diff options
| -rw-r--r-- | src/glsl/opt_constant_propagation.cpp | 45 |
1 files changed, 43 insertions, 2 deletions
diff --git a/src/glsl/opt_constant_propagation.cpp b/src/glsl/opt_constant_propagation.cpp index 10be8e800ff..5221417aca0 100644 --- a/src/glsl/opt_constant_propagation.cpp +++ b/src/glsl/opt_constant_propagation.cpp @@ -110,6 +110,8 @@ public: virtual ir_visitor_status visit_enter(class ir_if *); void add_constant(ir_assignment *ir); + void constant_folding(ir_rvalue **rvalue); + void constant_propagation(ir_rvalue **rvalue); void kill(ir_variable *ir, unsigned write_mask); void handle_if_block(exec_list *instructions); void handle_rvalue(ir_rvalue **rvalue); @@ -132,8 +134,38 @@ public: void -ir_constant_propagation_visitor::handle_rvalue(ir_rvalue **rvalue) -{ +ir_constant_propagation_visitor::constant_folding(ir_rvalue **rvalue) { + + if (*rvalue == NULL || (*rvalue)->ir_type == ir_type_constant) + return; + + /* Note that we visit rvalues one leaving. So if an expression has a + * non-constant operand, no need to go looking down it to find if it's + * constant. This cuts the time of this pass down drastically. + */ + ir_expression *expr = (*rvalue)->as_expression(); + if (expr) { + for (unsigned int i = 0; i < expr->get_num_operands(); i++) { + if (!expr->operands[i]->as_constant()) + return; + } + } + + /* Ditto for swizzles. */ + ir_swizzle *swiz = (*rvalue)->as_swizzle(); + if (swiz && !swiz->val->as_constant()) + return; + + ir_constant *constant = (*rvalue)->constant_expression_value(); + if (constant) { + *rvalue = constant; + this->progress = true; + } +} + +void +ir_constant_propagation_visitor::constant_propagation(ir_rvalue **rvalue) { + if (this->in_assignee || !*rvalue) return; @@ -216,6 +248,13 @@ ir_constant_propagation_visitor::handle_rvalue(ir_rvalue **rvalue) this->progress = true; } +void +ir_constant_propagation_visitor::handle_rvalue(ir_rvalue **rvalue) +{ + constant_propagation(rvalue); + constant_folding(rvalue); +} + ir_visitor_status ir_constant_propagation_visitor::visit_enter(ir_function_signature *ir) { @@ -243,6 +282,8 @@ ir_constant_propagation_visitor::visit_enter(ir_function_signature *ir) ir_visitor_status ir_constant_propagation_visitor::visit_leave(ir_assignment *ir) { + constant_folding(&ir->rhs); + if (this->in_assignee) return visit_continue; |