ir_loop::ir_loop()
{
this->ir_type = ir_type_loop;
- this->cmp = ir_unop_neg;
- this->from = NULL;
- this->to = NULL;
- this->increment = NULL;
- this->counter = NULL;
+ this->normative_bound = -1;
}
ir_type_max /**< maximum ir_type enum number, for validation */
};
+
/**
* Base class of all IR instructions
*/
exec_list body_instructions;
/**
- * \name Loop counter and controls
- *
- * Represents a loop like a FORTRAN \c do-loop.
- *
- * \note
- * If \c from and \c to are the same value, the loop will execute once.
- */
- /*@{*/
-
- /**
- * Value which should be assigned to \c counter before the first iteration
- * of the loop. Must be non-null whenever \c counter is non-null, and vice
- * versa.
- */
- ir_rvalue *from;
-
- /**
- * Value which \c counter should be compared to in order to determine
- * whether to exit the loop. Must be non-null whenever \c counter is
- * non-null, and vice versa.
+ * Normative bound for the loop. If this value is >= 0, the back-end
+ * should generate instructions to ensure that the loop executes no more
+ * than this many times.
*/
- ir_rvalue *to;
-
- /**
- * Value which should be added to \c counter at the end of each loop
- * iteration. Must be non-null whenever \c counter is non-null, and vice
- * versa.
- */
- ir_rvalue *increment;
-
- /**
- * Variable which counts loop iterations. This is a brand new ir_variable
- * declaration (not a reference to a previously declared ir_variable, as in
- * ir_dereference_variable).
- */
- ir_variable *counter;
-
- /**
- * Comparison operation in the loop terminator.
- *
- * If any of the loop control fields are non-\c NULL, this field must be
- * one of \c ir_binop_less, \c ir_binop_greater, \c ir_binop_lequal,
- * \c ir_binop_gequal, \c ir_binop_equal, or \c ir_binop_nequal.
- *
- * Ignored if \c counter is NULL.
- */
- int cmp;
- /*@}*/
+ int normative_bound;
};
{
ir_loop *new_loop = new(mem_ctx) ir_loop();
- if (this->from)
- new_loop->from = this->from->clone(mem_ctx, ht);
- if (this->to)
- new_loop->to = this->to->clone(mem_ctx, ht);
- if (this->increment)
- new_loop->increment = this->increment->clone(mem_ctx, ht);
- if (this->counter)
- new_loop->counter = this->counter->clone(mem_ctx, ht);
+ new_loop->normative_bound = this->normative_bound;
foreach_iter(exec_list_iterator, iter, this->body_instructions) {
ir_instruction *ir = (ir_instruction *)iter.get();
new_loop->body_instructions.push_tail(ir->clone(mem_ctx, ht));
}
- new_loop->cmp = this->cmp;
return new_loop;
}
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
- if (this->counter) {
- s = this->counter->accept(v);
- if (s != visit_continue)
- return (s == visit_continue_with_parent) ? visit_continue : s;
- }
-
s = visit_list_elements(v, &this->body_instructions);
if (s == visit_stop)
return s;
- if (s != visit_continue_with_parent) {
- if (this->from) {
- s = this->from->accept(v);
- if (s != visit_continue)
- return (s == visit_continue_with_parent) ? visit_continue : s;
- }
-
- if (this->to) {
- s = this->to->accept(v);
- if (s != visit_continue)
- return (s == visit_continue_with_parent) ? visit_continue : s;
- }
-
- if (this->increment) {
- s = this->increment->accept(v);
- if (s != visit_continue)
- return (s == visit_continue_with_parent) ? visit_continue : s;
- }
- }
-
return v->visit_leave(this);
}
ir_print_visitor::visit(ir_loop *ir)
{
printf("(loop (");
- if (ir->counter != NULL)
- ir->counter->accept(this);
- printf(") (");
- if (ir->from != NULL)
- ir->from->accept(this);
- printf(") (");
- if (ir->to != NULL)
- ir->to->accept(this);
- printf(") (");
- if (ir->increment != NULL)
- ir->increment->accept(this);
+ if (ir->normative_bound >= 0)
+ printf("%d", ir->normative_bound);
printf(") (\n");
indentation++;
ir_loop *
ir_reader::read_loop(s_expression *expr)
{
- s_expression *s_counter, *s_from, *s_to, *s_inc, *s_body;
+ s_expression *s_bound_expr, *s_body, *s_bound;
- s_pattern pat[] = { "loop", s_counter, s_from, s_to, s_inc, s_body };
- if (!MATCH(expr, pat)) {
- ir_read_error(expr, "expected (loop <counter> <from> <to> "
- "<increment> <body>)");
+ s_pattern loop_pat[] = { "loop", s_bound_expr, s_body };
+ s_pattern no_bound_pat[] = { };
+ s_pattern bound_pat[] = { s_bound };
+ if (!MATCH(expr, loop_pat)) {
+ ir_read_error(expr, "expected (loop <bound> <body>)");
return NULL;
}
- // FINISHME: actually read the count/from/to fields.
-
ir_loop *loop = new(mem_ctx) ir_loop;
+
+ if (MATCH(s_bound_expr, no_bound_pat)) {
+ loop->normative_bound = -1;
+ } else if (MATCH(s_bound_expr, bound_pat)) {
+ s_int *value = SX_AS_INT(s_bound);
+ if (value == NULL) {
+ ir_read_error(s_bound_expr, "malformed loop bound");
+ delete loop;
+ return NULL;
+ }
+ loop->normative_bound = value->value();
+ } else {
+ ir_read_error(s_bound_expr, "malformed loop bound");
+ delete loop;
+ return NULL;
+ }
+
read_instructions(&loop->body_instructions, s_body, loop);
if (state->error) {
delete loop;
virtual ir_visitor_status visit_enter(ir_if *ir);
- virtual ir_visitor_status visit_enter(ir_loop *ir);
- virtual ir_visitor_status visit_leave(ir_loop *ir);
virtual ir_visitor_status visit_enter(ir_function *ir);
virtual ir_visitor_status visit_leave(ir_function *ir);
virtual ir_visitor_status visit_enter(ir_function_signature *ir);
}
-ir_visitor_status
-ir_validate::visit_enter(ir_loop *ir)
-{
- if (ir->counter != NULL && hash_table_find(ht, ir->counter) != NULL) {
- printf("ir_loop @ %p specifies already-declared variable `%s' @ %p\n",
- (void *) ir, ir->counter->name, (void *) ir->counter);
- abort();
- }
- return visit_continue;
-}
-
-
-ir_visitor_status
-ir_validate::visit_leave(ir_loop *ir)
-{
- if (ir->counter != NULL) {
- if ((ir->from == NULL) || (ir->to == NULL) || (ir->increment == NULL)) {
- printf("ir_loop has invalid loop controls:\n"
- " counter: %p\n"
- " from: %p\n"
- " to: %p\n"
- " increment: %p\n",
- (void *) ir->counter, (void *) ir->from, (void *) ir->to,
- (void *) ir->increment);
- abort();
- }
-
- if ((ir->cmp < ir_binop_less) || (ir->cmp > ir_binop_nequal)) {
- printf("ir_loop has invalid comparitor %d\n", ir->cmp);
- abort();
- }
- } else {
- if ((ir->from != NULL) || (ir->to != NULL) || (ir->increment != NULL)) {
- printf("ir_loop has invalid loop controls:\n"
- " counter: %p\n"
- " from: %p\n"
- " to: %p\n"
- " increment: %p\n",
- (void *) ir->counter, (void *) ir->from, (void *) ir->to,
- (void *) ir->increment);
- abort();
- }
- }
-
- return visit_continue;
-}
-
-
ir_visitor_status
ir_validate::visit_enter(ir_function *ir)
{
return visit_continue;
}
-
-
-ir_visitor_status
-ir_variable_refcount_visitor::visit_leave(ir_loop *ir)
-{
- /* If the loop has a counter variable, it is implicitly referenced and
- * assigned to. Note that since the LHS of an assignment is counted as a
- * reference, we actually have to increment referenced_count by 2 so that
- * later code will know that the variable isn't just assigned to.
- */
- if (ir->counter != NULL) {
- ir_variable_refcount_entry *entry =
- this->get_variable_entry(ir->counter);
- if (entry) {
- entry->referenced_count += 2;
- entry->assigned_count++;
- }
- }
-
- return visit_continue;
-}
virtual ir_visitor_status visit_enter(ir_function_signature *);
virtual ir_visitor_status visit_leave(ir_assignment *);
- virtual ir_visitor_status visit_leave(ir_loop *);
ir_variable_refcount_entry *get_variable_entry(ir_variable *var);
*
* (if (expression bool ...) (break))
*
- * and fill in the \c ir_loop::from, \c ir_loop::to, and \c ir_loop::counter
- * fields of the \c ir_loop.
+ * and fill in the \c normative_bound field of the \c ir_loop.
*
* In this process, some conditional break-statements may be eliminated
* altogether. For example, if it is provable that one loop exit condition will
* i is a loop induction variable, c is a constant, and < is any relative
* operator.
*/
- int max_iterations = ls->max_iterations;
+ unsigned max_iterations =
+ ls->max_iterations < 0 ? INT_MAX : ls->max_iterations;
- if(ir->from && ir->to && ir->increment)
- max_iterations = calculate_iterations(ir->from, ir->to, ir->increment, (ir_expression_operation)ir->cmp);
-
- if(max_iterations < 0)
- max_iterations = INT_MAX;
+ if (ir->normative_bound >= 0)
+ max_iterations = ir->normative_bound;
foreach_list(node, &ls->terminators) {
loop_terminator *t = (loop_terminator *) node;
cmp);
if (iterations >= 0) {
/* If the new iteration count is lower than the previously
- * believed iteration count, update the loop control values.
+ * believed iteration count, then add a normative bound to
+ * this loop.
*/
- if (iterations < max_iterations) {
- ir->from = init->clone(ir, NULL);
- ir->to = limit->clone(ir, NULL);
- ir->increment = lv->increment->clone(ir, NULL);
- ir->counter = lv->var->clone(ir, NULL);
- ir->cmp = cmp;
+ if ((unsigned) iterations < max_iterations) {
+ ir->normative_bound = iterations;
max_iterations = iterations;
}
ir_visitor_status
lower_bounded_loops_visitor::visit_leave(ir_loop *ir)
{
- if (ir->counter == NULL)
+ if (ir->normative_bound < 0)
return visit_continue;
exec_list new_instructions;
ir_factory f(&new_instructions, ralloc_parent(ir));
- /* Before the loop, declare the counter and initialize it to "from". */
- f.emit(ir->counter);
- f.emit(assign(ir->counter, ir->from));
+ /* Before the loop, declare the counter and initialize it to zero. */
+ ir_variable *counter = f.make_temp(glsl_type::uint_type, "counter");
+ f.emit(assign(counter, f.constant(0u)));
ir->insert_before(&new_instructions);
- /* At the top of the loop, compare the counter to "to", and break if the
- * comparison succeeds.
+ /* At the top of the loop, compare the counter to normative_bound, and
+ * break if the comparison succeeds.
*/
ir_loop_jump *brk = new(f.mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
- ir_expression_operation cmp = (ir_expression_operation) ir->cmp;
- ir->body_instructions.push_head(if_tree(expr(cmp, ir->counter, ir->to),
- brk));
+ ir_if *if_inst = if_tree(gequal(counter,
+ f.constant((unsigned) ir->normative_bound)),
+ brk);
+ ir->body_instructions.push_head(if_inst);
/* At the bottom of the loop, increment the counter. */
- ir->body_instructions.push_tail(assign(ir->counter,
- add(ir->counter, ir->increment)));
-
- /* NULL out the counter, from, to, and increment variables. */
- ir->counter = NULL;
- ir->from = NULL;
- ir->to = NULL;
- ir->increment = NULL;
+ ir->body_instructions.push_tail(assign(counter,
+ add(counter, f.constant(1u))));
+
+ /* Since we've explicitly added instructions to terminate the loop, we no
+ * longer need it to have a normative bound.
+ */
+ ir->normative_bound = -1;
this->progress = true;
return visit_continue;
((declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) break))))))
EOF
((declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) break))))))
((declare (in) float b) (declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.000000))) (break)
())))))))
((declare (in) float b) (declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.0))) (break)
())))))))
((declare (in) float b) (declare (out) float a) (declare (out) float c)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.000000)))
((assign (x) (var_ref c) (constant float (1.000000))) break)
((declare (in) float b) (declare (out) float a) (declare (out) float c)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.0)))
((assign (x) (var_ref c) (constant float (1.000000))) break)
((declare (in) float b) (declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.000000))) ()
(break))))))))
((declare (in) float b) (declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.0))) ()
(break))))))))
((declare (in) float b) (declare (out) float a) (declare (out) float c)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.000000))) ()
((assign (x) (var_ref c) (constant float (1.000000))) break))))))))
((declare (in) float b) (declare (out) float a) (declare (out) float c)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(if (expression bool > (var_ref b) (constant float (0.0))) ()
((assign (x) (var_ref c) (constant float (1.000000))) break))))))))
(declare (in) float cb)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((if (expression bool > (var_ref a) (constant float (0.000000)))
((if (expression bool > (var_ref ba) (constant float (0.000000)))
((if (expression bool > (var_ref bb) (constant float (0.000000)))
(signature void (parameters)
((declare (temporary) bool break_flag)
(assign (x) (var_ref break_flag) (constant bool (0)))
- (loop () () () ()
+ (loop ()
((declare (temporary) bool execute_flag)
(assign (x) (var_ref execute_flag) (constant bool (1)))
(if (expression bool > (var_ref a) (constant float (0.0)))
((declare (in) float aa) (declare (in) float ab) (declare (in) float b)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((if (expression bool > (var_ref aa) (constant float (0.000000)))
((if (expression bool > (var_ref ab) (constant float (0.000000)))
(continue)
(signature void (parameters)
((declare (temporary) bool break_flag)
(assign (x) (var_ref break_flag) (constant bool (0)))
- (loop () () () ()
+ (loop ()
((declare (temporary) bool execute_flag)
(assign (x) (var_ref execute_flag) (constant bool (1)))
(if (expression bool > (var_ref aa) (constant float (0.0)))
((return))
()))
())
- (loop () () () ()
+ (loop ()
((if (expression bool > (var_ref b) (constant float (0.000000)))
((if (expression bool > (var_ref c) (constant float (0.000000))) (break)
(continue)))
()))
())
(if (var_ref execute_flag)
- ((loop () () () ()
+ ((loop ()
((if (expression bool > (var_ref b) (constant float (0.0)))
((if (expression bool > (var_ref c) (constant float (0.0))) ()
(continue)))
((declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) continue))))))
EOF
((declare (out) float a)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))))))))
((declare (out) float a) (declare (out) float b)
(function sub
(signature float (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(return (constant float (2.000000)))))
(assign (x) (var_ref b) (constant float (3.000000)))
((declare (out) float a) (declare (out) float b)
(function sub
(signature float (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(return (constant float (2.000000)))))
(assign (x) (var_ref b) (constant float (3.000000)))
((declare (out) float a) (declare (out) float b)
(function sub
(signature float (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(return (constant float (2.000000)))))
(assign (x) (var_ref b) (constant float (3.000000)))
(declare (temporary) float return_value)
(declare (temporary) bool return_flag)
(assign (x) (var_ref return_flag) (constant bool (0)))
- (loop () () () ()
+ (loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(assign (x) (var_ref return_value) (constant float (2.000000)))
(assign (x) (var_ref return_flag) (constant bool (1)))
((declare (out) float a) (declare (out) float b)
(function sub
(signature float (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(return (constant float (2.000000)))))
(assign (x) (var_ref b) (constant float (3.000000)))
(declare (temporary) float return_value)
(declare (temporary) bool return_flag)
(assign (x) (var_ref return_flag) (constant bool (0)))
- (loop () () () ()
+ (loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(assign (x) (var_ref return_value) (constant float (2.000000)))
(assign (x) (var_ref return_flag) (constant bool (1)))
((declare (out) float a) (declare (out) float b)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) (return)))
(assign (x) (var_ref b) (constant float (2.000000)))))))
EOF
((declare (out) float a) (declare (out) float b)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) (return)))
(assign (x) (var_ref b) (constant float (2.000000)))))))
((declare (out) float a) (declare (out) float b)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) (return)))
(assign (x) (var_ref b) (constant float (2.000000)))))))
EOF
(signature void (parameters)
((declare (temporary) bool return_flag)
(assign (x) (var_ref return_flag) (constant bool (0)))
- (loop () () () ()
+ (loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(assign (x) (var_ref return_flag) (constant bool (1)))
break))
((declare (out) float a) (declare (out) float b)
(function main
(signature void (parameters)
- ((loop () () () ()
+ ((loop ()
((assign (x) (var_ref a) (constant float (1.000000))) (return)))
(assign (x) (var_ref b) (constant float (2.000000)))))))
EOF
(signature void (parameters)
((declare (temporary) bool return_flag)
(assign (x) (var_ref return_flag) (constant bool (0)))
- (loop () () () ()
+ (loop ()
((assign (x) (var_ref a) (constant float (1.000000)))
(assign (x) (var_ref return_flag) (constant bool (1)))
break))
void
fs_visitor::visit(ir_loop *ir)
{
- /* Any bounded loops should have been lowered by lower_bounded_loops(). */
- assert(ir->counter == NULL);
+ /* Any normative loop bounds should have been lowered by
+ * lower_bounded_loops().
+ */
+ assert(ir->normative_bound < 0);
if (brw->gen < 6 && dispatch_width == 16) {
fail("Can't support (non-uniform) control flow on 16-wide\n");
void
vec4_visitor::visit(ir_loop *ir)
{
- /* Any bounded loops should have been lowered by lower_bounded_loops(). */
- assert(ir->counter == NULL);
+ /* Any normative loop bounds should have been lowered by
+ * lower_bounded_loops().
+ */
+ assert(ir->normative_bound < 0);
/* We don't want debugging output to print the whole body of the
* loop as the annotation.
void
ir_to_mesa_visitor::visit(ir_loop *ir)
{
- /* Any bounded loops should have been lowered by lower_bounded_loops(). */
- assert(ir->counter == NULL);
+ /* Any normative loop bounds should have been lowered by
+ * lower_bounded_loops().
+ */
+ assert(ir->normative_bound < 0);
emit(NULL, OPCODE_BGNLOOP);
void
glsl_to_tgsi_visitor::visit(ir_loop *ir)
{
- /* Any bounded loops should have been lowered by lower_bounded_loops(). */
- assert(ir->counter == NULL);
+ /* Any normative loop bounds should have been lowered by
+ * lower_bounded_loops().
+ */
+ assert(ir->normative_bound < 0);
emit(NULL, TGSI_OPCODE_BGNLOOP);