diff options
| -rw-r--r-- | src/compiler/glsl/opt_function_inlining.cpp | 91 |
1 files changed, 81 insertions, 10 deletions
diff --git a/src/compiler/glsl/opt_function_inlining.cpp b/src/compiler/glsl/opt_function_inlining.cpp index 83534bfaf9e..62c1f4b6fc2 100644 --- a/src/compiler/glsl/opt_function_inlining.cpp +++ b/src/compiler/glsl/opt_function_inlining.cpp @@ -62,6 +62,11 @@ public: bool progress; }; +class ir_save_lvalue_visitor : public ir_hierarchical_visitor { +public: + virtual ir_visitor_status visit_enter(ir_dereference_array *); +}; + } /* unnamed namespace */ bool @@ -95,6 +100,37 @@ replace_return_with_assignment(ir_instruction *ir, void *data) } } +/* Save the given lvalue before the given instruction. + * + * This is done by adding temporary variables into which the current value + * of any array indices are saved, and then modifying the dereference chain + * in-place to point to those temporary variables. + * + * The hierarchical visitor is only used to traverse the left-hand-side chain + * of derefs. + */ +ir_visitor_status +ir_save_lvalue_visitor::visit_enter(ir_dereference_array *deref) +{ + if (deref->array_index->ir_type != ir_type_constant) { + void *ctx = ralloc_parent(deref); + ir_variable *index; + ir_assignment *assignment; + + index = new(ctx) ir_variable(deref->array_index->type, "saved_idx", ir_var_temporary); + base_ir->insert_before(index); + + assignment = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(index), + deref->array_index, 0); + base_ir->insert_before(assignment); + + deref->array_index = new(ctx) ir_dereference_variable(index); + } + + deref->array->accept(this); + return visit_stop; +} + void ir_call::generate_inline(ir_instruction *next_ir) { @@ -139,15 +175,50 @@ ir_call::generate_inline(ir_instruction *next_ir) next_ir->insert_before(parameters[i]); } - /* Move the actual param into our param variable if it's an 'in' type. */ - if (parameters[i] && (sig_param->data.mode == ir_var_function_in || - sig_param->data.mode == ir_var_const_in || - sig_param->data.mode == ir_var_function_inout)) { - ir_assignment *assign; - - assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(parameters[i]), - param, NULL); - next_ir->insert_before(assign); + /* Section 6.1.1 (Function Calling Conventions) of the OpenGL Shading + * Language 4.5 spec says: + * + * "All arguments are evaluated at call time, exactly once, in order, + * from left to right. [...] Evaluation of an out parameter results + * in an l-value that is used to copy out a value when the function + * returns." + * + * I.e., we have to take temporary copies of any relevant array indices + * before the function body is executed. + * + * This ensures that + * (a) if an array index expressions refers to a variable that is + * modified by the execution of the function body, we use the + * original value as intended, and + * (b) if an array index expression has side effects, those side effects + * are only executed once and at the right time. + */ + if (parameters[i]) { + if (sig_param->data.mode == ir_var_function_in || + sig_param->data.mode == ir_var_const_in) { + ir_assignment *assign; + + assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(parameters[i]), + param, NULL); + next_ir->insert_before(assign); + } else { + assert(sig_param->data.mode == ir_var_function_out || + sig_param->data.mode == ir_var_function_inout); + assert(param->is_lvalue()); + + ir_save_lvalue_visitor v; + v.base_ir = next_ir; + + param->accept(&v); + + if (sig_param->data.mode == ir_var_function_inout) { + ir_assignment *assign; + + assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(parameters[i]), + param->clone(ctx, NULL)->as_rvalue(), NULL); + next_ir->insert_before(assign); + } + } } ++i; @@ -196,7 +267,7 @@ ir_call::generate_inline(ir_instruction *next_ir) sig_param->data.mode == ir_var_function_inout)) { ir_assignment *assign; - assign = new(ctx) ir_assignment(param->clone(ctx, NULL)->as_rvalue(), + assign = new(ctx) ir_assignment(param, new(ctx) ir_dereference_variable(parameters[i]), NULL); next_ir->insert_before(assign); |