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Diffstat (limited to 'src/glsl/lower_vector.cpp')
| -rw-r--r-- | src/glsl/lower_vector.cpp | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/src/glsl/lower_vector.cpp b/src/glsl/lower_vector.cpp new file mode 100644 index 00000000000..93c37638bbd --- /dev/null +++ b/src/glsl/lower_vector.cpp @@ -0,0 +1,224 @@ +/* + * 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 lower_vector.cpp + * IR lowering pass to remove some types of ir_quadop_vector + * + * \author Ian Romanick <[email protected]> + */ + +#include "ir.h" +#include "ir_rvalue_visitor.h" + +class lower_vector_visitor : public ir_rvalue_visitor { +public: + lower_vector_visitor() : progress(false) + { + /* empty */ + } + + void handle_rvalue(ir_rvalue **rvalue); + + /** + * Should SWZ-like expressions be lowered? + */ + bool dont_lower_swz; + + bool progress; +}; + +/** + * Determine if an IR expression tree looks like an extended swizzle + * + * Extended swizzles consist of access of a single vector source (with possible + * per component negation) and the constants -1, 0, or 1. + */ +bool +is_extended_swizzle(ir_expression *ir) +{ + /* Track any variables that are accessed by this expression. + */ + ir_variable *var = NULL; + + assert(ir->operation == ir_quadop_vector); + + for (unsigned i = 0; i < ir->type->vector_elements; i++) { + ir_rvalue *op = ir->operands[i]; + + while (op != NULL) { + switch (op->ir_type) { + case ir_type_constant: { + const ir_constant *const c = op->as_constant(); + + if (!c->is_one() && !c->is_zero() && !c->is_negative_one()) + return false; + + op = NULL; + break; + } + + case ir_type_dereference_variable: { + ir_dereference_variable *const d = (ir_dereference_variable *) op; + + if ((var != NULL) && (var != d->var)) + return false; + + var = d->var; + op = NULL; + break; + } + + case ir_type_expression: { + ir_expression *const ex = (ir_expression *) op; + + if (ex->operation != ir_unop_neg) + return false; + + op = ex->operands[0]; + break; + } + + case ir_type_swizzle: + op = ((ir_swizzle *) op)->val; + break; + + default: + return false; + } + } + } + + return true; +} + +void +lower_vector_visitor::handle_rvalue(ir_rvalue **rvalue) +{ + if (!*rvalue) + return; + + ir_expression *expr = (*rvalue)->as_expression(); + if ((expr == NULL) || (expr->operation != ir_quadop_vector)) + return; + + if (this->dont_lower_swz && is_extended_swizzle(expr)) + return; + + /* FINISHME: Is this the right thing to use for the talloc context? + */ + void *const mem_ctx = expr; + + assert(expr->type->vector_elements == expr->get_num_operands()); + + /* Generate a temporary with the same type as the ir_quadop_operation. + */ + ir_variable *const temp = + new(mem_ctx) ir_variable(expr->type, "vecop_tmp", ir_var_temporary); + + this->base_ir->insert_before(temp); + + /* Counter of the number of components collected so far. + */ + unsigned assigned; + + /* Write-mask in the destination that receives counted by 'assigned'. + */ + unsigned write_mask; + + + /* Generate upto four assignments to that variable. Try to group component + * assignments together: + * + * - All constant components can be assigned at once. + * - All assigments of components from a single variable with the same + * unary operator can be assigned at once. + */ + ir_constant_data d = { { 0 } }; + + assigned = 0; + write_mask = 0; + for (unsigned i = 0; i < expr->type->vector_elements; i++) { + const ir_constant *const c = expr->operands[i]->as_constant(); + + if (c == NULL) + continue; + + switch (expr->type->base_type) { + case GLSL_TYPE_UINT: d.u[assigned] = c->value.u[0]; break; + case GLSL_TYPE_INT: d.i[assigned] = c->value.i[0]; break; + case GLSL_TYPE_FLOAT: d.f[assigned] = c->value.f[0]; break; + case GLSL_TYPE_BOOL: d.b[assigned] = c->value.b[0]; break; + default: assert(!"Should not get here."); break; + } + + write_mask |= (1U << i); + assigned++; + } + + assert((write_mask == 0) == (assigned == 0)); + + /* If there were constant values, generate an assignment. + */ + if (assigned > 0) { + ir_constant *const c = + new(mem_ctx) ir_constant(glsl_type::get_instance(expr->type->base_type, + assigned, 0), + &d); + ir_dereference *const lhs = new(mem_ctx) ir_dereference_variable(temp); + ir_assignment *const assign = + new(mem_ctx) ir_assignment(lhs, c, NULL, write_mask); + + this->base_ir->insert_before(assign); + } + + /* FINISHME: This should try to coalesce assignments. + */ + for (unsigned i = 0; i < expr->type->vector_elements; i++) { + if (expr->operands[i]->ir_type == ir_type_constant) + continue; + + ir_dereference *const lhs = new(mem_ctx) ir_dereference_variable(temp); + ir_assignment *const assign = + new(mem_ctx) ir_assignment(lhs, expr->operands[i], NULL, (1U << i)); + + this->base_ir->insert_before(assign); + assigned++; + } + + assert(assigned == expr->type->vector_elements); + + *rvalue = new(mem_ctx) ir_dereference_variable(temp); + this->progress = true; +} + +bool +lower_quadop_vector(exec_list *instructions, bool dont_lower_swz) +{ + lower_vector_visitor v; + + v.dont_lower_swz = dont_lower_swz; + visit_list_elements(&v, instructions); + + return v.progress; +} |