glsl: Rename various ir_* files to lower_* and opt_*.

This helps distinguish between lowering passes, optimization passes, and
other compiler code.

1 files changed, 474 insertions, 0 deletions

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
new file mode 100644
index 0000000000..2ed66db476
--- /dev/null
+++ b/src/glsl/opt_algebraic.cpp
@@ -0,0 +1,474 @@
+/*
+ * 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.
+ */
+
+/**
+ * \file ir_algebraic.cpp
+ *
+ * Takes advantage of association, commutivity, and other algebraic
+ * properties to simplify expressions.
+ */
+
+#include "ir.h"
+#include "ir_visitor.h"
+#include "ir_rvalue_visitor.h"
+#include "ir_optimization.h"
+#include "glsl_types.h"
+
+/**
+ * Visitor class for replacing expressions with ir_constant values.
+ */
+
+class ir_algebraic_visitor : public ir_rvalue_visitor {
+public:
+   ir_algebraic_visitor()
+   {
+      this->progress = false;
+      this->mem_ctx = NULL;
+   }
+
+   virtual ~ir_algebraic_visitor()
+   {
+   }
+
+   ir_rvalue *handle_expression(ir_expression *ir);
+   void handle_rvalue(ir_rvalue **rvalue);
+   bool reassociate_constant(ir_expression *ir1,
+			     int const_index,
+			     ir_constant *constant,
+			     ir_expression *ir2);
+   void reassociate_operands(ir_expression *ir1,
+			     int op1,
+			     ir_expression *ir2,
+			     int op2);
+   ir_rvalue *swizzle_if_required(ir_expression *expr,
+				  ir_rvalue *operand);
+
+   void *mem_ctx;
+
+   bool progress;
+};
+
+static bool
+is_vec_zero(ir_constant *ir)
+{
+   int c;
+
+   if (!ir)
+      return false;
+   if (!ir->type->is_scalar() &&
+       !ir->type->is_vector())
+      return false;
+
+   for (c = 0; c < ir->type->vector_elements; c++) {
+      switch (ir->type->base_type) {
+      case GLSL_TYPE_FLOAT:
+	 if (ir->value.f[c] != 0.0)
+	    return false;
+	 break;
+      case GLSL_TYPE_INT:
+	 if (ir->value.i[c] != 0)
+	    return false;
+	 break;
+      case GLSL_TYPE_UINT:
+	 if (ir->value.u[c] != 0)
+	    return false;
+	 break;
+      case GLSL_TYPE_BOOL:
+	 if (ir->value.b[c] != false)
+	    return false;
+	 break;
+      default:
+	 assert(!"bad base type");
+	 return false;
+      }
+   }
+
+   return true;
+}
+
+static bool
+is_vec_one(ir_constant *ir)
+{
+   int c;
+
+   if (!ir)
+      return false;
+   if (!ir->type->is_scalar() &&
+       !ir->type->is_vector())
+      return false;
+
+   for (c = 0; c < ir->type->vector_elements; c++) {
+      switch (ir->type->base_type) {
+      case GLSL_TYPE_FLOAT:
+	 if (ir->value.f[c] != 1.0)
+	    return false;
+	 break;
+      case GLSL_TYPE_INT:
+	 if (ir->value.i[c] != 1)
+	    return false;
+	 break;
+      case GLSL_TYPE_UINT:
+	 if (ir->value.u[c] != 1)
+	    return false;
+	 break;
+      case GLSL_TYPE_BOOL:
+	 if (ir->value.b[c] != true)
+	    return false;
+	 break;
+      default:
+	 assert(!"bad base type");
+	 return false;
+      }
+   }
+
+   return true;
+}
+
+static void
+update_type(ir_expression *ir)
+{
+   if (ir->operands[0]->type->is_vector())
+      ir->type = ir->operands[0]->type;
+   else
+      ir->type = ir->operands[1]->type;
+}
+
+void
+ir_algebraic_visitor::reassociate_operands(ir_expression *ir1,
+					   int op1,
+					   ir_expression *ir2,
+					   int op2)
+{
+   ir_rvalue *temp = ir2->operands[op2];
+   ir2->operands[op2] = ir1->operands[op1];
+   ir1->operands[op1] = temp;
+
+   /* Update the type of ir2.  The type of ir1 won't have changed --
+    * base types matched, and at least one of the operands of the 2
+    * binops is still a vector if any of them were.
+    */
+   update_type(ir2);
+
+   this->progress = true;
+}
+
+/**
+ * Reassociates a constant down a tree of adds or multiplies.
+ *
+ * Consider (2 * (a * (b * 0.5))).  We want to send up with a * b.
+ */
+bool
+ir_algebraic_visitor::reassociate_constant(ir_expression *ir1, int const_index,
+					   ir_constant *constant,
+					   ir_expression *ir2)
+{
+   if (!ir2 || ir1->operation != ir2->operation)
+      return false;
+
+   /* Don't want to even think about matrices. */
+   if (ir1->operands[0]->type->is_matrix() ||
+       ir1->operands[0]->type->is_matrix() ||
+       ir2->operands[1]->type->is_matrix() ||
+       ir2->operands[1]->type->is_matrix())
+      return false;
+
+   ir_constant *ir2_const[2];
+   ir2_const[0] = ir2->operands[0]->constant_expression_value();
+   ir2_const[1] = ir2->operands[1]->constant_expression_value();
+
+   if (ir2_const[0] && ir2_const[1])
+      return false;
+
+   if (ir2_const[0]) {
+      reassociate_operands(ir1, const_index, ir2, 1);
+      return true;
+   } else if (ir2_const[1]) {
+      reassociate_operands(ir1, const_index, ir2, 0);
+      return true;
+   }
+
+   if (reassociate_constant(ir1, const_index, constant,
+			    ir2->operands[0]->as_expression())) {
+      update_type(ir2);
+      return true;
+   }
+
+   if (reassociate_constant(ir1, const_index, constant,
+			    ir2->operands[1]->as_expression())) {
+      update_type(ir2);
+      return true;
+   }
+
+   return false;
+}
+
+/* When eliminating an expression and just returning one of its operands,
+ * we may need to swizzle that operand out to a vector if the expression was
+ * vector type.
+ */
+ir_rvalue *
+ir_algebraic_visitor::swizzle_if_required(ir_expression *expr,
+					  ir_rvalue *operand)
+{
+   if (expr->type->is_vector() && operand->type->is_scalar()) {
+      return new(mem_ctx) ir_swizzle(operand, 0, 0, 0, 0,
+				     expr->type->vector_elements);
+   } else
+      return operand;
+}
+
+ir_rvalue *
+ir_algebraic_visitor::handle_expression(ir_expression *ir)
+{
+   ir_constant *op_const[2] = {NULL, NULL};
+   ir_expression *op_expr[2] = {NULL, NULL};
+   ir_expression *temp;
+   unsigned int i;
+
+   for (i = 0; i < ir->get_num_operands(); i++) {
+      if (ir->operands[i]->type->is_matrix())
+	 return ir;
+
+      op_const[i] = ir->operands[i]->constant_expression_value();
+      op_expr[i] = ir->operands[i]->as_expression();
+   }
+
+   if (this->mem_ctx == NULL)
+      this->mem_ctx = talloc_parent(ir);
+
+   switch (ir->operation) {
+   case ir_unop_logic_not: {
+      enum ir_expression_operation new_op = ir_unop_logic_not;
+
+      if (op_expr[0] == NULL)
+	 break;
+
+      switch (op_expr[0]->operation) {
+      case ir_binop_less:    new_op = ir_binop_gequal;  break;
+      case ir_binop_greater: new_op = ir_binop_lequal;  break;
+      case ir_binop_lequal:  new_op = ir_binop_greater; break;
+      case ir_binop_gequal:  new_op = ir_binop_less;    break;
+      case ir_binop_equal:   new_op = ir_binop_nequal;  break;
+      case ir_binop_nequal:  new_op = ir_binop_equal;   break;
+      case ir_binop_all_equal:   new_op = ir_binop_any_nequal;  break;
+      case ir_binop_any_nequal:  new_op = ir_binop_all_equal;   break;
+
+      default:
+	 /* The default case handler is here to silence a warning from GCC.
+	  */
+	 break;
+      }
+
+      if (new_op != ir_unop_logic_not) {
+	 this->progress = true;
+	 return new(mem_ctx) ir_expression(new_op,
+					   ir->type,
+					   op_expr[0]->operands[0],
+					   op_expr[0]->operands[1]);
+      }
+
+      break;
+   }
+
+   case ir_binop_add:
+      if (is_vec_zero(op_const[0])) {
+	 this->progress = true;
+	 return swizzle_if_required(ir, ir->operands[1]);
+      }
+      if (is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return swizzle_if_required(ir, ir->operands[0]);
+      }
+
+      /* Reassociate addition of constants so that we can do constant
+       * folding.
+       */
+      if (op_const[0] && !op_const[1])
+	 reassociate_constant(ir, 0, op_const[0],
+			      ir->operands[1]->as_expression());
+      if (op_const[1] && !op_const[0])
+	 reassociate_constant(ir, 1, op_const[1],
+			      ir->operands[0]->as_expression());
+      break;
+
+   case ir_binop_sub:
+      if (is_vec_zero(op_const[0])) {
+	 this->progress = true;
+	 temp = new(mem_ctx) ir_expression(ir_unop_neg,
+					   ir->operands[1]->type,
+					   ir->operands[1],
+					   NULL);
+	 return swizzle_if_required(ir, temp);
+      }
+      if (is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return swizzle_if_required(ir, ir->operands[0]);
+      }
+      break;
+
+   case ir_binop_mul:
+      if (is_vec_one(op_const[0])) {
+	 this->progress = true;
+	 return swizzle_if_required(ir, ir->operands[1]);
+      }
+      if (is_vec_one(op_const[1])) {
+	 this->progress = true;
+	 return swizzle_if_required(ir, ir->operands[0]);
+      }
+
+      if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return ir_constant::zero(ir, ir->type);
+      }
+
+      /* Reassociate multiplication of constants so that we can do
+       * constant folding.
+       */
+      if (op_const[0] && !op_const[1])
+	 reassociate_constant(ir, 0, op_const[0],
+			      ir->operands[1]->as_expression());
+      if (op_const[1] && !op_const[0])
+	 reassociate_constant(ir, 1, op_const[1],
+			      ir->operands[0]->as_expression());
+
+      break;
+
+   case ir_binop_div:
+      if (is_vec_one(op_const[0]) && ir->type->base_type == GLSL_TYPE_FLOAT) {
+	 this->progress = true;
+	 temp = new(mem_ctx) ir_expression(ir_unop_rcp,
+					   ir->operands[1]->type,
+					   ir->operands[1],
+					   NULL);
+	 return swizzle_if_required(ir, temp);
+      }
+      if (is_vec_one(op_const[1])) {
+	 this->progress = true;
+	 return swizzle_if_required(ir, ir->operands[0]);
+      }
+      break;
+
+   case ir_binop_logic_and:
+      /* FINISHME: Also simplify (a && a) to (a). */
+      if (is_vec_one(op_const[0])) {
+	 this->progress = true;
+	 return ir->operands[1];
+      } else if (is_vec_one(op_const[1])) {
+	 this->progress = true;
+	 return ir->operands[0];
+      } else if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return ir_constant::zero(mem_ctx, ir->type);
+      }
+      break;
+
+   case ir_binop_logic_xor:
+      /* FINISHME: Also simplify (a ^^ a) to (false). */
+      if (is_vec_zero(op_const[0])) {
+	 this->progress = true;
+	 return ir->operands[1];
+      } else if (is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return ir->operands[0];
+      } else if (is_vec_one(op_const[0])) {
+	 this->progress = true;
+	 return new(mem_ctx) ir_expression(ir_unop_logic_not, ir->type,
+					   ir->operands[1], NULL);
+      } else if (is_vec_one(op_const[1])) {
+	 this->progress = true;
+	 return new(mem_ctx) ir_expression(ir_unop_logic_not, ir->type,
+					   ir->operands[0], NULL);
+      }
+      break;
+
+   case ir_binop_logic_or:
+      /* FINISHME: Also simplify (a || a) to (a). */
+      if (is_vec_zero(op_const[0])) {
+	 this->progress = true;
+	 return ir->operands[1];
+      } else if (is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return ir->operands[0];
+      } else if (is_vec_one(op_const[0]) || is_vec_one(op_const[1])) {
+	 ir_constant_data data;
+
+	 for (unsigned i = 0; i < 16; i++)
+	    data.b[i] = true;
+
+	 this->progress = true;
+	 return new(mem_ctx) ir_constant(ir->type, &data);
+      }
+      break;
+
+   case ir_unop_rcp:
+      if (op_expr[0] && op_expr[0]->operation == ir_unop_rcp) {
+	 this->progress = true;
+	 return op_expr[0]->operands[0];
+      }
+
+      /* FINISHME: We should do rcp(rsq(x)) -> sqrt(x) for some
+       * backends, except that some backends will have done sqrt ->
+       * rcp(rsq(x)) and we don't want to undo it for them.
+       */
+
+      /* As far as we know, all backends are OK with rsq. */
+      if (op_expr[0] && op_expr[0]->operation == ir_unop_sqrt) {
+	 this->progress = true;
+	 temp = new(mem_ctx) ir_expression(ir_unop_rsq,
+					   op_expr[0]->operands[0]->type,
+					   op_expr[0]->operands[0],
+					   NULL);
+	 return swizzle_if_required(ir, temp);
+      }
+
+      break;
+
+   default:
+      break;
+   }
+
+   return ir;
+}
+
+void
+ir_algebraic_visitor::handle_rvalue(ir_rvalue **rvalue)
+{
+   if (!*rvalue)
+      return;
+
+   ir_expression *expr = (*rvalue)->as_expression();
+   if (!expr)
+      return;
+
+   *rvalue = handle_expression(expr);
+}
+
+bool
+do_algebraic(exec_list *instructions)
+{
+   ir_algebraic_visitor v;
+
+   visit_list_elements(&v, instructions);
+
+   return v.progress;
+}