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Diffstat (limited to 'src/glsl/ir_algebraic.cpp')
| -rw-r--r-- | src/glsl/ir_algebraic.cpp | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/src/glsl/ir_algebraic.cpp b/src/glsl/ir_algebraic.cpp new file mode 100644 index 00000000000..a66c820a278 --- /dev/null +++ b/src/glsl/ir_algebraic.cpp @@ -0,0 +1,392 @@ +/* + * 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; + } + + 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); + 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; +} + +ir_rvalue * +ir_algebraic_visitor::handle_expression(ir_expression *ir) +{ + ir_constant *op_const[2] = {NULL, NULL}; + ir_expression *op_expr[2] = {NULL, NULL}; + 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(); + } + + 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; + + 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(ir) 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 ir->operands[1]; + } + if (is_vec_zero(op_const[1])) { + this->progress = true; + return 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; + return new(ir) ir_expression(ir_unop_neg, + ir->type, + ir->operands[1], + NULL); + } + if (is_vec_zero(op_const[1])) { + this->progress = true; + return ir->operands[0]; + } + break; + + case ir_binop_mul: + if (is_vec_one(op_const[0])) { + this->progress = true; + return ir->operands[1]; + } + if (is_vec_one(op_const[1])) { + this->progress = true; + return 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; + return new(ir) ir_expression(ir_unop_rcp, + ir->type, + ir->operands[1], + NULL); + } + if (is_vec_one(op_const[1])) { + this->progress = true; + return ir->operands[0]; + } + 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; + return new(ir) ir_expression(ir_unop_rsq, + ir->type, + op_expr[0]->operands[0], + NULL); + } + + 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; +} |