From: Brian Paul Date: Fri, 26 Jun 2009 17:33:05 +0000 (-0600) Subject: glsl: overhaul 'return' statement handling X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8e6dd8bf7991d8fc4938af692e5ce880ef139b4d;p=mesa.git glsl: overhaul 'return' statement handling A new node type (SLANG_OPER_RETURN_INLINED) is used to denote 'return' statements inside inlined functions which need special handling. All glean glsl1 tests pass for EmitContReturn=FALSE and TRUE. --- diff --git a/src/mesa/shader/slang/slang_codegen.c b/src/mesa/shader/slang/slang_codegen.c index 6aa18868c0b..28d04d396db 100644 --- a/src/mesa/shader/slang/slang_codegen.c +++ b/src/mesa/shader/slang/slang_codegen.c @@ -818,6 +818,7 @@ _slang_is_noop(const slang_operation *oper) /** * Recursively search tree for a node of the given type. */ +#if 0 static slang_operation * _slang_find_node_type(slang_operation *oper, slang_operation_type type) { @@ -831,6 +832,7 @@ _slang_find_node_type(slang_operation *oper, slang_operation_type type) } return NULL; } +#endif /** @@ -932,41 +934,43 @@ slang_resolve_variable(slang_operation *oper) /** - * Generate code for "return expr;" + * Rewrite AST code for "return expression;". + * * We return values from functions by assinging the returned value to * the hidden __retVal variable which is an extra 'out' parameter we add * to the function signature. * This code basically converts "return expr;" into "__retVal = expr; return;" + * * \return the new AST code. */ static slang_operation * -gen_return_expression(slang_assemble_ctx *A, slang_operation *oper) +gen_return_with_expression(slang_assemble_ctx *A, slang_operation *oper) { - slang_operation *blockOper; + slang_operation *blockOper, *assignOper; + + assert(oper->type == SLANG_OPER_RETURN); blockOper = slang_operation_new(1); blockOper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE; blockOper->locals->outer_scope = oper->locals->outer_scope; slang_operation_add_children(blockOper, 2); - /* if EmitContReturn: - * if (!__returnFlag) { - * build: __retVal = expr; - * } - * otherwise: - * build: __retVal = expr; - */ - { - slang_operation *assignOper; - - if (A->UseReturnFlag) { + if (A->UseReturnFlag) { + /* Emit: + * { + * if (__notRetFlag) + * __retVal = expr; + * __notRetFlag = 0; + * } + */ + { slang_operation *ifOper = slang_oper_child(blockOper, 0); ifOper->type = SLANG_OPER_IF; slang_operation_add_children(ifOper, 3); { slang_operation *cond = slang_oper_child(ifOper, 0); cond->type = SLANG_OPER_IDENTIFIER; - cond->a_id = slang_atom_pool_atom(A->atoms, "__returnFlag"); + cond->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag"); } { slang_operation *elseOper = slang_oper_child(ifOper, 2); @@ -974,34 +978,103 @@ gen_return_expression(slang_assemble_ctx *A, slang_operation *oper) } assignOper = slang_oper_child(ifOper, 1); } - else { - assignOper = slang_oper_child(blockOper, 0); - } - - assignOper->type = SLANG_OPER_ASSIGN; - slang_operation_add_children(assignOper, 2); { - slang_operation *lhs = slang_oper_child(assignOper, 0); - lhs->type = SLANG_OPER_IDENTIFIER; - lhs->a_id = slang_atom_pool_atom(A->atoms, "__retVal"); + slang_operation *setOper = slang_oper_child(blockOper, 1); + setOper->type = SLANG_OPER_ASSIGN; + slang_operation_add_children(setOper, 2); + { + slang_operation *lhs = slang_oper_child(setOper, 0); + lhs->type = SLANG_OPER_IDENTIFIER; + lhs->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag"); + } + { + slang_operation *rhs = slang_oper_child(setOper, 1); + slang_operation_literal_bool(rhs, GL_FALSE); + } } + } + else { + /* Emit: + * { + * __retVal = expr; + * return_inlined; + * } + */ + assignOper = slang_oper_child(blockOper, 0); { - slang_operation *rhs = slang_oper_child(assignOper, 1); - slang_operation_copy(rhs, &oper->children[0]); + slang_operation *returnOper = slang_oper_child(blockOper, 1); + returnOper->type = SLANG_OPER_RETURN_INLINED; + assert(returnOper->num_children == 0); } } - /* build: return; (with no return value) */ + /* __retVal = expression; */ + assignOper->type = SLANG_OPER_ASSIGN; + slang_operation_add_children(assignOper, 2); + { + slang_operation *lhs = slang_oper_child(assignOper, 0); + lhs->type = SLANG_OPER_IDENTIFIER; + lhs->a_id = slang_atom_pool_atom(A->atoms, "__retVal"); + } { - slang_operation *returnOper = slang_oper_child(blockOper, 1); - returnOper->type = SLANG_OPER_RETURN; /* return w/ no value */ - assert(returnOper->num_children == 0); + slang_operation *rhs = slang_oper_child(assignOper, 1); + slang_operation_copy(rhs, &oper->children[0]); } + ///blockOper->locals->outer_scope = oper->locals->outer_scope; + + /*slang_print_tree(blockOper, 0);*/ + return blockOper; } +/** + * Rewrite AST code for "return;" (no expression). + */ +static slang_operation * +gen_return_without_expression(slang_assemble_ctx *A, slang_operation *oper) +{ + slang_operation *newRet; + + assert(oper->type == SLANG_OPER_RETURN); + + if (A->UseReturnFlag) { + /* Emit: + * __notRetFlag = 0; + */ + { + newRet = slang_operation_new(1); + newRet->locals->outer_scope = oper->locals->outer_scope; + newRet->type = SLANG_OPER_ASSIGN; + slang_operation_add_children(newRet, 2); + { + slang_operation *lhs = slang_oper_child(newRet, 0); + lhs->type = SLANG_OPER_IDENTIFIER; + lhs->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag"); + } + { + slang_operation *rhs = slang_oper_child(newRet, 1); + slang_operation_literal_bool(rhs, GL_FALSE); + } + } + } + else { + /* Emit: + * return_inlined; + */ + newRet = slang_operation_new(1); + newRet->locals->outer_scope = oper->locals->outer_scope; + newRet->type = SLANG_OPER_RETURN_INLINED; + } + + /*slang_print_tree(newRet, 0);*/ + + return newRet; +} + + + /** * Replace particular variables (SLANG_OPER_IDENTIFIER) with new expressions. @@ -1038,7 +1111,7 @@ slang_substitute(slang_assemble_ctx *A, slang_operation *oper, GLuint i; v = _slang_variable_locate(oper->locals, id, GL_TRUE); if (!v) { - if (_mesa_strcmp((char *) oper->a_id, "__returnFlag")) + if (_mesa_strcmp((char *) oper->a_id, "__notRetFlag")) _mesa_problem(NULL, "var %s not found!\n", (char *) oper->a_id); return; } @@ -1069,37 +1142,22 @@ slang_substitute(slang_assemble_ctx *A, slang_operation *oper, break; case SLANG_OPER_RETURN: - /* do return replacement here too */ - assert(oper->num_children == 0 || oper->num_children == 1); - if (oper->num_children == 1 && !_slang_is_noop(&oper->children[0])) { + { slang_operation *newReturn; - - /* check if function actually has a return type */ - assert(A->CurFunction); - if (A->CurFunction->header.type.specifier.type == SLANG_SPEC_VOID) { - slang_info_log_error(A->log, "illegal return expression"); - return; - } - /* generate new 'return' code' */ - newReturn = gen_return_expression(A, oper); + if (slang_oper_child(oper, 0)->type == SLANG_OPER_VOID) + newReturn = gen_return_without_expression(A, oper); + else + newReturn = gen_return_with_expression(A, oper); - /* do substitutions on the "__retVal = expr" sub-tree */ - slang_substitute(A, slang_oper_child(newReturn, 0), + /* do substitutions on the new 'return' code */ + slang_substitute(A, newReturn, substCount, substOld, substNew, GL_FALSE); /* install new 'return' code */ slang_operation_copy(oper, newReturn); slang_operation_destruct(newReturn); } - else { - /* check if return value was expected */ - assert(A->CurFunction); - if (A->CurFunction->header.type.specifier.type != SLANG_SPEC_VOID) { - slang_info_log_error(A->log, "return statement requires an expression"); - return; - } - } break; case SLANG_OPER_ASSIGN: @@ -1494,7 +1552,7 @@ slang_inline_function_call(slang_assemble_ctx * A, slang_function *fun, /** - * Insert declaration for "bool __returnFlag" in given block operation. + * Insert declaration for "bool __notRetFlag" in given block operation. * This is used when we can't emit "early" return statements in subroutines. */ static void @@ -1508,44 +1566,31 @@ declare_return_flag(slang_assemble_ctx *A, slang_operation *oper) decl = slang_operation_insert_child(oper, 1); slang_generate_declaration(A, oper->locals, decl, - SLANG_SPEC_BOOL, "__returnFlag", GL_TRUE); + SLANG_SPEC_BOOL, "__notRetFlag", GL_TRUE); /*slang_print_tree(oper, 0);*/ } /** - * Replace 'return' with '__returnFlag = false'. - * This is used to remove 'early returns' from functions. + * Recursively replace instances of the old node type with the new type. */ static void -replace_return_with_flag_set(slang_assemble_ctx *A, slang_operation *oper) +replace_node_type(slang_operation *oper, slang_operation_type oldType, + slang_operation_type newType) { - slang_atom id = slang_atom_pool_atom(A->atoms, "__returnFlag"); - assert(oper->type == SLANG_OPER_RETURN); + GLuint i; - /* replace 'return' with __returnFlag = false' */ - slang_operation_free_children(oper); - oper->type = SLANG_OPER_ASSIGN; - slang_operation_add_children(oper, 2); - { - slang_operation *lhs = slang_oper_child(oper, 0); - lhs->type = SLANG_OPER_IDENTIFIER; - lhs->a_id = id; - } - { - slang_operation *rhs = slang_oper_child(oper, 1); - slang_operation_literal_bool(rhs, GL_FALSE); - } + if (oper->type == oldType) + oper->type = newType; - { - slang_variable *var; - var = _slang_variable_locate(oper->locals, id, GL_TRUE); - assert(var); + for (i = 0; i < slang_oper_num_children(oper); i++) { + replace_node_type(slang_oper_child(oper, i), oldType, newType); } } + /** * Test if the given function body has an "early return". That is, there's * a 'return' statement that's not the very last instruction in the body. @@ -1573,7 +1618,7 @@ _slang_gen_function_call(slang_assemble_ctx *A, slang_function *fun, slang_operation *oper, slang_operation *dest) { slang_ir_node *n; - slang_operation *inlined; + slang_operation *instance; slang_label *prevFuncEndLabel; char name[200]; @@ -1582,9 +1627,14 @@ _slang_gen_function_call(slang_assemble_ctx *A, slang_function *fun, A->curFuncEndLabel = _slang_label_new(name); assert(A->curFuncEndLabel); + /* + * 'instance' is basically a copy of the function's body with various + * transformations. + */ + if (slang_is_asm_function(fun) && !dest) { /* assemble assembly function - tree style */ - inlined = slang_inline_asm_function(A, fun, oper); + instance = slang_inline_asm_function(A, fun, oper); } else { /* non-assembly function */ @@ -1594,73 +1644,81 @@ _slang_gen_function_call(slang_assemble_ctx *A, slang_function *fun, * 2. Generate a call to the "inline" code as a subroutine */ const GLboolean earlyReturn = has_early_return(fun->body); - slang_operation *ret = NULL; if (earlyReturn && !A->EmitContReturn) { A->UseReturnFlag = GL_TRUE; } - inlined = slang_inline_function_call(A, fun, oper, dest); - if (!inlined) + instance = slang_inline_function_call(A, fun, oper, dest); + if (!instance) return NULL; - ret = _slang_find_node_type(inlined, SLANG_OPER_RETURN); - if (ret) { - /* check if this is a "tail" return */ - if (!earlyReturn) { - /* The only RETURN is the last stmt in the function, no-op it - * and inline the function body. + if (earlyReturn) { + /* The function we're calling has one or more 'return' statements + * that prevent us from inlining the function's code. + * + * In this case, change the function's body type from + * SLANG_OPER_BLOCK_NEW_SCOPE to SLANG_OPER_NON_INLINED_CALL. + * During code emit this will result in a true subroutine call. + * + * Also, convert SLANG_OPER_RETURN_INLINED nodes to SLANG_OPER_RETURN. + */ + slang_operation *callOper; + + assert(instance->type == SLANG_OPER_BLOCK_NEW_SCOPE || + instance->type == SLANG_OPER_SEQUENCE); + + if (_slang_function_has_return_value(fun) && !dest) { + assert(instance->children[0].type == SLANG_OPER_VARIABLE_DECL); + assert(instance->children[2].type == SLANG_OPER_IDENTIFIER); + callOper = &instance->children[1]; + } + else { + callOper = instance; + } + + if (A->UseReturnFlag) { + /* Early returns not supported. Create a _returnFlag variable + * that's set upon 'return' and tested elsewhere to no-op any + * remaining instructions in the subroutine. */ - ret->type = SLANG_OPER_NONE; + assert(callOper->type == SLANG_OPER_BLOCK_NEW_SCOPE || + callOper->type == SLANG_OPER_SEQUENCE); + declare_return_flag(A, callOper); } else { - slang_operation *callOper; - /* The function we're calling has one or more 'return' statements. - * So, we can't truly inline this function because we need to - * implement 'return' with RET (and CAL). - * Nevertheless, we performed "inlining" to make a new instance - * of the function body to deal with static register allocation. + /* We can emit real 'return' statements. If we generated any + * 'inline return' statements during function instantiation, + * change them back to regular 'return' statements. */ - assert(inlined->type == SLANG_OPER_BLOCK_NEW_SCOPE || - inlined->type == SLANG_OPER_SEQUENCE); - - if (_slang_function_has_return_value(fun) && !dest) { - assert(inlined->children[0].type == SLANG_OPER_VARIABLE_DECL); - assert(inlined->children[2].type == SLANG_OPER_IDENTIFIER); - callOper = &inlined->children[1]; - } - else { - callOper = inlined; - } - - if (A->UseReturnFlag) { - /* Early returns not supported. Create a _returnFlag variable - * that's set upon 'return' and tested elsewhere to no-op any - * remaining instructions in the subroutine. - */ - assert(callOper->type == SLANG_OPER_BLOCK_NEW_SCOPE || - callOper->type == SLANG_OPER_SEQUENCE); - declare_return_flag(A, callOper); - } - callOper->type = SLANG_OPER_NON_INLINED_CALL; - callOper->fun = fun; - callOper->label = _slang_label_new_unique((char*) fun->header.a_name); + replace_node_type(instance, SLANG_OPER_RETURN_INLINED, + SLANG_OPER_RETURN); } + + callOper->type = SLANG_OPER_NON_INLINED_CALL; + callOper->fun = fun; + callOper->label = _slang_label_new_unique((char*) fun->header.a_name); + } + else { + /* If there are any 'return' statements remaining, they're at the + * very end of the function and can effectively become no-ops. + */ + replace_node_type(instance, SLANG_OPER_RETURN_INLINED, + SLANG_OPER_VOID); } } - if (!inlined) + if (!instance) return NULL; - /* Replace the function call with the inlined block (or new CALL stmt) */ + /* Replace the function call with the instance block (or new CALL stmt) */ slang_operation_destruct(oper); - *oper = *inlined; - _slang_free(inlined); + *oper = *instance; + _slang_free(instance); #if 0 - assert(inlined->locals); - printf("*** Inlined code for call to %s:\n", - (char*) fun->header.a_name); + assert(instance->locals); + printf("*** Inlined code for call to %s:\n", (char*) fun->header.a_name); slang_print_tree(oper, 10); printf("\n"); #endif @@ -4005,98 +4063,26 @@ _slang_gen_return(slang_assemble_ctx * A, slang_operation *oper) const GLboolean haveReturnValue = (oper->num_children == 1 && oper->children[0].type != SLANG_OPER_VOID); - assert(oper->type == SLANG_OPER_RETURN); + assert(oper->type == SLANG_OPER_RETURN || + oper->type == SLANG_OPER_RETURN_INLINED); /* error checking */ - assert(A->CurFunction); - if (haveReturnValue && - A->CurFunction->header.type.specifier.type == SLANG_SPEC_VOID) { - slang_info_log_error(A->log, "illegal return expression"); - return NULL; - } - else if (!haveReturnValue && - A->CurFunction->header.type.specifier.type != SLANG_SPEC_VOID) { - slang_info_log_error(A->log, "return statement requires an expression"); - return NULL; - } + if (oper->type == SLANG_OPER_RETURN) { + assert(A->CurFunction); - if (!haveReturnValue) { - if (A->EmitContReturn) { - return new_return(A->curFuncEndLabel); + if (haveReturnValue && + A->CurFunction->header.type.specifier.type == SLANG_SPEC_VOID) { + slang_info_log_error(A->log, "illegal return expression"); + return NULL; } - else { - replace_return_with_flag_set(A, oper); - return _slang_gen_operation(A, oper); + else if (!haveReturnValue && + A->CurFunction->header.type.specifier.type != SLANG_SPEC_VOID) { + slang_info_log_error(A->log, "return statement requires an expression"); + return NULL; } } - else { - /* - * Convert from: - * return expr; - * To: - * __retVal = expr; - * return; // goto __endOfFunction - */ - slang_operation *assign; - slang_atom a_retVal; - slang_ir_node *n; - - a_retVal = slang_atom_pool_atom(A->atoms, "__retVal"); - assert(a_retVal); - -#if 1 /* DEBUG */ - { - slang_variable *v = - _slang_variable_locate(oper->locals, a_retVal, GL_TRUE); - if (!v) { - /* trying to return a value in a void-valued function */ - return NULL; - } - } -#endif - - /* XXX use the gen_return_expression() function here */ - - assign = slang_operation_new(1); - assign->type = SLANG_OPER_ASSIGN; - assign->num_children = 2; - assign->children = slang_operation_new(2); - /* lhs (__retVal) */ - assign->children[0].type = SLANG_OPER_IDENTIFIER; - assign->children[0].a_id = a_retVal; - assign->children[0].locals->outer_scope = assign->locals; - /* rhs (expr) */ - /* XXX we might be able to avoid this copy someday */ - slang_operation_copy(&assign->children[1], &oper->children[0]); - - /* assemble the new code */ - if (A->EmitContReturn) { - n = new_seq(_slang_gen_operation(A, assign), - new_return(A->curFuncEndLabel)); - } - else if (A->UseReturnFlag) { - /* set __returnFlag = false; */ - slang_operation *setFlag = slang_operation_new(1); - setFlag->type = SLANG_OPER_ASSIGN; - setFlag->locals->outer_scope = oper->locals; - slang_operation_add_children(setFlag, 2); - { - slang_operation *lhs = slang_oper_child(setFlag, 0); - lhs->type = SLANG_OPER_IDENTIFIER; - lhs->a_id = slang_atom_pool_atom(A->atoms, "__returnFlag"); - } - { - slang_operation *rhs = slang_oper_child(setFlag, 1); - slang_operation_literal_bool(rhs, GL_FALSE); - } - n = new_seq(_slang_gen_operation(A, assign), - _slang_gen_operation(A, setFlag)); - slang_operation_delete(setFlag); - } - slang_operation_delete(assign); - return n; - } + return new_return(A->curFuncEndLabel); } @@ -4382,14 +4368,14 @@ _slang_gen_assignment(slang_assemble_ctx * A, slang_operation *oper) return NULL; } - /* check if we need to predicate this assignment based on __returnFlag */ + /* check if we need to predicate this assignment based on __notRetFlag */ if ((var->is_global || var->type.qualifier == SLANG_QUAL_OUT || var->type.qualifier == SLANG_QUAL_INOUT) && A->UseReturnFlag) { /* create predicate, used below */ pred = slang_operation_new(1); pred->type = SLANG_OPER_IDENTIFIER; - pred->a_id = slang_atom_pool_atom(A->atoms, "__returnFlag"); + pred->a_id = slang_atom_pool_atom(A->atoms, "__notRetFlag"); pred->locals->outer_scope = oper->locals->outer_scope; } } @@ -4455,7 +4441,7 @@ _slang_gen_assignment(slang_assemble_ctx * A, slang_operation *oper) } if (n && pred) { - /* predicate the assignment code on __returnFlag */ + /* predicate the assignment code on __notRetFlag */ slang_ir_node *top, *cond; cond = _slang_gen_operation(A, pred); @@ -4947,6 +4933,8 @@ _slang_gen_operation(slang_assemble_ctx * A, slang_operation *oper) return _slang_gen_method_call(A, oper); case SLANG_OPER_RETURN: return _slang_gen_return(A, oper); + case SLANG_OPER_RETURN_INLINED: + return _slang_gen_return(A, oper); case SLANG_OPER_LABEL: return new_label(oper->label); case SLANG_OPER_IDENTIFIER: diff --git a/src/mesa/shader/slang/slang_compile_operation.h b/src/mesa/shader/slang/slang_compile_operation.h index 17c6c3e3498..58f1edeed85 100644 --- a/src/mesa/shader/slang/slang_compile_operation.h +++ b/src/mesa/shader/slang/slang_compile_operation.h @@ -42,6 +42,7 @@ typedef enum slang_operation_type_ SLANG_OPER_CONTINUE, /* "continue" statement */ SLANG_OPER_DISCARD, /* "discard" (kill fragment) statement */ SLANG_OPER_RETURN, /* "return" [expr] */ + SLANG_OPER_RETURN_INLINED, /* "return" [expr] from inlined function */ SLANG_OPER_LABEL, /* a jump target */ SLANG_OPER_EXPRESSION, /* [expr] */ SLANG_OPER_IF, /* "if" [0] then [1] else [2] */ diff --git a/src/mesa/shader/slang/slang_print.c b/src/mesa/shader/slang/slang_print.c index bf1475f91d9..98c7877534f 100644 --- a/src/mesa/shader/slang/slang_print.c +++ b/src/mesa/shader/slang/slang_print.c @@ -261,6 +261,7 @@ slang_print_tree(const slang_operation *op, int indent) break; case SLANG_OPER_BLOCK_NEW_SCOPE: + case SLANG_OPER_NON_INLINED_CALL: spaces(indent); printf("{{ // new scope locals=%p outer=%p: ", (void *) op->locals, @@ -348,6 +349,13 @@ slang_print_tree(const slang_operation *op, int indent) slang_print_tree(&op->children[0], indent + 3); break; + case SLANG_OPER_RETURN_INLINED: + spaces(indent); + printf("RETURN_INLINED\n"); + if (op->num_children > 0) + slang_print_tree(&op->children[0], indent + 3); + break; + case SLANG_OPER_LABEL: spaces(indent); printf("LABEL %s\n", (char *) op->a_id); @@ -478,7 +486,7 @@ slang_print_tree(const slang_operation *op, int indent) (void *) scope, (void *) op->locals, (void *) op->locals->outer_scope); - assert(scope); + /*assert(scope);*/ } } break;