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, 2632 insertions, 0 deletions

diff --git a/src/compiler/glsl/ir.h b/src/compiler/glsl/ir.h
new file mode 100644
index 00000000000..bd7b5506343
--- /dev/null
+++ b/src/compiler/glsl/ir.h
@@ -0,0 +1,2632 @@
+/* -*- c++ -*- */
+/*
+ * Copyright © 2010 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.
+ */
+
+#pragma once
+#ifndef IR_H
+#define IR_H
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "util/ralloc.h"
+#include "compiler/glsl_types.h"
+#include "list.h"
+#include "ir_visitor.h"
+#include "ir_hierarchical_visitor.h"
+#include "main/mtypes.h"
+
+#ifdef __cplusplus
+
+/**
+ * \defgroup IR Intermediate representation nodes
+ *
+ * @{
+ */
+
+/**
+ * Class tags
+ *
+ * Each concrete class derived from \c ir_instruction has a value in this
+ * enumerant.  The value for the type is stored in \c ir_instruction::ir_type
+ * by the constructor.  While using type tags is not very C++, it is extremely
+ * convenient.  For example, during debugging you can simply inspect
+ * \c ir_instruction::ir_type to find out the actual type of the object.
+ *
+ * In addition, it is possible to use a switch-statement based on \c
+ * \c ir_instruction::ir_type to select different behavior for different object
+ * types.  For functions that have only slight differences for several object
+ * types, this allows writing very straightforward, readable code.
+ */
+enum ir_node_type {
+   ir_type_dereference_array,
+   ir_type_dereference_record,
+   ir_type_dereference_variable,
+   ir_type_constant,
+   ir_type_expression,
+   ir_type_swizzle,
+   ir_type_texture,
+   ir_type_variable,
+   ir_type_assignment,
+   ir_type_call,
+   ir_type_function,
+   ir_type_function_signature,
+   ir_type_if,
+   ir_type_loop,
+   ir_type_loop_jump,
+   ir_type_return,
+   ir_type_discard,
+   ir_type_emit_vertex,
+   ir_type_end_primitive,
+   ir_type_barrier,
+   ir_type_max, /**< maximum ir_type enum number, for validation */
+   ir_type_unset = ir_type_max
+};
+
+
+/**
+ * Base class of all IR instructions
+ */
+class ir_instruction : public exec_node {
+public:
+   enum ir_node_type ir_type;
+
+   /**
+    * GCC 4.7+ and clang warn when deleting an ir_instruction unless
+    * there's a virtual destructor present.  Because we almost
+    * universally use ralloc for our memory management of
+    * ir_instructions, the destructor doesn't need to do any work.
+    */
+   virtual ~ir_instruction()
+   {
+   }
+
+   /** ir_print_visitor helper for debugging. */
+   void print(void) const;
+   void fprint(FILE *f) const;
+
+   virtual void accept(ir_visitor *) = 0;
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *) = 0;
+   virtual ir_instruction *clone(void *mem_ctx,
+				 struct hash_table *ht) const = 0;
+
+   bool is_rvalue() const
+   {
+      return ir_type == ir_type_dereference_array ||
+             ir_type == ir_type_dereference_record ||
+             ir_type == ir_type_dereference_variable ||
+             ir_type == ir_type_constant ||
+             ir_type == ir_type_expression ||
+             ir_type == ir_type_swizzle ||
+             ir_type == ir_type_texture;
+   }
+
+   bool is_dereference() const
+   {
+      return ir_type == ir_type_dereference_array ||
+             ir_type == ir_type_dereference_record ||
+             ir_type == ir_type_dereference_variable;
+   }
+
+   bool is_jump() const
+   {
+      return ir_type == ir_type_loop_jump ||
+             ir_type == ir_type_return ||
+             ir_type == ir_type_discard;
+   }
+
+   /**
+    * \name IR instruction downcast functions
+    *
+    * These functions either cast the object to a derived class or return
+    * \c NULL if the object's type does not match the specified derived class.
+    * Additional downcast functions will be added as needed.
+    */
+   /*@{*/
+   #define AS_BASE(TYPE)                                \
+   class ir_##TYPE *as_##TYPE()                         \
+   {                                                    \
+      assume(this != NULL);                             \
+      return is_##TYPE() ? (ir_##TYPE *) this : NULL;   \
+   }                                                    \
+   const class ir_##TYPE *as_##TYPE() const             \
+   {                                                    \
+      assume(this != NULL);                             \
+      return is_##TYPE() ? (ir_##TYPE *) this : NULL;   \
+   }
+
+   AS_BASE(rvalue)
+   AS_BASE(dereference)
+   AS_BASE(jump)
+   #undef AS_BASE
+
+   #define AS_CHILD(TYPE) \
+   class ir_##TYPE * as_##TYPE() \
+   { \
+      assume(this != NULL);                                         \
+      return ir_type == ir_type_##TYPE ? (ir_##TYPE *) this : NULL; \
+   }                                                                      \
+   const class ir_##TYPE * as_##TYPE() const                              \
+   {                                                                      \
+      assume(this != NULL);                                               \
+      return ir_type == ir_type_##TYPE ? (const ir_##TYPE *) this : NULL; \
+   }
+   AS_CHILD(variable)
+   AS_CHILD(function)
+   AS_CHILD(dereference_array)
+   AS_CHILD(dereference_variable)
+   AS_CHILD(dereference_record)
+   AS_CHILD(expression)
+   AS_CHILD(loop)
+   AS_CHILD(assignment)
+   AS_CHILD(call)
+   AS_CHILD(return)
+   AS_CHILD(if)
+   AS_CHILD(swizzle)
+   AS_CHILD(texture)
+   AS_CHILD(constant)
+   AS_CHILD(discard)
+   #undef AS_CHILD
+   /*@}*/
+
+   /**
+    * IR equality method: Return true if the referenced instruction would
+    * return the same value as this one.
+    *
+    * This intended to be used for CSE and algebraic optimizations, on rvalues
+    * in particular.  No support for other instruction types (assignments,
+    * jumps, calls, etc.) is planned.
+    */
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+protected:
+   ir_instruction(enum ir_node_type t)
+      : ir_type(t)
+   {
+   }
+
+private:
+   ir_instruction()
+   {
+      assert(!"Should not get here.");
+   }
+};
+
+
+/**
+ * The base class for all "values"/expression trees.
+ */
+class ir_rvalue : public ir_instruction {
+public:
+   const struct glsl_type *type;
+
+   virtual ir_rvalue *clone(void *mem_ctx, struct hash_table *) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   ir_rvalue *as_rvalue_to_saturate();
+
+   virtual bool is_lvalue() const
+   {
+      return false;
+   }
+
+   /**
+    * Get the variable that is ultimately referenced by an r-value
+    */
+   virtual ir_variable *variable_referenced() const
+   {
+      return NULL;
+   }
+
+
+   /**
+    * If an r-value is a reference to a whole variable, get that variable
+    *
+    * \return
+    * Pointer to a variable that is completely dereferenced by the r-value.  If
+    * the r-value is not a dereference or the dereference does not access the
+    * entire variable (i.e., it's just one array element, struct field), \c NULL
+    * is returned.
+    */
+   virtual ir_variable *whole_variable_referenced()
+   {
+      return NULL;
+   }
+
+   /**
+    * Determine if an r-value has the value zero
+    *
+    * The base implementation of this function always returns \c false.  The
+    * \c ir_constant class over-rides this function to return \c true \b only
+    * for vector and scalar types that have all elements set to the value
+    * zero (or \c false for booleans).
+    *
+    * \sa ir_constant::has_value, ir_rvalue::is_one, ir_rvalue::is_negative_one
+    */
+   virtual bool is_zero() const;
+
+   /**
+    * Determine if an r-value has the value one
+    *
+    * The base implementation of this function always returns \c false.  The
+    * \c ir_constant class over-rides this function to return \c true \b only
+    * for vector and scalar types that have all elements set to the value
+    * one (or \c true for booleans).
+    *
+    * \sa ir_constant::has_value, ir_rvalue::is_zero, ir_rvalue::is_negative_one
+    */
+   virtual bool is_one() const;
+
+   /**
+    * Determine if an r-value has the value negative one
+    *
+    * The base implementation of this function always returns \c false.  The
+    * \c ir_constant class over-rides this function to return \c true \b only
+    * for vector and scalar types that have all elements set to the value
+    * negative one.  For boolean types, the result is always \c false.
+    *
+    * \sa ir_constant::has_value, ir_rvalue::is_zero, ir_rvalue::is_one
+    */
+   virtual bool is_negative_one() const;
+
+   /**
+    * Determine if an r-value is an unsigned integer constant which can be
+    * stored in 16 bits.
+    *
+    * \sa ir_constant::is_uint16_constant.
+    */
+   virtual bool is_uint16_constant() const { return false; }
+
+   /**
+    * Return a generic value of error_type.
+    *
+    * Allocation will be performed with 'mem_ctx' as ralloc owner.
+    */
+   static ir_rvalue *error_value(void *mem_ctx);
+
+protected:
+   ir_rvalue(enum ir_node_type t);
+};
+
+
+/**
+ * Variable storage classes
+ */
+enum ir_variable_mode {
+   ir_var_auto = 0,             /**< Function local variables and globals. */
+   ir_var_uniform,              /**< Variable declared as a uniform. */
+   ir_var_shader_storage,       /**< Variable declared as an ssbo. */
+   ir_var_shader_shared,        /**< Variable declared as shared. */
+   ir_var_shader_in,
+   ir_var_shader_out,
+   ir_var_function_in,
+   ir_var_function_out,
+   ir_var_function_inout,
+   ir_var_const_in,             /**< "in" param that must be a constant expression */
+   ir_var_system_value,         /**< Ex: front-face, instance-id, etc. */
+   ir_var_temporary,            /**< Temporary variable generated during compilation. */
+   ir_var_mode_count            /**< Number of variable modes */
+};
+
+/**
+ * Enum keeping track of how a variable was declared.  For error checking of
+ * the gl_PerVertex redeclaration rules.
+ */
+enum ir_var_declaration_type {
+   /**
+    * Normal declaration (for most variables, this means an explicit
+    * declaration.  Exception: temporaries are always implicitly declared, but
+    * they still use ir_var_declared_normally).
+    *
+    * Note: an ir_variable that represents a named interface block uses
+    * ir_var_declared_normally.
+    */
+   ir_var_declared_normally = 0,
+
+   /**
+    * Variable was explicitly declared (or re-declared) in an unnamed
+    * interface block.
+    */
+   ir_var_declared_in_block,
+
+   /**
+    * Variable is an implicitly declared built-in that has not been explicitly
+    * re-declared by the shader.
+    */
+   ir_var_declared_implicitly,
+
+   /**
+    * Variable is implicitly generated by the compiler and should not be
+    * visible via the API.
+    */
+   ir_var_hidden,
+};
+
+/**
+ * \brief Layout qualifiers for gl_FragDepth.
+ *
+ * The AMD/ARB_conservative_depth extensions allow gl_FragDepth to be redeclared
+ * with a layout qualifier.
+ */
+enum ir_depth_layout {
+    ir_depth_layout_none, /**< No depth layout is specified. */
+    ir_depth_layout_any,
+    ir_depth_layout_greater,
+    ir_depth_layout_less,
+    ir_depth_layout_unchanged
+};
+
+/**
+ * \brief Convert depth layout qualifier to string.
+ */
+const char*
+depth_layout_string(ir_depth_layout layout);
+
+/**
+ * Description of built-in state associated with a uniform
+ *
+ * \sa ir_variable::state_slots
+ */
+struct ir_state_slot {
+   int tokens[5];
+   int swizzle;
+};
+
+
+/**
+ * Get the string value for an interpolation qualifier
+ *
+ * \return The string that would be used in a shader to specify \c
+ * mode will be returned.
+ *
+ * This function is used to generate error messages of the form "shader
+ * uses %s interpolation qualifier", so in the case where there is no
+ * interpolation qualifier, it returns "no".
+ *
+ * This function should only be used on a shader input or output variable.
+ */
+const char *interpolation_string(unsigned interpolation);
+
+
+class ir_variable : public ir_instruction {
+public:
+   ir_variable(const struct glsl_type *, const char *, ir_variable_mode);
+
+   virtual ir_variable *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+
+   /**
+    * Determine how this variable should be interpolated based on its
+    * interpolation qualifier (if present), whether it is gl_Color or
+    * gl_SecondaryColor, and whether flatshading is enabled in the current GL
+    * state.
+    *
+    * The return value will always be either INTERP_QUALIFIER_SMOOTH,
+    * INTERP_QUALIFIER_NOPERSPECTIVE, or INTERP_QUALIFIER_FLAT.
+    */
+   glsl_interp_qualifier determine_interpolation_mode(bool flat_shade);
+
+   /**
+    * Determine whether or not a variable is part of a uniform or
+    * shader storage block.
+    */
+   inline bool is_in_buffer_block() const
+   {
+      return (this->data.mode == ir_var_uniform ||
+              this->data.mode == ir_var_shader_storage) &&
+             this->interface_type != NULL;
+   }
+
+   /**
+    * Determine whether or not a variable is part of a shader storage block.
+    */
+   inline bool is_in_shader_storage_block() const
+   {
+      return this->data.mode == ir_var_shader_storage &&
+             this->interface_type != NULL;
+   }
+
+   /**
+    * Determine whether or not a variable is the declaration of an interface
+    * block
+    *
+    * For the first declaration below, there will be an \c ir_variable named
+    * "instance" whose type and whose instance_type will be the same
+    *  \cglsl_type.  For the second declaration, there will be an \c ir_variable
+    * named "f" whose type is float and whose instance_type is B2.
+    *
+    * "instance" is an interface instance variable, but "f" is not.
+    *
+    * uniform B1 {
+    *     float f;
+    * } instance;
+    *
+    * uniform B2 {
+    *     float f;
+    * };
+    */
+   inline bool is_interface_instance() const
+   {
+      return this->type->without_array() == this->interface_type;
+   }
+
+   /**
+    * Set this->interface_type on a newly created variable.
+    */
+   void init_interface_type(const struct glsl_type *type)
+   {
+      assert(this->interface_type == NULL);
+      this->interface_type = type;
+      if (this->is_interface_instance()) {
+         this->u.max_ifc_array_access =
+            rzalloc_array(this, unsigned, type->length);
+      }
+   }
+
+   /**
+    * Change this->interface_type on a variable that previously had a
+    * different, but compatible, interface_type.  This is used during linking
+    * to set the size of arrays in interface blocks.
+    */
+   void change_interface_type(const struct glsl_type *type)
+   {
+      if (this->u.max_ifc_array_access != NULL) {
+         /* max_ifc_array_access has already been allocated, so make sure the
+          * new interface has the same number of fields as the old one.
+          */
+         assert(this->interface_type->length == type->length);
+      }
+      this->interface_type = type;
+   }
+
+   /**
+    * Change this->interface_type on a variable that previously had a
+    * different, and incompatible, interface_type. This is used during
+    * compilation to handle redeclaration of the built-in gl_PerVertex
+    * interface block.
+    */
+   void reinit_interface_type(const struct glsl_type *type)
+   {
+      if (this->u.max_ifc_array_access != NULL) {
+#ifndef NDEBUG
+         /* Redeclaring gl_PerVertex is only allowed if none of the built-ins
+          * it defines have been accessed yet; so it's safe to throw away the
+          * old max_ifc_array_access pointer, since all of its values are
+          * zero.
+          */
+         for (unsigned i = 0; i < this->interface_type->length; i++)
+            assert(this->u.max_ifc_array_access[i] == 0);
+#endif
+         ralloc_free(this->u.max_ifc_array_access);
+         this->u.max_ifc_array_access = NULL;
+      }
+      this->interface_type = NULL;
+      init_interface_type(type);
+   }
+
+   const glsl_type *get_interface_type() const
+   {
+      return this->interface_type;
+   }
+
+   /**
+    * Get the max_ifc_array_access pointer
+    *
+    * A "set" function is not needed because the array is dynmically allocated
+    * as necessary.
+    */
+   inline unsigned *get_max_ifc_array_access()
+   {
+      assert(this->data._num_state_slots == 0);
+      return this->u.max_ifc_array_access;
+   }
+
+   inline unsigned get_num_state_slots() const
+   {
+      assert(!this->is_interface_instance()
+             || this->data._num_state_slots == 0);
+      return this->data._num_state_slots;
+   }
+
+   inline void set_num_state_slots(unsigned n)
+   {
+      assert(!this->is_interface_instance()
+             || n == 0);
+      this->data._num_state_slots = n;
+   }
+
+   inline ir_state_slot *get_state_slots()
+   {
+      return this->is_interface_instance() ? NULL : this->u.state_slots;
+   }
+
+   inline const ir_state_slot *get_state_slots() const
+   {
+      return this->is_interface_instance() ? NULL : this->u.state_slots;
+   }
+
+   inline ir_state_slot *allocate_state_slots(unsigned n)
+   {
+      assert(!this->is_interface_instance());
+
+      this->u.state_slots = ralloc_array(this, ir_state_slot, n);
+      this->data._num_state_slots = 0;
+
+      if (this->u.state_slots != NULL)
+         this->data._num_state_slots = n;
+
+      return this->u.state_slots;
+   }
+
+   inline bool is_name_ralloced() const
+   {
+      return this->name != ir_variable::tmp_name;
+   }
+
+   /**
+    * Enable emitting extension warnings for this variable
+    */
+   void enable_extension_warning(const char *extension);
+
+   /**
+    * Get the extension warning string for this variable
+    *
+    * If warnings are not enabled, \c NULL is returned.
+    */
+   const char *get_extension_warning() const;
+
+   /**
+    * Declared type of the variable
+    */
+   const struct glsl_type *type;
+
+   /**
+    * Declared name of the variable
+    */
+   const char *name;
+
+   struct ir_variable_data {
+
+      /**
+       * Is the variable read-only?
+       *
+       * This is set for variables declared as \c const, shader inputs,
+       * and uniforms.
+       */
+      unsigned read_only:1;
+      unsigned centroid:1;
+      unsigned sample:1;
+      unsigned patch:1;
+      unsigned invariant:1;
+      unsigned precise:1;
+
+      /**
+       * Has this variable been used for reading or writing?
+       *
+       * Several GLSL semantic checks require knowledge of whether or not a
+       * variable has been used.  For example, it is an error to redeclare a
+       * variable as invariant after it has been used.
+       *
+       * This is only maintained in the ast_to_hir.cpp path, not in
+       * Mesa's fixed function or ARB program paths.
+       */
+      unsigned used:1;
+
+      /**
+       * Has this variable been statically assigned?
+       *
+       * This answers whether the variable was assigned in any path of
+       * the shader during ast_to_hir.  This doesn't answer whether it is
+       * still written after dead code removal, nor is it maintained in
+       * non-ast_to_hir.cpp (GLSL parsing) paths.
+       */
+      unsigned assigned:1;
+
+      /**
+       * When separate shader programs are enabled, only input/outputs between
+       * the stages of a multi-stage separate program can be safely removed
+       * from the shader interface. Other input/outputs must remains active.
+       */
+      unsigned always_active_io:1;
+
+      /**
+       * Enum indicating how the variable was declared.  See
+       * ir_var_declaration_type.
+       *
+       * This is used to detect certain kinds of illegal variable redeclarations.
+       */
+      unsigned how_declared:2;
+
+      /**
+       * Storage class of the variable.
+       *
+       * \sa ir_variable_mode
+       */
+      unsigned mode:4;
+
+      /**
+       * Interpolation mode for shader inputs / outputs
+       *
+       * \sa ir_variable_interpolation
+       */
+      unsigned interpolation:2;
+
+      /**
+       * \name ARB_fragment_coord_conventions
+       * @{
+       */
+      unsigned origin_upper_left:1;
+      unsigned pixel_center_integer:1;
+      /*@}*/
+
+      /**
+       * Was the location explicitly set in the shader?
+       *
+       * If the location is explicitly set in the shader, it \b cannot be changed
+       * by the linker or by the API (e.g., calls to \c glBindAttribLocation have
+       * no effect).
+       */
+      unsigned explicit_location:1;
+      unsigned explicit_index:1;
+
+      /**
+       * Was an initial binding explicitly set in the shader?
+       *
+       * If so, constant_value contains an integer ir_constant representing the
+       * initial binding point.
+       */
+      unsigned explicit_binding:1;
+
+      /**
+       * Does this variable have an initializer?
+       *
+       * This is used by the linker to cross-validiate initializers of global
+       * variables.
+       */
+      unsigned has_initializer:1;
+
+      /**
+       * Is this variable a generic output or input that has not yet been matched
+       * up to a variable in another stage of the pipeline?
+       *
+       * This is used by the linker as scratch storage while assigning locations
+       * to generic inputs and outputs.
+       */
+      unsigned is_unmatched_generic_inout:1;
+
+      /**
+       * If non-zero, then this variable may be packed along with other variables
+       * into a single varying slot, so this offset should be applied when
+       * accessing components.  For example, an offset of 1 means that the x
+       * component of this variable is actually stored in component y of the
+       * location specified by \c location.
+       */
+      unsigned location_frac:2;
+
+      /**
+       * Layout of the matrix.  Uses glsl_matrix_layout values.
+       */
+      unsigned matrix_layout:2;
+
+      /**
+       * Non-zero if this variable was created by lowering a named interface
+       * block which was not an array.
+       *
+       * Note that this variable and \c from_named_ifc_block_array will never
+       * both be non-zero.
+       */
+      unsigned from_named_ifc_block_nonarray:1;
+
+      /**
+       * Non-zero if this variable was created by lowering a named interface
+       * block which was an array.
+       *
+       * Note that this variable and \c from_named_ifc_block_nonarray will never
+       * both be non-zero.
+       */
+      unsigned from_named_ifc_block_array:1;
+
+      /**
+       * Non-zero if the variable must be a shader input. This is useful for
+       * constraints on function parameters.
+       */
+      unsigned must_be_shader_input:1;
+
+      /**
+       * Output index for dual source blending.
+       *
+       * \note
+       * The GLSL spec only allows the values 0 or 1 for the index in \b dual
+       * source blending.
+       */
+      unsigned index:1;
+
+      /**
+       * Precision qualifier.
+       *
+       * In desktop GLSL we do not care about precision qualifiers at all, in
+       * fact, the spec says that precision qualifiers are ignored.
+       *
+       * To make things easy, we make it so that this field is always
+       * GLSL_PRECISION_NONE on desktop shaders. This way all the variables
+       * have the same precision value and the checks we add in the compiler
+       * for this field will never break a desktop shader compile.
+       */
+      unsigned precision:2;
+
+      /**
+       * \brief Layout qualifier for gl_FragDepth.
+       *
+       * This is not equal to \c ir_depth_layout_none if and only if this
+       * variable is \c gl_FragDepth and a layout qualifier is specified.
+       */
+      ir_depth_layout depth_layout:3;
+
+      /**
+       * ARB_shader_image_load_store qualifiers.
+       */
+      unsigned image_read_only:1; /**< "readonly" qualifier. */
+      unsigned image_write_only:1; /**< "writeonly" qualifier. */
+      unsigned image_coherent:1;
+      unsigned image_volatile:1;
+      unsigned image_restrict:1;
+
+      /**
+       * ARB_shader_storage_buffer_object
+       */
+      unsigned from_ssbo_unsized_array:1; /**< unsized array buffer variable. */
+
+      /**
+       * Emit a warning if this variable is accessed.
+       */
+   private:
+      uint8_t warn_extension_index;
+
+   public:
+      /** Image internal format if specified explicitly, otherwise GL_NONE. */
+      uint16_t image_format;
+
+   private:
+      /**
+       * Number of state slots used
+       *
+       * \note
+       * This could be stored in as few as 7-bits, if necessary.  If it is made
+       * smaller, add an assertion to \c ir_variable::allocate_state_slots to
+       * be safe.
+       */
+      uint16_t _num_state_slots;
+
+   public:
+      /**
+       * Initial binding point for a sampler, atomic, or UBO.
+       *
+       * For array types, this represents the binding point for the first element.
+       */
+      int16_t binding;
+
+      /**
+       * Storage location of the base of this variable
+       *
+       * The precise meaning of this field depends on the nature of the variable.
+       *
+       *   - Vertex shader input: one of the values from \c gl_vert_attrib.
+       *   - Vertex shader output: one of the values from \c gl_varying_slot.
+       *   - Geometry shader input: one of the values from \c gl_varying_slot.
+       *   - Geometry shader output: one of the values from \c gl_varying_slot.
+       *   - Fragment shader input: one of the values from \c gl_varying_slot.
+       *   - Fragment shader output: one of the values from \c gl_frag_result.
+       *   - Uniforms: Per-stage uniform slot number for default uniform block.
+       *   - Uniforms: Index within the uniform block definition for UBO members.
+       *   - Non-UBO Uniforms: explicit location until linking then reused to
+       *     store uniform slot number.
+       *   - Other: This field is not currently used.
+       *
+       * If the variable is a uniform, shader input, or shader output, and the
+       * slot has not been assigned, the value will be -1.
+       */
+      int location;
+
+      /**
+       * Vertex stream output identifier.
+       */
+      unsigned stream;
+
+      /**
+       * Location an atomic counter is stored at.
+       */
+      unsigned offset;
+
+      /**
+       * Highest element accessed with a constant expression array index
+       *
+       * Not used for non-array variables.
+       */
+      unsigned max_array_access;
+
+      /**
+       * Allow (only) ir_variable direct access private members.
+       */
+      friend class ir_variable;
+   } data;
+
+   /**
+    * Value assigned in the initializer of a variable declared "const"
+    */
+   ir_constant *constant_value;
+
+   /**
+    * Constant expression assigned in the initializer of the variable
+    *
+    * \warning
+    * This field and \c ::constant_value are distinct.  Even if the two fields
+    * refer to constants with the same value, they must point to separate
+    * objects.
+    */
+   ir_constant *constant_initializer;
+
+private:
+   static const char *const warn_extension_table[];
+
+   union {
+      /**
+       * For variables which satisfy the is_interface_instance() predicate,
+       * this points to an array of integers such that if the ith member of
+       * the interface block is an array, max_ifc_array_access[i] is the
+       * maximum array element of that member that has been accessed.  If the
+       * ith member of the interface block is not an array,
+       * max_ifc_array_access[i] is unused.
+       *
+       * For variables whose type is not an interface block, this pointer is
+       * NULL.
+       */
+      unsigned *max_ifc_array_access;
+
+      /**
+       * Built-in state that backs this uniform
+       *
+       * Once set at variable creation, \c state_slots must remain invariant.
+       *
+       * If the variable is not a uniform, \c _num_state_slots will be zero
+       * and \c state_slots will be \c NULL.
+       */
+      ir_state_slot *state_slots;
+   } u;
+
+   /**
+    * For variables that are in an interface block or are an instance of an
+    * interface block, this is the \c GLSL_TYPE_INTERFACE type for that block.
+    *
+    * \sa ir_variable::location
+    */
+   const glsl_type *interface_type;
+
+   /**
+    * Name used for anonymous compiler temporaries
+    */
+   static const char tmp_name[];
+
+public:
+   /**
+    * Should the construct keep names for ir_var_temporary variables?
+    *
+    * When this global is false, names passed to the constructor for
+    * \c ir_var_temporary variables will be dropped.  Instead, the variable will
+    * be named "compiler_temp".  This name will be in static storage.
+    *
+    * \warning
+    * \b NEVER change the mode of an \c ir_var_temporary.
+    *
+    * \warning
+    * This variable is \b not thread-safe.  It is global, \b not
+    * per-context. It begins life false.  A context can, at some point, make
+    * it true.  From that point on, it will be true forever.  This should be
+    * okay since it will only be set true while debugging.
+    */
+   static bool temporaries_allocate_names;
+};
+
+/**
+ * A function that returns whether a built-in function is available in the
+ * current shading language (based on version, ES or desktop, and extensions).
+ */
+typedef bool (*builtin_available_predicate)(const _mesa_glsl_parse_state *);
+
+/*@{*/
+/**
+ * The representation of a function instance; may be the full definition or
+ * simply a prototype.
+ */
+class ir_function_signature : public ir_instruction {
+   /* An ir_function_signature will be part of the list of signatures in
+    * an ir_function.
+    */
+public:
+   ir_function_signature(const glsl_type *return_type,
+                         builtin_available_predicate builtin_avail = NULL);
+
+   virtual ir_function_signature *clone(void *mem_ctx,
+					struct hash_table *ht) const;
+   ir_function_signature *clone_prototype(void *mem_ctx,
+					  struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   /**
+    * Attempt to evaluate this function as a constant expression,
+    * given a list of the actual parameters and the variable context.
+    * Returns NULL for non-built-ins.
+    */
+   ir_constant *constant_expression_value(exec_list *actual_parameters, struct hash_table *variable_context);
+
+   /**
+    * Get the name of the function for which this is a signature
+    */
+   const char *function_name() const;
+
+   /**
+    * Get a handle to the function for which this is a signature
+    *
+    * There is no setter function, this function returns a \c const pointer,
+    * and \c ir_function_signature::_function is private for a reason.  The
+    * only way to make a connection between a function and function signature
+    * is via \c ir_function::add_signature.  This helps ensure that certain
+    * invariants (i.e., a function signature is in the list of signatures for
+    * its \c _function) are met.
+    *
+    * \sa ir_function::add_signature
+    */
+   inline const class ir_function *function() const
+   {
+      return this->_function;
+   }
+
+   /**
+    * Check whether the qualifiers match between this signature's parameters
+    * and the supplied parameter list.  If not, returns the name of the first
+    * parameter with mismatched qualifiers (for use in error messages).
+    */
+   const char *qualifiers_match(exec_list *params);
+
+   /**
+    * Replace the current parameter list with the given one.  This is useful
+    * if the current information came from a prototype, and either has invalid
+    * or missing parameter names.
+    */
+   void replace_parameters(exec_list *new_params);
+
+   /**
+    * Function return type.
+    *
+    * \note This discards the optional precision qualifier.
+    */
+   const struct glsl_type *return_type;
+
+   /**
+    * List of ir_variable of function parameters.
+    *
+    * This represents the storage.  The paramaters passed in a particular
+    * call will be in ir_call::actual_paramaters.
+    */
+   struct exec_list parameters;
+
+   /** Whether or not this function has a body (which may be empty). */
+   unsigned is_defined:1;
+
+   /** Whether or not this function signature is a built-in. */
+   bool is_builtin() const;
+
+   /**
+    * Whether or not this function is an intrinsic to be implemented
+    * by the driver.
+    */
+   bool is_intrinsic;
+
+   /** Whether or not a built-in is available for this shader. */
+   bool is_builtin_available(const _mesa_glsl_parse_state *state) const;
+
+   /** Body of instructions in the function. */
+   struct exec_list body;
+
+private:
+   /**
+    * A function pointer to a predicate that answers whether a built-in
+    * function is available in the current shader.  NULL if not a built-in.
+    */
+   builtin_available_predicate builtin_avail;
+
+   /** Function of which this signature is one overload. */
+   class ir_function *_function;
+
+   /** Function signature of which this one is a prototype clone */
+   const ir_function_signature *origin;
+
+   friend class ir_function;
+
+   /**
+    * Helper function to run a list of instructions for constant
+    * expression evaluation.
+    *
+    * The hash table represents the values of the visible variables.
+    * There are no scoping issues because the table is indexed on
+    * ir_variable pointers, not variable names.
+    *
+    * Returns false if the expression is not constant, true otherwise,
+    * and the value in *result if result is non-NULL.
+    */
+   bool constant_expression_evaluate_expression_list(const struct exec_list &body,
+						     struct hash_table *variable_context,
+						     ir_constant **result);
+};
+
+
+/**
+ * Header for tracking multiple overloaded functions with the same name.
+ * Contains a list of ir_function_signatures representing each of the
+ * actual functions.
+ */
+class ir_function : public ir_instruction {
+public:
+   ir_function(const char *name);
+
+   virtual ir_function *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   void add_signature(ir_function_signature *sig)
+   {
+      sig->_function = this;
+      this->signatures.push_tail(sig);
+   }
+
+   /**
+    * Find a signature that matches a set of actual parameters, taking implicit
+    * conversions into account.  Also flags whether the match was exact.
+    */
+   ir_function_signature *matching_signature(_mesa_glsl_parse_state *state,
+                                             const exec_list *actual_param,
+                                             bool allow_builtins,
+					     bool *match_is_exact);
+
+   /**
+    * Find a signature that matches a set of actual parameters, taking implicit
+    * conversions into account.
+    */
+   ir_function_signature *matching_signature(_mesa_glsl_parse_state *state,
+                                             const exec_list *actual_param,
+                                             bool allow_builtins);
+
+   /**
+    * Find a signature that exactly matches a set of actual parameters without
+    * any implicit type conversions.
+    */
+   ir_function_signature *exact_matching_signature(_mesa_glsl_parse_state *state,
+                                                   const exec_list *actual_ps);
+
+   /**
+    * Name of the function.
+    */
+   const char *name;
+
+   /** Whether or not this function has a signature that isn't a built-in. */
+   bool has_user_signature();
+
+   /**
+    * List of ir_function_signature for each overloaded function with this name.
+    */
+   struct exec_list signatures;
+
+   /**
+    * is this function a subroutine type declaration
+    * e.g. subroutine void type1(float arg1);
+    */
+   bool is_subroutine;
+
+   /**
+    * is this function associated to a subroutine type
+    * e.g. subroutine (type1, type2) function_name { function_body };
+    * would have num_subroutine_types 2,
+    * and pointers to the type1 and type2 types.
+    */
+   int num_subroutine_types;
+   const struct glsl_type **subroutine_types;
+
+   int subroutine_index;
+};
+
+inline const char *ir_function_signature::function_name() const
+{
+   return this->_function->name;
+}
+/*@}*/
+
+
+/**
+ * IR instruction representing high-level if-statements
+ */
+class ir_if : public ir_instruction {
+public:
+   ir_if(ir_rvalue *condition)
+      : ir_instruction(ir_type_if), condition(condition)
+   {
+   }
+
+   virtual ir_if *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   ir_rvalue *condition;
+   /** List of ir_instruction for the body of the then branch */
+   exec_list  then_instructions;
+   /** List of ir_instruction for the body of the else branch */
+   exec_list  else_instructions;
+};
+
+
+/**
+ * IR instruction representing a high-level loop structure.
+ */
+class ir_loop : public ir_instruction {
+public:
+   ir_loop();
+
+   virtual ir_loop *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   /** List of ir_instruction that make up the body of the loop. */
+   exec_list body_instructions;
+};
+
+
+class ir_assignment : public ir_instruction {
+public:
+   ir_assignment(ir_rvalue *lhs, ir_rvalue *rhs, ir_rvalue *condition = NULL);
+
+   /**
+    * Construct an assignment with an explicit write mask
+    *
+    * \note
+    * Since a write mask is supplied, the LHS must already be a bare
+    * \c ir_dereference.  The cannot be any swizzles in the LHS.
+    */
+   ir_assignment(ir_dereference *lhs, ir_rvalue *rhs, ir_rvalue *condition,
+		 unsigned write_mask);
+
+   virtual ir_assignment *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   /**
+    * Get a whole variable written by an assignment
+    *
+    * If the LHS of the assignment writes a whole variable, the variable is
+    * returned.  Otherwise \c NULL is returned.  Examples of whole-variable
+    * assignment are:
+    *
+    *  - Assigning to a scalar
+    *  - Assigning to all components of a vector
+    *  - Whole array (or matrix) assignment
+    *  - Whole structure assignment
+    */
+   ir_variable *whole_variable_written();
+
+   /**
+    * Set the LHS of an assignment
+    */
+   void set_lhs(ir_rvalue *lhs);
+
+   /**
+    * Left-hand side of the assignment.
+    *
+    * This should be treated as read only.  If you need to set the LHS of an
+    * assignment, use \c ir_assignment::set_lhs.
+    */
+   ir_dereference *lhs;
+
+   /**
+    * Value being assigned
+    */
+   ir_rvalue *rhs;
+
+   /**
+    * Optional condition for the assignment.
+    */
+   ir_rvalue *condition;
+
+
+   /**
+    * Component mask written
+    *
+    * For non-vector types in the LHS, this field will be zero.  For vector
+    * types, a bit will be set for each component that is written.  Note that
+    * for \c vec2 and \c vec3 types only the lower bits will ever be set.
+    *
+    * A partially-set write mask means that each enabled channel gets
+    * the value from a consecutive channel of the rhs.  For example,
+    * to write just .xyw of gl_FrontColor with color:
+    *
+    * (assign (constant bool (1)) (xyw)
+    *     (var_ref gl_FragColor)
+    *     (swiz xyw (var_ref color)))
+    */
+   unsigned write_mask:4;
+};
+
+/* Update ir_expression::get_num_operands() and operator_strs when
+ * updating this list.
+ */
+enum ir_expression_operation {
+   ir_unop_bit_not,
+   ir_unop_logic_not,
+   ir_unop_neg,
+   ir_unop_abs,
+   ir_unop_sign,
+   ir_unop_rcp,
+   ir_unop_rsq,
+   ir_unop_sqrt,
+   ir_unop_exp,         /**< Log base e on gentype */
+   ir_unop_log,	        /**< Natural log on gentype */
+   ir_unop_exp2,
+   ir_unop_log2,
+   ir_unop_f2i,         /**< Float-to-integer conversion. */
+   ir_unop_f2u,         /**< Float-to-unsigned conversion. */
+   ir_unop_i2f,         /**< Integer-to-float conversion. */
+   ir_unop_f2b,         /**< Float-to-boolean conversion */
+   ir_unop_b2f,         /**< Boolean-to-float conversion */
+   ir_unop_i2b,         /**< int-to-boolean conversion */
+   ir_unop_b2i,         /**< Boolean-to-int conversion */
+   ir_unop_u2f,         /**< Unsigned-to-float conversion. */
+   ir_unop_i2u,         /**< Integer-to-unsigned conversion. */
+   ir_unop_u2i,         /**< Unsigned-to-integer conversion. */
+   ir_unop_d2f,         /**< Double-to-float conversion. */
+   ir_unop_f2d,         /**< Float-to-double conversion. */
+   ir_unop_d2i,         /**< Double-to-integer conversion. */
+   ir_unop_i2d,         /**< Integer-to-double conversion. */
+   ir_unop_d2u,         /**< Double-to-unsigned conversion. */
+   ir_unop_u2d,         /**< Unsigned-to-double conversion. */
+   ir_unop_d2b,         /**< Double-to-boolean conversion. */
+   ir_unop_bitcast_i2f, /**< Bit-identical int-to-float "conversion" */
+   ir_unop_bitcast_f2i, /**< Bit-identical float-to-int "conversion" */
+   ir_unop_bitcast_u2f, /**< Bit-identical uint-to-float "conversion" */
+   ir_unop_bitcast_f2u, /**< Bit-identical float-to-uint "conversion" */
+
+   /**
+    * \name Unary floating-point rounding operations.
+    */
+   /*@{*/
+   ir_unop_trunc,
+   ir_unop_ceil,
+   ir_unop_floor,
+   ir_unop_fract,
+   ir_unop_round_even,
+   /*@}*/
+
+   /**
+    * \name Trigonometric operations.
+    */
+   /*@{*/
+   ir_unop_sin,
+   ir_unop_cos,
+   /*@}*/
+
+   /**
+    * \name Partial derivatives.
+    */
+   /*@{*/
+   ir_unop_dFdx,
+   ir_unop_dFdx_coarse,
+   ir_unop_dFdx_fine,
+   ir_unop_dFdy,
+   ir_unop_dFdy_coarse,
+   ir_unop_dFdy_fine,
+   /*@}*/
+
+   /**
+    * \name Floating point pack and unpack operations.
+    */
+   /*@{*/
+   ir_unop_pack_snorm_2x16,
+   ir_unop_pack_snorm_4x8,
+   ir_unop_pack_unorm_2x16,
+   ir_unop_pack_unorm_4x8,
+   ir_unop_pack_half_2x16,
+   ir_unop_unpack_snorm_2x16,
+   ir_unop_unpack_snorm_4x8,
+   ir_unop_unpack_unorm_2x16,
+   ir_unop_unpack_unorm_4x8,
+   ir_unop_unpack_half_2x16,
+   /*@}*/
+
+   /**
+    * \name Lowered floating point unpacking operations.
+    *
+    * \see lower_packing_builtins_visitor::split_unpack_half_2x16
+    */
+   /*@{*/
+   ir_unop_unpack_half_2x16_split_x,
+   ir_unop_unpack_half_2x16_split_y,
+   /*@}*/
+
+   /**
+    * \name Bit operations, part of ARB_gpu_shader5.
+    */
+   /*@{*/
+   ir_unop_bitfield_reverse,
+   ir_unop_bit_count,
+   ir_unop_find_msb,
+   ir_unop_find_lsb,
+   /*@}*/
+
+   ir_unop_saturate,
+
+   /**
+    * \name Double packing, part of ARB_gpu_shader_fp64.
+    */
+   /*@{*/
+   ir_unop_pack_double_2x32,
+   ir_unop_unpack_double_2x32,
+   /*@}*/
+
+   ir_unop_frexp_sig,
+   ir_unop_frexp_exp,
+
+   ir_unop_noise,
+
+   ir_unop_subroutine_to_int,
+   /**
+    * Interpolate fs input at centroid
+    *
+    * operand0 is the fs input.
+    */
+   ir_unop_interpolate_at_centroid,
+
+   /**
+    * Ask the driver for the total size of a buffer block.
+    *
+    * operand0 is the ir_constant buffer block index in the linked shader.
+    */
+   ir_unop_get_buffer_size,
+
+   /**
+    * Calculate length of an unsized array inside a buffer block.
+    * This opcode is going to be replaced in a lowering pass inside
+    * the linker.
+    *
+    * operand0 is the unsized array's ir_value for the calculation
+    * of its length.
+    */
+   ir_unop_ssbo_unsized_array_length,
+
+   /**
+    * A sentinel marking the last of the unary operations.
+    */
+   ir_last_unop = ir_unop_ssbo_unsized_array_length,
+
+   ir_binop_add,
+   ir_binop_sub,
+   ir_binop_mul,       /**< Floating-point or low 32-bit integer multiply. */
+   ir_binop_imul_high, /**< Calculates the high 32-bits of a 64-bit multiply. */
+   ir_binop_div,
+
+   /**
+    * Returns the carry resulting from the addition of the two arguments.
+    */
+   /*@{*/
+   ir_binop_carry,
+   /*@}*/
+
+   /**
+    * Returns the borrow resulting from the subtraction of the second argument
+    * from the first argument.
+    */
+   /*@{*/
+   ir_binop_borrow,
+   /*@}*/
+
+   /**
+    * Takes one of two combinations of arguments:
+    *
+    * - mod(vecN, vecN)
+    * - mod(vecN, float)
+    *
+    * Does not take integer types.
+    */
+   ir_binop_mod,
+
+   /**
+    * \name Binary comparison operators which return a boolean vector.
+    * The type of both operands must be equal.
+    */
+   /*@{*/
+   ir_binop_less,
+   ir_binop_greater,
+   ir_binop_lequal,
+   ir_binop_gequal,
+   ir_binop_equal,
+   ir_binop_nequal,
+   /**
+    * Returns single boolean for whether all components of operands[0]
+    * equal the components of operands[1].
+    */
+   ir_binop_all_equal,
+   /**
+    * Returns single boolean for whether any component of operands[0]
+    * is not equal to the corresponding component of operands[1].
+    */
+   ir_binop_any_nequal,
+   /*@}*/
+
+   /**
+    * \name Bit-wise binary operations.
+    */
+   /*@{*/
+   ir_binop_lshift,
+   ir_binop_rshift,
+   ir_binop_bit_and,
+   ir_binop_bit_xor,
+   ir_binop_bit_or,
+   /*@}*/
+
+   ir_binop_logic_and,
+   ir_binop_logic_xor,
+   ir_binop_logic_or,
+
+   ir_binop_dot,
+   ir_binop_min,
+   ir_binop_max,
+
+   ir_binop_pow,
+
+   /**
+    * \name Lowered floating point packing operations.
+    *
+    * \see lower_packing_builtins_visitor::split_pack_half_2x16
+    */
+   /*@{*/
+   ir_binop_pack_half_2x16_split,
+   /*@}*/
+
+   /**
+    * Load a value the size of a given GLSL type from a uniform block.
+    *
+    * operand0 is the ir_constant uniform block index in the linked shader.
+    * operand1 is a byte offset within the uniform block.
+    */
+   ir_binop_ubo_load,
+
+   /**
+    * \name Multiplies a number by two to a power, part of ARB_gpu_shader5.
+    */
+   /*@{*/
+   ir_binop_ldexp,
+   /*@}*/
+
+   /**
+    * Extract a scalar from a vector
+    *
+    * operand0 is the vector
+    * operand1 is the index of the field to read from operand0
+    */
+   ir_binop_vector_extract,
+
+   /**
+    * Interpolate fs input at offset
+    *
+    * operand0 is the fs input
+    * operand1 is the offset from the pixel center
+    */
+   ir_binop_interpolate_at_offset,
+
+   /**
+    * Interpolate fs input at sample position
+    *
+    * operand0 is the fs input
+    * operand1 is the sample ID
+    */
+   ir_binop_interpolate_at_sample,
+
+   /**
+    * A sentinel marking the last of the binary operations.
+    */
+   ir_last_binop = ir_binop_interpolate_at_sample,
+
+   /**
+    * \name Fused floating-point multiply-add, part of ARB_gpu_shader5.
+    */
+   /*@{*/
+   ir_triop_fma,
+   /*@}*/
+
+   ir_triop_lrp,
+
+   /**
+    * \name Conditional Select
+    *
+    * A vector conditional select instruction (like ?:, but operating per-
+    * component on vectors).
+    *
+    * \see lower_instructions_visitor::ldexp_to_arith
+    */
+   /*@{*/
+   ir_triop_csel,
+   /*@}*/
+
+   ir_triop_bitfield_extract,
+
+   /**
+    * Generate a value with one field of a vector changed
+    *
+    * operand0 is the vector
+    * operand1 is the value to write into the vector result
+    * operand2 is the index in operand0 to be modified
+    */
+   ir_triop_vector_insert,
+
+   /**
+    * A sentinel marking the last of the ternary operations.
+    */
+   ir_last_triop = ir_triop_vector_insert,
+
+   ir_quadop_bitfield_insert,
+
+   ir_quadop_vector,
+
+   /**
+    * A sentinel marking the last of the ternary operations.
+    */
+   ir_last_quadop = ir_quadop_vector,
+
+   /**
+    * A sentinel marking the last of all operations.
+    */
+   ir_last_opcode = ir_quadop_vector
+};
+
+class ir_expression : public ir_rvalue {
+public:
+   ir_expression(int op, const struct glsl_type *type,
+                 ir_rvalue *op0, ir_rvalue *op1 = NULL,
+                 ir_rvalue *op2 = NULL, ir_rvalue *op3 = NULL);
+
+   /**
+    * Constructor for unary operation expressions
+    */
+   ir_expression(int op, ir_rvalue *);
+
+   /**
+    * Constructor for binary operation expressions
+    */
+   ir_expression(int op, ir_rvalue *op0, ir_rvalue *op1);
+
+   /**
+    * Constructor for ternary operation expressions
+    */
+   ir_expression(int op, ir_rvalue *op0, ir_rvalue *op1, ir_rvalue *op2);
+
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+   virtual ir_expression *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   /**
+    * Attempt to constant-fold the expression
+    *
+    * The "variable_context" hash table links ir_variable * to ir_constant *
+    * that represent the variables' values.  \c NULL represents an empty
+    * context.
+    *
+    * If the expression cannot be constant folded, this method will return
+    * \c NULL.
+    */
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   /**
+    * Determine the number of operands used by an expression
+    */
+   static unsigned int get_num_operands(ir_expression_operation);
+
+   /**
+    * Determine the number of operands used by an expression
+    */
+   unsigned int get_num_operands() const
+   {
+      return (this->operation == ir_quadop_vector)
+	 ? this->type->vector_elements : get_num_operands(operation);
+   }
+
+   /**
+    * Return whether the expression operates on vectors horizontally.
+    */
+   bool is_horizontal() const
+   {
+      return operation == ir_binop_all_equal ||
+             operation == ir_binop_any_nequal ||
+             operation == ir_binop_dot ||
+             operation == ir_binop_vector_extract ||
+             operation == ir_triop_vector_insert ||
+             operation == ir_quadop_vector;
+   }
+
+   /**
+    * Return a string representing this expression's operator.
+    */
+   const char *operator_string();
+
+   /**
+    * Return a string representing this expression's operator.
+    */
+   static const char *operator_string(ir_expression_operation);
+
+
+   /**
+    * Do a reverse-lookup to translate the given string into an operator.
+    */
+   static ir_expression_operation get_operator(const char *);
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   virtual ir_variable *variable_referenced() const;
+
+   ir_expression_operation operation;
+   ir_rvalue *operands[4];
+};
+
+
+/**
+ * HIR instruction representing a high-level function call, containing a list
+ * of parameters and returning a value in the supplied temporary.
+ */
+class ir_call : public ir_instruction {
+public:
+   ir_call(ir_function_signature *callee,
+	   ir_dereference_variable *return_deref,
+	   exec_list *actual_parameters)
+      : ir_instruction(ir_type_call), return_deref(return_deref), callee(callee), sub_var(NULL), array_idx(NULL)
+   {
+      assert(callee->return_type != NULL);
+      actual_parameters->move_nodes_to(& this->actual_parameters);
+      this->use_builtin = callee->is_builtin();
+   }
+
+   ir_call(ir_function_signature *callee,
+	   ir_dereference_variable *return_deref,
+	   exec_list *actual_parameters,
+	   ir_variable *var, ir_rvalue *array_idx)
+      : ir_instruction(ir_type_call), return_deref(return_deref), callee(callee), sub_var(var), array_idx(array_idx)
+   {
+      assert(callee->return_type != NULL);
+      actual_parameters->move_nodes_to(& this->actual_parameters);
+      this->use_builtin = callee->is_builtin();
+   }
+
+   virtual ir_call *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   /**
+    * Get the name of the function being called.
+    */
+   const char *callee_name() const
+   {
+      return callee->function_name();
+   }
+
+   /**
+    * Generates an inline version of the function before @ir,
+    * storing the return value in return_deref.
+    */
+   void generate_inline(ir_instruction *ir);
+
+   /**
+    * Storage for the function's return value.
+    * This must be NULL if the return type is void.
+    */
+   ir_dereference_variable *return_deref;
+
+   /**
+    * The specific function signature being called.
+    */
+   ir_function_signature *callee;
+
+   /* List of ir_rvalue of paramaters passed in this call. */
+   exec_list actual_parameters;
+
+   /** Should this call only bind to a built-in function? */
+   bool use_builtin;
+
+   /*
+    * ARB_shader_subroutine support -
+    * the subroutine uniform variable and array index
+    * rvalue to be used in the lowering pass later.
+    */
+   ir_variable *sub_var;
+   ir_rvalue *array_idx;
+};
+
+
+/**
+ * \name Jump-like IR instructions.
+ *
+ * These include \c break, \c continue, \c return, and \c discard.
+ */
+/*@{*/
+class ir_jump : public ir_instruction {
+protected:
+   ir_jump(enum ir_node_type t)
+      : ir_instruction(t)
+   {
+   }
+};
+
+class ir_return : public ir_jump {
+public:
+   ir_return()
+      : ir_jump(ir_type_return), value(NULL)
+   {
+   }
+
+   ir_return(ir_rvalue *value)
+      : ir_jump(ir_type_return), value(value)
+   {
+   }
+
+   virtual ir_return *clone(void *mem_ctx, struct hash_table *) const;
+
+   ir_rvalue *get_value() const
+   {
+      return value;
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   ir_rvalue *value;
+};
+
+
+/**
+ * Jump instructions used inside loops
+ *
+ * These include \c break and \c continue.  The \c break within a loop is
+ * different from the \c break within a switch-statement.
+ *
+ * \sa ir_switch_jump
+ */
+class ir_loop_jump : public ir_jump {
+public:
+   enum jump_mode {
+      jump_break,
+      jump_continue
+   };
+
+   ir_loop_jump(jump_mode mode)
+      : ir_jump(ir_type_loop_jump)
+   {
+      this->mode = mode;
+   }
+
+   virtual ir_loop_jump *clone(void *mem_ctx, struct hash_table *) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   bool is_break() const
+   {
+      return mode == jump_break;
+   }
+
+   bool is_continue() const
+   {
+      return mode == jump_continue;
+   }
+
+   /** Mode selector for the jump instruction. */
+   enum jump_mode mode;
+};
+
+/**
+ * IR instruction representing discard statements.
+ */
+class ir_discard : public ir_jump {
+public:
+   ir_discard()
+      : ir_jump(ir_type_discard)
+   {
+      this->condition = NULL;
+   }
+
+   ir_discard(ir_rvalue *cond)
+      : ir_jump(ir_type_discard)
+   {
+      this->condition = cond;
+   }
+
+   virtual ir_discard *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   ir_rvalue *condition;
+};
+/*@}*/
+
+
+/**
+ * Texture sampling opcodes used in ir_texture
+ */
+enum ir_texture_opcode {
+   ir_tex,		/**< Regular texture look-up */
+   ir_txb,		/**< Texture look-up with LOD bias */
+   ir_txl,		/**< Texture look-up with explicit LOD */
+   ir_txd,		/**< Texture look-up with partial derivatvies */
+   ir_txf,		/**< Texel fetch with explicit LOD */
+   ir_txf_ms,           /**< Multisample texture fetch */
+   ir_txs,		/**< Texture size */
+   ir_lod,		/**< Texture lod query */
+   ir_tg4,		/**< Texture gather */
+   ir_query_levels,     /**< Texture levels query */
+   ir_texture_samples,  /**< Texture samples query */
+   ir_samples_identical, /**< Query whether all samples are definitely identical. */
+};
+
+
+/**
+ * IR instruction to sample a texture
+ *
+ * The specific form of the IR instruction depends on the \c mode value
+ * selected from \c ir_texture_opcodes.  In the printed IR, these will
+ * appear as:
+ *
+ *                                    Texel offset (0 or an expression)
+ *                                    | Projection divisor
+ *                                    | |  Shadow comparitor
+ *                                    | |  |
+ *                                    v v  v
+ * (tex <type> <sampler> <coordinate> 0 1 ( ))
+ * (txb <type> <sampler> <coordinate> 0 1 ( ) <bias>)
+ * (txl <type> <sampler> <coordinate> 0 1 ( ) <lod>)
+ * (txd <type> <sampler> <coordinate> 0 1 ( ) (dPdx dPdy))
+ * (txf <type> <sampler> <coordinate> 0       <lod>)
+ * (txf_ms
+ *      <type> <sampler> <coordinate>         <sample_index>)
+ * (txs <type> <sampler> <lod>)
+ * (lod <type> <sampler> <coordinate>)
+ * (tg4 <type> <sampler> <coordinate> <offset> <component>)
+ * (query_levels <type> <sampler>)
+ * (samples_identical <sampler> <coordinate>)
+ */
+class ir_texture : public ir_rvalue {
+public:
+   ir_texture(enum ir_texture_opcode op)
+      : ir_rvalue(ir_type_texture),
+        op(op), sampler(NULL), coordinate(NULL), projector(NULL),
+        shadow_comparitor(NULL), offset(NULL)
+   {
+      memset(&lod_info, 0, sizeof(lod_info));
+   }
+
+   virtual ir_texture *clone(void *mem_ctx, struct hash_table *) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+   /**
+    * Return a string representing the ir_texture_opcode.
+    */
+   const char *opcode_string();
+
+   /** Set the sampler and type. */
+   void set_sampler(ir_dereference *sampler, const glsl_type *type);
+
+   /**
+    * Do a reverse-lookup to translate a string into an ir_texture_opcode.
+    */
+   static ir_texture_opcode get_opcode(const char *);
+
+   enum ir_texture_opcode op;
+
+   /** Sampler to use for the texture access. */
+   ir_dereference *sampler;
+
+   /** Texture coordinate to sample */
+   ir_rvalue *coordinate;
+
+   /**
+    * Value used for projective divide.
+    *
+    * If there is no projective divide (the common case), this will be
+    * \c NULL.  Optimization passes should check for this to point to a constant
+    * of 1.0 and replace that with \c NULL.
+    */
+   ir_rvalue *projector;
+
+   /**
+    * Coordinate used for comparison on shadow look-ups.
+    *
+    * If there is no shadow comparison, this will be \c NULL.  For the
+    * \c ir_txf opcode, this *must* be \c NULL.
+    */
+   ir_rvalue *shadow_comparitor;
+
+   /** Texel offset. */
+   ir_rvalue *offset;
+
+   union {
+      ir_rvalue *lod;		/**< Floating point LOD */
+      ir_rvalue *bias;		/**< Floating point LOD bias */
+      ir_rvalue *sample_index;  /**< MSAA sample index */
+      ir_rvalue *component;     /**< Gather component selector */
+      struct {
+	 ir_rvalue *dPdx;	/**< Partial derivative of coordinate wrt X */
+	 ir_rvalue *dPdy;	/**< Partial derivative of coordinate wrt Y */
+      } grad;
+   } lod_info;
+};
+
+
+struct ir_swizzle_mask {
+   unsigned x:2;
+   unsigned y:2;
+   unsigned z:2;
+   unsigned w:2;
+
+   /**
+    * Number of components in the swizzle.
+    */
+   unsigned num_components:3;
+
+   /**
+    * Does the swizzle contain duplicate components?
+    *
+    * L-value swizzles cannot contain duplicate components.
+    */
+   unsigned has_duplicates:1;
+};
+
+
+class ir_swizzle : public ir_rvalue {
+public:
+   ir_swizzle(ir_rvalue *, unsigned x, unsigned y, unsigned z, unsigned w,
+              unsigned count);
+
+   ir_swizzle(ir_rvalue *val, const unsigned *components, unsigned count);
+
+   ir_swizzle(ir_rvalue *val, ir_swizzle_mask mask);
+
+   virtual ir_swizzle *clone(void *mem_ctx, struct hash_table *) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   /**
+    * Construct an ir_swizzle from the textual representation.  Can fail.
+    */
+   static ir_swizzle *create(ir_rvalue *, const char *, unsigned vector_length);
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+   bool is_lvalue() const
+   {
+      return val->is_lvalue() && !mask.has_duplicates;
+   }
+
+   /**
+    * Get the variable that is ultimately referenced by an r-value
+    */
+   virtual ir_variable *variable_referenced() const;
+
+   ir_rvalue *val;
+   ir_swizzle_mask mask;
+
+private:
+   /**
+    * Initialize the mask component of a swizzle
+    *
+    * This is used by the \c ir_swizzle constructors.
+    */
+   void init_mask(const unsigned *components, unsigned count);
+};
+
+
+class ir_dereference : public ir_rvalue {
+public:
+   virtual ir_dereference *clone(void *mem_ctx, struct hash_table *) const = 0;
+
+   bool is_lvalue() const;
+
+   /**
+    * Get the variable that is ultimately referenced by an r-value
+    */
+   virtual ir_variable *variable_referenced() const = 0;
+
+protected:
+   ir_dereference(enum ir_node_type t)
+      : ir_rvalue(t)
+   {
+   }
+};
+
+
+class ir_dereference_variable : public ir_dereference {
+public:
+   ir_dereference_variable(ir_variable *var);
+
+   virtual ir_dereference_variable *clone(void *mem_ctx,
+					  struct hash_table *) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+   /**
+    * Get the variable that is ultimately referenced by an r-value
+    */
+   virtual ir_variable *variable_referenced() const
+   {
+      return this->var;
+   }
+
+   virtual ir_variable *whole_variable_referenced()
+   {
+      /* ir_dereference_variable objects always dereference the entire
+       * variable.  However, if this dereference is dereferenced by anything
+       * else, the complete deferefernce chain is not a whole-variable
+       * dereference.  This method should only be called on the top most
+       * ir_rvalue in a dereference chain.
+       */
+      return this->var;
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   /**
+    * Object being dereferenced.
+    */
+   ir_variable *var;
+};
+
+
+class ir_dereference_array : public ir_dereference {
+public:
+   ir_dereference_array(ir_rvalue *value, ir_rvalue *array_index);
+
+   ir_dereference_array(ir_variable *var, ir_rvalue *array_index);
+
+   virtual ir_dereference_array *clone(void *mem_ctx,
+				       struct hash_table *) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+   /**
+    * Get the variable that is ultimately referenced by an r-value
+    */
+   virtual ir_variable *variable_referenced() const
+   {
+      return this->array->variable_referenced();
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   ir_rvalue *array;
+   ir_rvalue *array_index;
+
+private:
+   void set_array(ir_rvalue *value);
+};
+
+
+class ir_dereference_record : public ir_dereference {
+public:
+   ir_dereference_record(ir_rvalue *value, const char *field);
+
+   ir_dereference_record(ir_variable *var, const char *field);
+
+   virtual ir_dereference_record *clone(void *mem_ctx,
+					struct hash_table *) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   /**
+    * Get the variable that is ultimately referenced by an r-value
+    */
+   virtual ir_variable *variable_referenced() const
+   {
+      return this->record->variable_referenced();
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   ir_rvalue *record;
+   const char *field;
+};
+
+
+/**
+ * Data stored in an ir_constant
+ */
+union ir_constant_data {
+      unsigned u[16];
+      int i[16];
+      float f[16];
+      bool b[16];
+      double d[16];
+};
+
+
+class ir_constant : public ir_rvalue {
+public:
+   ir_constant(const struct glsl_type *type, const ir_constant_data *data);
+   ir_constant(bool b, unsigned vector_elements=1);
+   ir_constant(unsigned int u, unsigned vector_elements=1);
+   ir_constant(int i, unsigned vector_elements=1);
+   ir_constant(float f, unsigned vector_elements=1);
+   ir_constant(double d, unsigned vector_elements=1);
+
+   /**
+    * Construct an ir_constant from a list of ir_constant values
+    */
+   ir_constant(const struct glsl_type *type, exec_list *values);
+
+   /**
+    * Construct an ir_constant from a scalar component of another ir_constant
+    *
+    * The new \c ir_constant inherits the type of the component from the
+    * source constant.
+    *
+    * \note
+    * In the case of a matrix constant, the new constant is a scalar, \b not
+    * a vector.
+    */
+   ir_constant(const ir_constant *c, unsigned i);
+
+   /**
+    * Return a new ir_constant of the specified type containing all zeros.
+    */
+   static ir_constant *zero(void *mem_ctx, const glsl_type *type);
+
+   virtual ir_constant *clone(void *mem_ctx, struct hash_table *) const;
+
+   virtual ir_constant *constant_expression_value(struct hash_table *variable_context = NULL);
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   virtual bool equals(const ir_instruction *ir,
+                       enum ir_node_type ignore = ir_type_unset) const;
+
+   /**
+    * Get a particular component of a constant as a specific type
+    *
+    * This is useful, for example, to get a value from an integer constant
+    * as a float or bool.  This appears frequently when constructors are
+    * called with all constant parameters.
+    */
+   /*@{*/
+   bool get_bool_component(unsigned i) const;
+   float get_float_component(unsigned i) const;
+   double get_double_component(unsigned i) const;
+   int get_int_component(unsigned i) const;
+   unsigned get_uint_component(unsigned i) const;
+   /*@}*/
+
+   ir_constant *get_array_element(unsigned i) const;
+
+   ir_constant *get_record_field(const char *name);
+
+   /**
+    * Copy the values on another constant at a given offset.
+    *
+    * The offset is ignored for array or struct copies, it's only for
+    * scalars or vectors into vectors or matrices.
+    *
+    * With identical types on both sides and zero offset it's clone()
+    * without creating a new object.
+    */
+
+   void copy_offset(ir_constant *src, int offset);
+
+   /**
+    * Copy the values on another constant at a given offset and
+    * following an assign-like mask.
+    *
+    * The mask is ignored for scalars.
+    *
+    * Note that this function only handles what assign can handle,
+    * i.e. at most a vector as source and a column of a matrix as
+    * destination.
+    */
+
+   void copy_masked_offset(ir_constant *src, int offset, unsigned int mask);
+
+   /**
+    * Determine whether a constant has the same value as another constant
+    *
+    * \sa ir_constant::is_zero, ir_constant::is_one,
+    * ir_constant::is_negative_one
+    */
+   bool has_value(const ir_constant *) const;
+
+   /**
+    * Return true if this ir_constant represents the given value.
+    *
+    * For vectors, this checks that each component is the given value.
+    */
+   virtual bool is_value(float f, int i) const;
+   virtual bool is_zero() const;
+   virtual bool is_one() const;
+   virtual bool is_negative_one() const;
+
+   /**
+    * Return true for constants that could be stored as 16-bit unsigned values.
+    *
+    * Note that this will return true even for signed integer ir_constants, as
+    * long as the value is non-negative and fits in 16-bits.
+    */
+   virtual bool is_uint16_constant() const;
+
+   /**
+    * Value of the constant.
+    *
+    * The field used to back the values supplied by the constant is determined
+    * by the type associated with the \c ir_instruction.  Constants may be
+    * scalars, vectors, or matrices.
+    */
+   union ir_constant_data value;
+
+   /* Array elements */
+   ir_constant **array_elements;
+
+   /* Structure fields */
+   exec_list components;
+
+private:
+   /**
+    * Parameterless constructor only used by the clone method
+    */
+   ir_constant(void);
+};
+
+/**
+ * IR instruction to emit a vertex in a geometry shader.
+ */
+class ir_emit_vertex : public ir_instruction {
+public:
+   ir_emit_vertex(ir_rvalue *stream)
+      : ir_instruction(ir_type_emit_vertex),
+        stream(stream)
+   {
+      assert(stream);
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_emit_vertex *clone(void *mem_ctx, struct hash_table *ht) const
+   {
+      return new(mem_ctx) ir_emit_vertex(this->stream->clone(mem_ctx, ht));
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   int stream_id() const
+   {
+      return stream->as_constant()->value.i[0];
+   }
+
+   ir_rvalue *stream;
+};
+
+/**
+ * IR instruction to complete the current primitive and start a new one in a
+ * geometry shader.
+ */
+class ir_end_primitive : public ir_instruction {
+public:
+   ir_end_primitive(ir_rvalue *stream)
+      : ir_instruction(ir_type_end_primitive),
+        stream(stream)
+   {
+      assert(stream);
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_end_primitive *clone(void *mem_ctx, struct hash_table *ht) const
+   {
+      return new(mem_ctx) ir_end_primitive(this->stream->clone(mem_ctx, ht));
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+
+   int stream_id() const
+   {
+      return stream->as_constant()->value.i[0];
+   }
+
+   ir_rvalue *stream;
+};
+
+/**
+ * IR instruction for tessellation control and compute shader barrier.
+ */
+class ir_barrier : public ir_instruction {
+public:
+   ir_barrier()
+      : ir_instruction(ir_type_barrier)
+   {
+   }
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_barrier *clone(void *mem_ctx, struct hash_table *) const
+   {
+      return new(mem_ctx) ir_barrier();
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+};
+
+/*@}*/
+
+/**
+ * Apply a visitor to each IR node in a list
+ */
+void
+visit_exec_list(exec_list *list, ir_visitor *visitor);
+
+/**
+ * Validate invariants on each IR node in a list
+ */
+void validate_ir_tree(exec_list *instructions);
+
+struct _mesa_glsl_parse_state;
+struct gl_shader_program;
+
+/**
+ * Detect whether an unlinked shader contains static recursion
+ *
+ * If the list of instructions is determined to contain static recursion,
+ * \c _mesa_glsl_error will be called to emit error messages for each function
+ * that is in the recursion cycle.
+ */
+void
+detect_recursion_unlinked(struct _mesa_glsl_parse_state *state,
+			  exec_list *instructions);
+
+/**
+ * Detect whether a linked shader contains static recursion
+ *
+ * If the list of instructions is determined to contain static recursion,
+ * \c link_error_printf will be called to emit error messages for each function
+ * that is in the recursion cycle.  In addition,
+ * \c gl_shader_program::LinkStatus will be set to false.
+ */
+void
+detect_recursion_linked(struct gl_shader_program *prog,
+			exec_list *instructions);
+
+/**
+ * Make a clone of each IR instruction in a list
+ *
+ * \param in   List of IR instructions that are to be cloned
+ * \param out  List to hold the cloned instructions
+ */
+void
+clone_ir_list(void *mem_ctx, exec_list *out, const exec_list *in);
+
+extern void
+_mesa_glsl_initialize_variables(exec_list *instructions,
+				struct _mesa_glsl_parse_state *state);
+
+extern void
+_mesa_glsl_initialize_derived_variables(gl_shader *shader);
+
+extern void
+_mesa_glsl_initialize_functions(_mesa_glsl_parse_state *state);
+
+extern void
+_mesa_glsl_initialize_builtin_functions();
+
+extern ir_function_signature *
+_mesa_glsl_find_builtin_function(_mesa_glsl_parse_state *state,
+                                 const char *name, exec_list *actual_parameters);
+
+extern ir_function *
+_mesa_glsl_find_builtin_function_by_name(const char *name);
+
+extern gl_shader *
+_mesa_glsl_get_builtin_function_shader(void);
+
+extern ir_function_signature *
+_mesa_get_main_function_signature(gl_shader *sh);
+
+extern void
+_mesa_glsl_release_functions(void);
+
+extern void
+_mesa_glsl_release_builtin_functions(void);
+
+extern void
+reparent_ir(exec_list *list, void *mem_ctx);
+
+struct glsl_symbol_table;
+
+extern void
+import_prototypes(const exec_list *source, exec_list *dest,
+		  struct glsl_symbol_table *symbols, void *mem_ctx);
+
+extern bool
+ir_has_call(ir_instruction *ir);
+
+extern void
+do_set_program_inouts(exec_list *instructions, struct gl_program *prog,
+                      gl_shader_stage shader_stage);
+
+extern char *
+prototype_string(const glsl_type *return_type, const char *name,
+		 exec_list *parameters);
+
+const char *
+mode_string(const ir_variable *var);
+
+/**
+ * Built-in / reserved GL variables names start with "gl_"
+ */
+static inline bool
+is_gl_identifier(const char *s)
+{
+   return s && s[0] == 'g' && s[1] == 'l' && s[2] == '_';
+}
+
+extern "C" {
+#endif /* __cplusplus */
+
+extern void _mesa_print_ir(FILE *f, struct exec_list *instructions,
+                           struct _mesa_glsl_parse_state *state);
+
+extern void
+fprint_ir(FILE *f, const void *instruction);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+unsigned
+vertices_per_prim(GLenum prim);
+
+#endif /* IR_H */