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, 0 insertions, 640 deletions

diff --git a/src/glsl/loop_analysis.cpp b/src/glsl/loop_analysis.cpp
deleted file mode 100644
index 096a80abb34..00000000000
--- a/src/glsl/loop_analysis.cpp
+++ /dev/null
@@ -1,640 +0,0 @@
-/*
- * 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.
- */
-
-#include "compiler/glsl_types.h"
-#include "loop_analysis.h"
-#include "ir_hierarchical_visitor.h"
-
-static bool is_loop_terminator(ir_if *ir);
-
-static bool all_expression_operands_are_loop_constant(ir_rvalue *,
-						      hash_table *);
-
-static ir_rvalue *get_basic_induction_increment(ir_assignment *, hash_table *);
-
-
-/**
- * Record the fact that the given loop variable was referenced inside the loop.
- *
- * \arg in_assignee is true if the reference was on the LHS of an assignment.
- *
- * \arg in_conditional_code_or_nested_loop is true if the reference occurred
- * inside an if statement or a nested loop.
- *
- * \arg current_assignment is the ir_assignment node that the loop variable is
- * on the LHS of, if any (ignored if \c in_assignee is false).
- */
-void
-loop_variable::record_reference(bool in_assignee,
-                                bool in_conditional_code_or_nested_loop,
-                                ir_assignment *current_assignment)
-{
-   if (in_assignee) {
-      assert(current_assignment != NULL);
-
-      if (in_conditional_code_or_nested_loop ||
-          current_assignment->condition != NULL) {
-         this->conditional_or_nested_assignment = true;
-      }
-
-      if (this->first_assignment == NULL) {
-         assert(this->num_assignments == 0);
-
-         this->first_assignment = current_assignment;
-      }
-
-      this->num_assignments++;
-   } else if (this->first_assignment == current_assignment) {
-      /* This catches the case where the variable is used in the RHS of an
-       * assignment where it is also in the LHS.
-       */
-      this->read_before_write = true;
-   }
-}
-
-
-loop_state::loop_state()
-{
-   this->ht = hash_table_ctor(0, hash_table_pointer_hash,
-			      hash_table_pointer_compare);
-   this->mem_ctx = ralloc_context(NULL);
-   this->loop_found = false;
-}
-
-
-loop_state::~loop_state()
-{
-   hash_table_dtor(this->ht);
-   ralloc_free(this->mem_ctx);
-}
-
-
-loop_variable_state *
-loop_state::insert(ir_loop *ir)
-{
-   loop_variable_state *ls = new(this->mem_ctx) loop_variable_state;
-
-   hash_table_insert(this->ht, ls, ir);
-   this->loop_found = true;
-
-   return ls;
-}
-
-
-loop_variable_state *
-loop_state::get(const ir_loop *ir)
-{
-   return (loop_variable_state *) hash_table_find(this->ht, ir);
-}
-
-
-loop_variable *
-loop_variable_state::get(const ir_variable *ir)
-{
-   return (loop_variable *) hash_table_find(this->var_hash, ir);
-}
-
-
-loop_variable *
-loop_variable_state::insert(ir_variable *var)
-{
-   void *mem_ctx = ralloc_parent(this);
-   loop_variable *lv = rzalloc(mem_ctx, loop_variable);
-
-   lv->var = var;
-
-   hash_table_insert(this->var_hash, lv, lv->var);
-   this->variables.push_tail(lv);
-
-   return lv;
-}
-
-
-loop_terminator *
-loop_variable_state::insert(ir_if *if_stmt)
-{
-   void *mem_ctx = ralloc_parent(this);
-   loop_terminator *t = new(mem_ctx) loop_terminator();
-
-   t->ir = if_stmt;
-   this->terminators.push_tail(t);
-
-   return t;
-}
-
-
-/**
- * If the given variable already is recorded in the state for this loop,
- * return the corresponding loop_variable object that records information
- * about it.
- *
- * Otherwise, create a new loop_variable object to record information about
- * the variable, and set its \c read_before_write field appropriately based on
- * \c in_assignee.
- *
- * \arg in_assignee is true if this variable was encountered on the LHS of an
- * assignment.
- */
-loop_variable *
-loop_variable_state::get_or_insert(ir_variable *var, bool in_assignee)
-{
-   loop_variable *lv = this->get(var);
-
-   if (lv == NULL) {
-      lv = this->insert(var);
-      lv->read_before_write = !in_assignee;
-   }
-
-   return lv;
-}
-
-
-namespace {
-
-class loop_analysis : public ir_hierarchical_visitor {
-public:
-   loop_analysis(loop_state *loops);
-
-   virtual ir_visitor_status visit(ir_loop_jump *);
-   virtual ir_visitor_status visit(ir_dereference_variable *);
-
-   virtual ir_visitor_status visit_enter(ir_call *);
-
-   virtual ir_visitor_status visit_enter(ir_loop *);
-   virtual ir_visitor_status visit_leave(ir_loop *);
-   virtual ir_visitor_status visit_enter(ir_assignment *);
-   virtual ir_visitor_status visit_leave(ir_assignment *);
-   virtual ir_visitor_status visit_enter(ir_if *);
-   virtual ir_visitor_status visit_leave(ir_if *);
-
-   loop_state *loops;
-
-   int if_statement_depth;
-
-   ir_assignment *current_assignment;
-
-   exec_list state;
-};
-
-} /* anonymous namespace */
-
-loop_analysis::loop_analysis(loop_state *loops)
-   : loops(loops), if_statement_depth(0), current_assignment(NULL)
-{
-   /* empty */
-}
-
-
-ir_visitor_status
-loop_analysis::visit(ir_loop_jump *ir)
-{
-   (void) ir;
-
-   assert(!this->state.is_empty());
-
-   loop_variable_state *const ls =
-      (loop_variable_state *) this->state.get_head();
-
-   ls->num_loop_jumps++;
-
-   return visit_continue;
-}
-
-
-ir_visitor_status
-loop_analysis::visit_enter(ir_call *)
-{
-   /* Mark every loop that we're currently analyzing as containing an ir_call
-    * (even those at outer nesting levels).
-    */
-   foreach_in_list(loop_variable_state, ls, &this->state) {
-      ls->contains_calls = true;
-   }
-
-   return visit_continue_with_parent;
-}
-
-
-ir_visitor_status
-loop_analysis::visit(ir_dereference_variable *ir)
-{
-   /* If we're not somewhere inside a loop, there's nothing to do.
-    */
-   if (this->state.is_empty())
-      return visit_continue;
-
-   bool nested = false;
-
-   foreach_in_list(loop_variable_state, ls, &this->state) {
-      ir_variable *var = ir->variable_referenced();
-      loop_variable *lv = ls->get_or_insert(var, this->in_assignee);
-
-      lv->record_reference(this->in_assignee,
-                           nested || this->if_statement_depth > 0,
-                           this->current_assignment);
-      nested = true;
-   }
-
-   return visit_continue;
-}
-
-ir_visitor_status
-loop_analysis::visit_enter(ir_loop *ir)
-{
-   loop_variable_state *ls = this->loops->insert(ir);
-   this->state.push_head(ls);
-
-   return visit_continue;
-}
-
-ir_visitor_status
-loop_analysis::visit_leave(ir_loop *ir)
-{
-   loop_variable_state *const ls =
-      (loop_variable_state *) this->state.pop_head();
-
-   /* Function calls may contain side effects.  These could alter any of our
-    * variables in ways that cannot be known, and may even terminate shader
-    * execution (say, calling discard in the fragment shader).  So we can't
-    * rely on any of our analysis about assignments to variables.
-    *
-    * We could perform some conservative analysis (prove there's no statically
-    * possible assignment, etc.) but it isn't worth it for now; function
-    * inlining will allow us to unroll loops anyway.
-    */
-   if (ls->contains_calls)
-      return visit_continue;
-
-   foreach_in_list(ir_instruction, node, &ir->body_instructions) {
-      /* Skip over declarations at the start of a loop.
-       */
-      if (node->as_variable())
-	 continue;
-
-      ir_if *if_stmt = ((ir_instruction *) node)->as_if();
-
-      if ((if_stmt != NULL) && is_loop_terminator(if_stmt))
-	 ls->insert(if_stmt);
-      else
-	 break;
-   }
-
-
-   foreach_in_list_safe(loop_variable, lv, &ls->variables) {
-      /* Move variables that are already marked as being loop constant to
-       * a separate list.  These trivially don't need to be tested.
-       */
-      if (lv->is_loop_constant()) {
-	 lv->remove();
-	 ls->constants.push_tail(lv);
-      }
-   }
-
-   /* Each variable assigned in the loop that isn't already marked as being loop
-    * constant might still be loop constant.  The requirements at this point
-    * are:
-    *
-    *    - Variable is written before it is read.
-    *
-    *    - Only one assignment to the variable.
-    *
-    *    - All operands on the RHS of the assignment are also loop constants.
-    *
-    * The last requirement is the reason for the progress loop.  A variable
-    * marked as a loop constant on one pass may allow other variables to be
-    * marked as loop constant on following passes.
-    */
-   bool progress;
-   do {
-      progress = false;
-
-      foreach_in_list_safe(loop_variable, lv, &ls->variables) {
-	 if (lv->conditional_or_nested_assignment || (lv->num_assignments > 1))
-	    continue;
-
-	 /* Process the RHS of the assignment.  If all of the variables
-	  * accessed there are loop constants, then add this
-	  */
-	 ir_rvalue *const rhs = lv->first_assignment->rhs;
-	 if (all_expression_operands_are_loop_constant(rhs, ls->var_hash)) {
-	    lv->rhs_clean = true;
-
-	    if (lv->is_loop_constant()) {
-	       progress = true;
-
-	       lv->remove();
-	       ls->constants.push_tail(lv);
-	    }
-	 }
-      }
-   } while (progress);
-
-   /* The remaining variables that are not loop invariant might be loop
-    * induction variables.
-    */
-   foreach_in_list_safe(loop_variable, lv, &ls->variables) {
-      /* If there is more than one assignment to a variable, it cannot be a
-       * loop induction variable.  This isn't strictly true, but this is a
-       * very simple induction variable detector, and it can't handle more
-       * complex cases.
-       */
-      if (lv->num_assignments > 1)
-	 continue;
-
-      /* All of the variables with zero assignments in the loop are loop
-       * invariant, and they should have already been filtered out.
-       */
-      assert(lv->num_assignments == 1);
-      assert(lv->first_assignment != NULL);
-
-      /* The assignment to the variable in the loop must be unconditional and
-       * not inside a nested loop.
-       */
-      if (lv->conditional_or_nested_assignment)
-	 continue;
-
-      /* Basic loop induction variables have a single assignment in the loop
-       * that has the form 'VAR = VAR + i' or 'VAR = VAR - i' where i is a
-       * loop invariant.
-       */
-      ir_rvalue *const inc =
-	 get_basic_induction_increment(lv->first_assignment, ls->var_hash);
-      if (inc != NULL) {
-	 lv->increment = inc;
-
-	 lv->remove();
-	 ls->induction_variables.push_tail(lv);
-      }
-   }
-
-   /* Search the loop terminating conditions for those of the form 'i < c'
-    * where i is a loop induction variable, c is a constant, and < is any
-    * relative operator.  From each of these we can infer an iteration count.
-    * Also figure out which terminator (if any) produces the smallest
-    * iteration count--this is the limiting terminator.
-    */
-   foreach_in_list(loop_terminator, t, &ls->terminators) {
-      ir_if *if_stmt = t->ir;
-
-      /* If-statements can be either 'if (expr)' or 'if (deref)'.  We only care
-       * about the former here.
-       */
-      ir_expression *cond = if_stmt->condition->as_expression();
-      if (cond == NULL)
-	 continue;
-
-      switch (cond->operation) {
-      case ir_binop_less:
-      case ir_binop_greater:
-      case ir_binop_lequal:
-      case ir_binop_gequal: {
-	 /* The expressions that we care about will either be of the form
-	  * 'counter < limit' or 'limit < counter'.  Figure out which is
-	  * which.
-	  */
-	 ir_rvalue *counter = cond->operands[0]->as_dereference_variable();
-	 ir_constant *limit = cond->operands[1]->as_constant();
-	 enum ir_expression_operation cmp = cond->operation;
-
-	 if (limit == NULL) {
-	    counter = cond->operands[1]->as_dereference_variable();
-	    limit = cond->operands[0]->as_constant();
-
-	    switch (cmp) {
-	    case ir_binop_less:    cmp = ir_binop_greater; break;
-	    case ir_binop_greater: cmp = ir_binop_less;    break;
-	    case ir_binop_lequal:  cmp = ir_binop_gequal;  break;
-	    case ir_binop_gequal:  cmp = ir_binop_lequal;  break;
-	    default: assert(!"Should not get here.");
-	    }
-	 }
-
-	 if ((counter == NULL) || (limit == NULL))
-	    break;
-
-	 ir_variable *var = counter->variable_referenced();
-
-	 ir_rvalue *init = find_initial_value(ir, var);
-
-         loop_variable *lv = ls->get(var);
-         if (lv != NULL && lv->is_induction_var()) {
-            t->iterations = calculate_iterations(init, limit, lv->increment,
-                                                 cmp);
-
-            if (t->iterations >= 0 &&
-                (ls->limiting_terminator == NULL ||
-                 t->iterations < ls->limiting_terminator->iterations)) {
-               ls->limiting_terminator = t;
-            }
-         }
-         break;
-      }
-
-      default:
-         break;
-      }
-   }
-
-   return visit_continue;
-}
-
-ir_visitor_status
-loop_analysis::visit_enter(ir_if *ir)
-{
-   (void) ir;
-
-   if (!this->state.is_empty())
-      this->if_statement_depth++;
-
-   return visit_continue;
-}
-
-ir_visitor_status
-loop_analysis::visit_leave(ir_if *ir)
-{
-   (void) ir;
-
-   if (!this->state.is_empty())
-      this->if_statement_depth--;
-
-   return visit_continue;
-}
-
-ir_visitor_status
-loop_analysis::visit_enter(ir_assignment *ir)
-{
-   /* If we're not somewhere inside a loop, there's nothing to do.
-    */
-   if (this->state.is_empty())
-      return visit_continue_with_parent;
-
-   this->current_assignment = ir;
-
-   return visit_continue;
-}
-
-ir_visitor_status
-loop_analysis::visit_leave(ir_assignment *ir)
-{
-   /* Since the visit_enter exits with visit_continue_with_parent for this
-    * case, the loop state stack should never be empty here.
-    */
-   assert(!this->state.is_empty());
-
-   assert(this->current_assignment == ir);
-   this->current_assignment = NULL;
-
-   return visit_continue;
-}
-
-
-class examine_rhs : public ir_hierarchical_visitor {
-public:
-   examine_rhs(hash_table *loop_variables)
-   {
-      this->only_uses_loop_constants = true;
-      this->loop_variables = loop_variables;
-   }
-
-   virtual ir_visitor_status visit(ir_dereference_variable *ir)
-   {
-      loop_variable *lv =
-	 (loop_variable *) hash_table_find(this->loop_variables, ir->var);
-
-      assert(lv != NULL);
-
-      if (lv->is_loop_constant()) {
-	 return visit_continue;
-      } else {
-	 this->only_uses_loop_constants = false;
-	 return visit_stop;
-      }
-   }
-
-   hash_table *loop_variables;
-   bool only_uses_loop_constants;
-};
-
-
-bool
-all_expression_operands_are_loop_constant(ir_rvalue *ir, hash_table *variables)
-{
-   examine_rhs v(variables);
-
-   ir->accept(&v);
-
-   return v.only_uses_loop_constants;
-}
-
-
-ir_rvalue *
-get_basic_induction_increment(ir_assignment *ir, hash_table *var_hash)
-{
-   /* The RHS must be a binary expression.
-    */
-   ir_expression *const rhs = ir->rhs->as_expression();
-   if ((rhs == NULL)
-       || ((rhs->operation != ir_binop_add)
-	   && (rhs->operation != ir_binop_sub)))
-      return NULL;
-
-   /* One of the of operands of the expression must be the variable assigned.
-    * If the operation is subtraction, the variable in question must be the
-    * "left" operand.
-    */
-   ir_variable *const var = ir->lhs->variable_referenced();
-
-   ir_variable *const op0 = rhs->operands[0]->variable_referenced();
-   ir_variable *const op1 = rhs->operands[1]->variable_referenced();
-
-   if (((op0 != var) && (op1 != var))
-       || ((op1 == var) && (rhs->operation == ir_binop_sub)))
-      return NULL;
-
-   ir_rvalue *inc = (op0 == var) ? rhs->operands[1] : rhs->operands[0];
-
-   if (inc->as_constant() == NULL) {
-      ir_variable *const inc_var = inc->variable_referenced();
-      if (inc_var != NULL) {
-	 loop_variable *lv =
-	    (loop_variable *) hash_table_find(var_hash, inc_var);
-
-         if (lv == NULL || !lv->is_loop_constant()) {
-            assert(lv != NULL);
-            inc = NULL;
-         }
-      } else
-	 inc = NULL;
-   }
-
-   if ((inc != NULL) && (rhs->operation == ir_binop_sub)) {
-      void *mem_ctx = ralloc_parent(ir);
-
-      inc = new(mem_ctx) ir_expression(ir_unop_neg,
-				       inc->type,
-				       inc->clone(mem_ctx, NULL),
-				       NULL);
-   }
-
-   return inc;
-}
-
-
-/**
- * Detect whether an if-statement is a loop terminating condition
- *
- * Detects if-statements of the form
- *
- *  (if (expression bool ...) (break))
- */
-bool
-is_loop_terminator(ir_if *ir)
-{
-   if (!ir->else_instructions.is_empty())
-      return false;
-
-   ir_instruction *const inst =
-      (ir_instruction *) ir->then_instructions.get_head();
-   if (inst == NULL)
-      return false;
-
-   if (inst->ir_type != ir_type_loop_jump)
-      return false;
-
-   ir_loop_jump *const jump = (ir_loop_jump *) inst;
-   if (jump->mode != ir_loop_jump::jump_break)
-      return false;
-
-   return true;
-}
-
-
-loop_state *
-analyze_loop_variables(exec_list *instructions)
-{
-   loop_state *loops = new loop_state;
-   loop_analysis v(loops);
-
-   v.run(instructions);
-   return v.loops;
-}