644
>--- a/src/glsl/ir_optimization.h
>+++ b/src/glsl/ir_optimization.h
>@@ -108,6 +108,7 @@ bool lower_noise(exec_list *instructions);
> bool lower_variable_index_to_cond_assign(exec_list *instructions,
>     bool lower_input, bool lower_output, bool lower_temp, bool lower_uniform);
> bool lower_quadop_vector(exec_list *instructions, bool dont_lower_swz);
>+bool lower_const_arrays_to_uniforms(exec_list *instructions);
> bool lower_clip_distance(gl_shader *shader);
> void lower_output_reads(exec_list *instructions);
> bool lower_packing_builtins(exec_list *instructions, int op_mask);
>diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
>index c2f7f48..fd5035b 100644
>--- a/src/glsl/linker.cpp
>+++ b/src/glsl/linker.cpp
>@@ -2300,6 +2300,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
>                                     &ctx->ShaderCompilerOptions[i],
>                                     ctx->Const.NativeIntegers))
> 	 ;
>+
>+      lower_const_arrays_to_uniforms(prog->_LinkedShaders[i]->ir);
>    }
> 
>    /* Mark all generic shader inputs and outputs as unpaired. */
>diff --git a/src/glsl/lower_const_arrays_to_uniforms.cpp b/src/glsl/lower_const_arrays_to_uniforms.cpp
>new file mode 100644
>index 0000000..516a259
>--- /dev/null
>+++ b/src/glsl/lower_const_arrays_to_uniforms.cpp
>@@ -0,0 +1,101 @@
>+/*
>+ * Copyright Â© 2014 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_const_arrays_to_uniforms.cpp
>+ *
>+ * Lower constant arrays to uniform arrays.
>+ *
>+ * Some driver backends (such as i965) don't handle constant arrays gracefully,
>+ * instead treating them as ordinary writable temporary arrays.  Since arrays
>+ * can be large, this often means spilling them to scratch memory, which
>+ * usually involves a large number of instructions.
>+ *
>+ * This must be called prior to link_set_uniform_initializers(); we need the
>+ * linker to process our new uniform's constant initializer.
>+ *
>+ * This should be called after optimizations, since those can result in
>+ * splitting and removing arrays that are indexed by constant expressions.
>+ */
>+#include "ir.h"
>+#include "ir_visitor.h"
>+#include "ir_rvalue_visitor.h"
>+#include "glsl_types.h"
>+
>+namespace {
>+class lower_const_array_visitor : public ir_rvalue_visitor {
>+public:
>+   lower_const_array_visitor(exec_list *insts)
>+   {
>+      instructions = insts;
>+      progress = false;
>+   }
>+
>+   bool run()
>+   {
>+      visit_list_elements(this, instructions);
>+      return progress;
>+   }
>+
>+   void handle_rvalue(ir_rvalue **rvalue);
>+
>+private:
>+   exec_list *instructions;
>+   bool progress;
>+};
>+
>+void
>+lower_const_array_visitor::handle_rvalue(ir_rvalue **rvalue)
>+{
>+   if (!*rvalue)
>+      return;
>+
>+   ir_constant *con = (*rvalue)->as_constant();
>+   if (!con || !con->type->is_array())
>+      return;
>+
>+   void *mem_ctx = ralloc_parent(con);
>+
>+   ir_variable *uni =
>+      new(mem_ctx) ir_variable(con->type, "constarray", ir_var_uniform);
>+   uni->constant_initializer = con;
>+   uni->constant_value = con;
>+   uni->data.has_initializer = true;
>+   uni->data.read_only = true;
>+   /* Assume the whole thing is accessed. */
>+   uni->data.max_array_access = uni->type->length - 1;
>+   instructions->push_head(uni);
>+
>+   *rvalue = new(mem_ctx) ir_dereference_variable(uni);
>+
>+   progress = true;
>+}
>+
>+} /* anonymous namespace */
>+
>+bool
>+lower_const_arrays_to_uniforms(exec_list *instructions)
>+{
>+   lower_const_array_visitor v(instructions);
>+   return v.run();
>+}
>-- 
>1.9.2
>

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