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Diffstat (limited to 'src/compiler/glsl/opt_algebraic.cpp')
| -rw-r--r-- | src/compiler/glsl/opt_algebraic.cpp | 984 |
1 files changed, 984 insertions, 0 deletions
diff --git a/src/compiler/glsl/opt_algebraic.cpp b/src/compiler/glsl/opt_algebraic.cpp new file mode 100644 index 0000000..1e58062 --- /dev/null +++ b/src/compiler/glsl/opt_algebraic.cpp @@ -0,0 +1,984 @@ +/* + * 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 opt_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 "ir_builder.h" +#include "compiler/glsl_types.h" + +using namespace ir_builder; + +namespace { + +/** + * Visitor class for replacing expressions with ir_constant values. + */ + +class ir_algebraic_visitor : public ir_rvalue_visitor { +public: + ir_algebraic_visitor(bool native_integers, + const struct gl_shader_compiler_options *options) + : options(options) + { + this->progress = false; + this->mem_ctx = NULL; + this->native_integers = native_integers; + } + + 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); + + const struct gl_shader_compiler_options *options; + void *mem_ctx; + + bool native_integers; + bool progress; +}; + +} /* unnamed namespace */ + +static inline bool +is_vec_zero(ir_constant *ir) +{ + return (ir == NULL) ? false : ir->is_zero(); +} + +static inline bool +is_vec_one(ir_constant *ir) +{ + return (ir == NULL) ? false : ir->is_one(); +} + +static inline bool +is_vec_two(ir_constant *ir) +{ + return (ir == NULL) ? false : ir->is_value(2.0, 2); +} + +static inline bool +is_vec_four(ir_constant *ir) +{ + return (ir == NULL) ? false : ir->is_value(4.0, 4); +} + +static inline bool +is_vec_negative_one(ir_constant *ir) +{ + return (ir == NULL) ? false : ir->is_negative_one(); +} + +static inline bool +is_valid_vec_const(ir_constant *ir) +{ + if (ir == NULL) + return false; + + if (!ir->type->is_scalar() && !ir->type->is_vector()) + return false; + + return true; +} + +static inline bool +is_less_than_one(ir_constant *ir) +{ + assert(ir->type->base_type == GLSL_TYPE_FLOAT); + + if (!is_valid_vec_const(ir)) + return false; + + unsigned component = 0; + for (int c = 0; c < ir->type->vector_elements; c++) { + if (ir->get_float_component(c) < 1.0f) + component++; + } + + return (component == ir->type->vector_elements); +} + +static inline bool +is_greater_than_zero(ir_constant *ir) +{ + assert(ir->type->base_type == GLSL_TYPE_FLOAT); + + if (!is_valid_vec_const(ir)) + return false; + + unsigned component = 0; + for (int c = 0; c < ir->type->vector_elements; c++) { + if (ir->get_float_component(c) > 0.0f) + component++; + } + + return (component == ir->type->vector_elements); +} + +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; +} + +/* Recognize (v.x + v.y) + (v.z + v.w) as dot(v, 1.0) */ +static ir_expression * +try_replace_with_dot(ir_expression *expr0, ir_expression *expr1, void *mem_ctx) +{ + if (expr0 && expr0->operation == ir_binop_add && + expr0->type->is_float() && + expr1 && expr1->operation == ir_binop_add && + expr1->type->is_float()) { + ir_swizzle *x = expr0->operands[0]->as_swizzle(); + ir_swizzle *y = expr0->operands[1]->as_swizzle(); + ir_swizzle *z = expr1->operands[0]->as_swizzle(); + ir_swizzle *w = expr1->operands[1]->as_swizzle(); + + if (!x || x->mask.num_components != 1 || + !y || y->mask.num_components != 1 || + !z || z->mask.num_components != 1 || + !w || w->mask.num_components != 1) { + return NULL; + } + + bool swiz_seen[4] = {false, false, false, false}; + swiz_seen[x->mask.x] = true; + swiz_seen[y->mask.x] = true; + swiz_seen[z->mask.x] = true; + swiz_seen[w->mask.x] = true; + + if (!swiz_seen[0] || !swiz_seen[1] || + !swiz_seen[2] || !swiz_seen[3]) { + return NULL; + } + + if (x->val->equals(y->val) && + x->val->equals(z->val) && + x->val->equals(w->val)) { + return dot(x->val, new(mem_ctx) ir_constant(1.0f, 4)); + } + } + return NULL; +} + +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[1]->type->is_matrix() || + ir2->operands[0]->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[4] = {NULL, NULL, NULL, NULL}; + ir_expression *op_expr[4] = {NULL, NULL, NULL, NULL}; + unsigned int i; + + if (ir->operation == ir_binop_mul && + ir->operands[0]->type->is_matrix() && + ir->operands[1]->type->is_vector()) { + ir_expression *matrix_mul = ir->operands[0]->as_expression(); + + if (matrix_mul && matrix_mul->operation == ir_binop_mul && + matrix_mul->operands[0]->type->is_matrix() && + matrix_mul->operands[1]->type->is_matrix()) { + + return mul(matrix_mul->operands[0], + mul(matrix_mul->operands[1], ir->operands[1])); + } + } + + assert(ir->get_num_operands() <= 4); + 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 = ralloc_parent(ir); + + switch (ir->operation) { + case ir_unop_bit_not: + if (op_expr[0] && op_expr[0]->operation == ir_unop_bit_not) + return op_expr[0]->operands[0]; + break; + + case ir_unop_abs: + if (op_expr[0] == NULL) + break; + + switch (op_expr[0]->operation) { + case ir_unop_abs: + case ir_unop_neg: + return abs(op_expr[0]->operands[0]); + default: + break; + } + break; + + case ir_unop_neg: + if (op_expr[0] == NULL) + break; + + if (op_expr[0]->operation == ir_unop_neg) { + return op_expr[0]->operands[0]; + } + break; + + case ir_unop_exp: + if (op_expr[0] == NULL) + break; + + if (op_expr[0]->operation == ir_unop_log) { + return op_expr[0]->operands[0]; + } + break; + + case ir_unop_log: + if (op_expr[0] == NULL) + break; + + if (op_expr[0]->operation == ir_unop_exp) { + return op_expr[0]->operands[0]; + } + break; + + case ir_unop_exp2: + if (op_expr[0] == NULL) + break; + + if (op_expr[0]->operation == ir_unop_log2) { + return op_expr[0]->operands[0]; + } + + if (!options->EmitNoPow && op_expr[0]->operation == ir_binop_mul) { + for (int log2_pos = 0; log2_pos < 2; log2_pos++) { + ir_expression *log2_expr = + op_expr[0]->operands[log2_pos]->as_expression(); + + if (log2_expr && log2_expr->operation == ir_unop_log2) { + return new(mem_ctx) ir_expression(ir_binop_pow, + ir->type, + log2_expr->operands[0], + op_expr[0]->operands[1 - log2_pos]); + } + } + } + break; + + case ir_unop_log2: + if (op_expr[0] == NULL) + break; + + if (op_expr[0]->operation == ir_unop_exp2) { + return op_expr[0]->operands[0]; + } + break; + + case ir_unop_f2i: + case ir_unop_f2u: + if (op_expr[0] && op_expr[0]->operation == ir_unop_trunc) { + return new(mem_ctx) ir_expression(ir->operation, + ir->type, + op_expr[0]->operands[0]); + } + break; + + 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) { + return new(mem_ctx) ir_expression(new_op, + ir->type, + op_expr[0]->operands[0], + op_expr[0]->operands[1]); + } + + break; + } + + case ir_unop_saturate: + if (op_expr[0] && op_expr[0]->operation == ir_binop_add) { + ir_expression *b2f_0 = op_expr[0]->operands[0]->as_expression(); + ir_expression *b2f_1 = op_expr[0]->operands[1]->as_expression(); + + if (b2f_0 && b2f_0->operation == ir_unop_b2f && + b2f_1 && b2f_1->operation == ir_unop_b2f) { + return b2f(logic_or(b2f_0->operands[0], b2f_1->operands[0])); + } + } + break; + + case ir_binop_add: + if (is_vec_zero(op_const[0])) + return ir->operands[1]; + if (is_vec_zero(op_const[1])) + 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], op_expr[1]); + if (op_const[1] && !op_const[0]) + reassociate_constant(ir, 1, op_const[1], op_expr[0]); + + /* Recognize (v.x + v.y) + (v.z + v.w) as dot(v, 1.0) */ + if (options->OptimizeForAOS) { + ir_expression *expr = try_replace_with_dot(op_expr[0], op_expr[1], + mem_ctx); + if (expr) + return expr; + } + + /* Replace (-x + y) * a + x and commutative variations with lrp(x, y, a). + * + * (-x + y) * a + x + * (x * -a) + (y * a) + x + * x + (x * -a) + (y * a) + * x * (1 - a) + y * a + * lrp(x, y, a) + */ + for (int mul_pos = 0; mul_pos < 2; mul_pos++) { + ir_expression *mul = op_expr[mul_pos]; + + if (!mul || mul->operation != ir_binop_mul) + continue; + + /* Multiply found on one of the operands. Now check for an + * inner addition operation. + */ + for (int inner_add_pos = 0; inner_add_pos < 2; inner_add_pos++) { + ir_expression *inner_add = + mul->operands[inner_add_pos]->as_expression(); + + if (!inner_add || inner_add->operation != ir_binop_add) + continue; + + /* Inner addition found on one of the operands. Now check for + * one of the operands of the inner addition to be the negative + * of x_operand. + */ + for (int neg_pos = 0; neg_pos < 2; neg_pos++) { + ir_expression *neg = + inner_add->operands[neg_pos]->as_expression(); + + if (!neg || neg->operation != ir_unop_neg) + continue; + + ir_rvalue *x_operand = ir->operands[1 - mul_pos]; + + if (!neg->operands[0]->equals(x_operand)) + continue; + + ir_rvalue *y_operand = inner_add->operands[1 - neg_pos]; + ir_rvalue *a_operand = mul->operands[1 - inner_add_pos]; + + if (x_operand->type != y_operand->type || + x_operand->type != a_operand->type) + continue; + + return lrp(x_operand, y_operand, a_operand); + } + } + } + + break; + + case ir_binop_sub: + if (is_vec_zero(op_const[0])) + return neg(ir->operands[1]); + if (is_vec_zero(op_const[1])) + return ir->operands[0]; + break; + + case ir_binop_mul: + if (is_vec_one(op_const[0])) + return ir->operands[1]; + if (is_vec_one(op_const[1])) + return ir->operands[0]; + + if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) + return ir_constant::zero(ir, ir->type); + + if (is_vec_negative_one(op_const[0])) + return neg(ir->operands[1]); + if (is_vec_negative_one(op_const[1])) + return neg(ir->operands[0]); + + if (op_expr[0] && op_expr[0]->operation == ir_unop_b2f && + op_expr[1] && op_expr[1]->operation == ir_unop_b2f) { + return b2f(logic_and(op_expr[0]->operands[0], op_expr[1]->operands[0])); + } + + /* 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], op_expr[1]); + if (op_const[1] && !op_const[0]) + reassociate_constant(ir, 1, op_const[1], op_expr[0]); + + /* Optimizes + * + * (mul (floor (add (abs x) 0.5) (sign x))) + * + * into + * + * (trunc (add x (mul (sign x) 0.5))) + */ + for (int i = 0; i < 2; i++) { + ir_expression *sign_expr = ir->operands[i]->as_expression(); + ir_expression *floor_expr = ir->operands[1 - i]->as_expression(); + + if (!sign_expr || sign_expr->operation != ir_unop_sign || + !floor_expr || floor_expr->operation != ir_unop_floor) + continue; + + ir_expression *add_expr = floor_expr->operands[0]->as_expression(); + if (!add_expr || add_expr->operation != ir_binop_add) + continue; + + for (int j = 0; j < 2; j++) { + ir_expression *abs_expr = add_expr->operands[j]->as_expression(); + if (!abs_expr || abs_expr->operation != ir_unop_abs) + continue; + + ir_constant *point_five = add_expr->operands[1 - j]->as_constant(); + if (!point_five || !point_five->is_value(0.5, 0)) + continue; + + if (abs_expr->operands[0]->equals(sign_expr->operands[0])) { + return trunc(add(abs_expr->operands[0], + mul(sign_expr, point_five))); + } + } + } + break; + + case ir_binop_div: + if (is_vec_one(op_const[0]) && ( + ir->type->base_type == GLSL_TYPE_FLOAT || + ir->type->base_type == GLSL_TYPE_DOUBLE)) { + return new(mem_ctx) ir_expression(ir_unop_rcp, + ir->operands[1]->type, + ir->operands[1], + NULL); + } + if (is_vec_one(op_const[1])) + return ir->operands[0]; + break; + + case ir_binop_dot: + if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) + return ir_constant::zero(mem_ctx, ir->type); + + for (int i = 0; i < 2; i++) { + if (!op_const[i]) + continue; + + unsigned components[4] = { 0 }, count = 0; + + for (unsigned c = 0; c < op_const[i]->type->vector_elements; c++) { + if (op_const[i]->is_zero()) + continue; + + components[count] = c; + count++; + } + + /* No channels had zero values; bail. */ + if (count >= op_const[i]->type->vector_elements) + break; + + ir_expression_operation op = count == 1 ? + ir_binop_mul : ir_binop_dot; + + /* Swizzle both operands to remove the channels that were zero. */ + return new(mem_ctx) + ir_expression(op, ir->type, + new(mem_ctx) ir_swizzle(ir->operands[0], + components, count), + new(mem_ctx) ir_swizzle(ir->operands[1], + components, count)); + } + break; + + case ir_binop_less: + case ir_binop_lequal: + case ir_binop_greater: + case ir_binop_gequal: + case ir_binop_equal: + case ir_binop_nequal: + for (int add_pos = 0; add_pos < 2; add_pos++) { + ir_expression *add = op_expr[add_pos]; + + if (!add || add->operation != ir_binop_add) + continue; + + ir_constant *zero = op_const[1 - add_pos]; + if (!is_vec_zero(zero)) + continue; + + /* Depending of the zero position we want to optimize + * (0 cmp x+y) into (-x cmp y) or (x+y cmp 0) into (x cmp -y) + */ + if (add_pos == 1) { + return new(mem_ctx) ir_expression(ir->operation, + neg(add->operands[0]), + add->operands[1]); + } else { + return new(mem_ctx) ir_expression(ir->operation, + add->operands[0], + neg(add->operands[1])); + } + } + break; + + case ir_binop_all_equal: + case ir_binop_any_nequal: + if (ir->operands[0]->type->is_scalar() && + ir->operands[1]->type->is_scalar()) + return new(mem_ctx) ir_expression(ir->operation == ir_binop_all_equal + ? ir_binop_equal : ir_binop_nequal, + ir->operands[0], + ir->operands[1]); + break; + + case ir_binop_rshift: + case ir_binop_lshift: + /* 0 >> x == 0 */ + if (is_vec_zero(op_const[0])) + return ir->operands[0]; + /* x >> 0 == x */ + if (is_vec_zero(op_const[1])) + return ir->operands[0]; + break; + + case ir_binop_logic_and: + if (is_vec_one(op_const[0])) { + return ir->operands[1]; + } else if (is_vec_one(op_const[1])) { + return ir->operands[0]; + } else if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) { + return ir_constant::zero(mem_ctx, ir->type); + } else if (op_expr[0] && op_expr[0]->operation == ir_unop_logic_not && + op_expr[1] && op_expr[1]->operation == ir_unop_logic_not) { + /* De Morgan's Law: + * (not A) and (not B) === not (A or B) + */ + return logic_not(logic_or(op_expr[0]->operands[0], + op_expr[1]->operands[0])); + } else if (ir->operands[0]->equals(ir->operands[1])) { + /* (a && a) == a */ + return ir->operands[0]; + } + break; + + case ir_binop_logic_xor: + if (is_vec_zero(op_const[0])) { + return ir->operands[1]; + } else if (is_vec_zero(op_const[1])) { + return ir->operands[0]; + } else if (is_vec_one(op_const[0])) { + return logic_not(ir->operands[1]); + } else if (is_vec_one(op_const[1])) { + return logic_not(ir->operands[0]); + } else if (ir->operands[0]->equals(ir->operands[1])) { + /* (a ^^ a) == false */ + return ir_constant::zero(mem_ctx, ir->type); + } + break; + + case ir_binop_logic_or: + if (is_vec_zero(op_const[0])) { + return ir->operands[1]; + } else if (is_vec_zero(op_const[1])) { + 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; + + return new(mem_ctx) ir_constant(ir->type, &data); + } else if (op_expr[0] && op_expr[0]->operation == ir_unop_logic_not && + op_expr[1] && op_expr[1]->operation == ir_unop_logic_not) { + /* De Morgan's Law: + * (not A) or (not B) === not (A and B) + */ + return logic_not(logic_and(op_expr[0]->operands[0], + op_expr[1]->operands[0])); + } else if (ir->operands[0]->equals(ir->operands[1])) { + /* (a || a) == a */ + return ir->operands[0]; + } + break; + + case ir_binop_pow: + /* 1^x == 1 */ + if (is_vec_one(op_const[0])) + return op_const[0]; + + /* x^1 == x */ + if (is_vec_one(op_const[1])) + return ir->operands[0]; + + /* pow(2,x) == exp2(x) */ + if (is_vec_two(op_const[0])) + return expr(ir_unop_exp2, ir->operands[1]); + + if (is_vec_two(op_const[1])) { + ir_variable *x = new(ir) ir_variable(ir->operands[1]->type, "x", + ir_var_temporary); + base_ir->insert_before(x); + base_ir->insert_before(assign(x, ir->operands[0])); + return mul(x, x); + } + + if (is_vec_four(op_const[1])) { + ir_variable *x = new(ir) ir_variable(ir->operands[1]->type, "x", + ir_var_temporary); + base_ir->insert_before(x); + base_ir->insert_before(assign(x, ir->operands[0])); + + ir_variable *squared = new(ir) ir_variable(ir->operands[1]->type, + "squared", + ir_var_temporary); + base_ir->insert_before(squared); + base_ir->insert_before(assign(squared, mul(x, x))); + return mul(squared, squared); + } + + break; + + case ir_binop_min: + case ir_binop_max: + if (ir->type->base_type != GLSL_TYPE_FLOAT || options->EmitNoSat) + break; + + /* Replace min(max) operations and its commutative combinations with + * a saturate operation + */ + for (int op = 0; op < 2; op++) { + ir_expression *inner_expr = op_expr[op]; + ir_constant *outer_const = op_const[1 - op]; + ir_expression_operation op_cond = (ir->operation == ir_binop_max) ? + ir_binop_min : ir_binop_max; + + if (!inner_expr || !outer_const || (inner_expr->operation != op_cond)) + continue; + + /* One of these has to be a constant */ + if (!inner_expr->operands[0]->as_constant() && + !inner_expr->operands[1]->as_constant()) + break; + + /* Found a min(max) combination. Now try to see if its operands + * meet our conditions that we can do just a single saturate operation + */ + for (int minmax_op = 0; minmax_op < 2; minmax_op++) { + ir_rvalue *x = inner_expr->operands[minmax_op]; + ir_rvalue *y = inner_expr->operands[1 - minmax_op]; + + ir_constant *inner_const = y->as_constant(); + if (!inner_const) + continue; + + /* min(max(x, 0.0), 1.0) is sat(x) */ + if (ir->operation == ir_binop_min && + inner_const->is_zero() && + outer_const->is_one()) + return saturate(x); + + /* max(min(x, 1.0), 0.0) is sat(x) */ + if (ir->operation == ir_binop_max && + inner_const->is_one() && + outer_const->is_zero()) + return saturate(x); + + /* min(max(x, 0.0), b) where b < 1.0 is sat(min(x, b)) */ + if (ir->operation == ir_binop_min && + inner_const->is_zero() && + is_less_than_one(outer_const)) + return saturate(expr(ir_binop_min, x, outer_const)); + + /* max(min(x, b), 0.0) where b < 1.0 is sat(min(x, b)) */ + if (ir->operation == ir_binop_max && + is_less_than_one(inner_const) && + outer_const->is_zero()) + return saturate(expr(ir_binop_min, x, inner_const)); + + /* max(min(x, 1.0), b) where b > 0.0 is sat(max(x, b)) */ + if (ir->operation == ir_binop_max && + inner_const->is_one() && + is_greater_than_zero(outer_const)) + return saturate(expr(ir_binop_max, x, outer_const)); + + /* min(max(x, b), 1.0) where b > 0.0 is sat(max(x, b)) */ + if (ir->operation == ir_binop_min && + is_greater_than_zero(inner_const) && + outer_const->is_one()) + return saturate(expr(ir_binop_max, x, inner_const)); + } + } + + break; + + case ir_unop_rcp: + if (op_expr[0] && op_expr[0]->operation == ir_unop_rcp) + return op_expr[0]->operands[0]; + + if (op_expr[0] && (op_expr[0]->operation == ir_unop_exp2 || + op_expr[0]->operation == ir_unop_exp)) { + return new(mem_ctx) ir_expression(op_expr[0]->operation, ir->type, + neg(op_expr[0]->operands[0])); + } + + /* While ir_to_mesa.cpp will lower sqrt(x) to rcp(rsq(x)), it does so at + * its IR level, so we can always apply this transformation. + */ + if (op_expr[0] && op_expr[0]->operation == ir_unop_rsq) + return sqrt(op_expr[0]->operands[0]); + + /* As far as we know, all backends are OK with rsq. */ + if (op_expr[0] && op_expr[0]->operation == ir_unop_sqrt) { + return rsq(op_expr[0]->operands[0]); + } + + break; + + case ir_triop_fma: + /* Operands are op0 * op1 + op2. */ + if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) { + return ir->operands[2]; + } else if (is_vec_zero(op_const[2])) { + return mul(ir->operands[0], ir->operands[1]); + } else if (is_vec_one(op_const[0])) { + return add(ir->operands[1], ir->operands[2]); + } else if (is_vec_one(op_const[1])) { + return add(ir->operands[0], ir->operands[2]); + } + break; + + case ir_triop_lrp: + /* Operands are (x, y, a). */ + if (is_vec_zero(op_const[2])) { + return ir->operands[0]; + } else if (is_vec_one(op_const[2])) { + return ir->operands[1]; + } else if (ir->operands[0]->equals(ir->operands[1])) { + return ir->operands[0]; + } else if (is_vec_zero(op_const[0])) { + return mul(ir->operands[1], ir->operands[2]); + } else if (is_vec_zero(op_const[1])) { + unsigned op2_components = ir->operands[2]->type->vector_elements; + ir_constant *one; + + switch (ir->type->base_type) { + case GLSL_TYPE_FLOAT: + one = new(mem_ctx) ir_constant(1.0f, op2_components); + break; + case GLSL_TYPE_DOUBLE: + one = new(mem_ctx) ir_constant(1.0, op2_components); + break; + default: + one = NULL; + unreachable("unexpected type"); + } + + return mul(ir->operands[0], add(one, neg(ir->operands[2]))); + } + break; + + case ir_triop_csel: + if (is_vec_one(op_const[0])) + return ir->operands[1]; + if (is_vec_zero(op_const[0])) + return ir->operands[2]; + 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 || expr->operation == ir_quadop_vector) + return; + + ir_rvalue *new_rvalue = handle_expression(expr); + if (new_rvalue == *rvalue) + return; + + /* If the expr used to be some vec OP scalar returning a vector, and the + * optimization gave us back a scalar, we still need to turn it into a + * vector. + */ + *rvalue = swizzle_if_required(expr, new_rvalue); + + this->progress = true; +} + +bool +do_algebraic(exec_list *instructions, bool native_integers, + const struct gl_shader_compiler_options *options) +{ + ir_algebraic_visitor v(native_integers, options); + + visit_list_elements(&v, instructions); + + return v.progress; +} |