#include "util/ralloc.h"
#include "glsl/nir/nir.h"
+#include "glsl/nir/nir_control_flow.h"
#include "glsl/nir/nir_builder.h"
#include "glsl/list.h"
#include "glsl/shader_enums.h"
nir/nir_array.h \
nir/nir_builder.h \
nir/nir_constant_expressions.h \
+ nir/nir_control_flow.c \
+ nir/nir_control_flow.h \
+ nir/nir_control_flow_private.h \
nir/nir_dominance.c \
nir/nir_from_ssa.c \
nir/nir_intrinsics.c \
*/
#include "glsl_to_nir.h"
+#include "nir_control_flow.h"
#include "ir_visitor.h"
#include "ir_hierarchical_visitor.h"
#include "ir.h"
*/
#include "nir.h"
+#include "nir_control_flow_private.h"
#include <assert.h>
nir_shader *
dest->saturate = src->saturate;
}
-static inline void
-block_add_pred(nir_block *block, nir_block *pred)
-{
- _mesa_set_add(block->predecessors, pred);
-}
static void
cf_init(nir_cf_node *node, nir_cf_node_type type)
node->type = type;
}
-static void
-link_blocks(nir_block *pred, nir_block *succ1, nir_block *succ2)
-{
- pred->successors[0] = succ1;
- block_add_pred(succ1, pred);
-
- pred->successors[1] = succ2;
- if (succ2 != NULL)
- block_add_pred(succ2, pred);
-}
-
-static void
-unlink_blocks(nir_block *pred, nir_block *succ)
-{
- if (pred->successors[0] == succ) {
- pred->successors[0] = pred->successors[1];
- pred->successors[1] = NULL;
- } else {
- assert(pred->successors[1] == succ);
- pred->successors[1] = NULL;
- }
-
- struct set_entry *entry = _mesa_set_search(succ->predecessors, pred);
-
- assert(entry);
-
- _mesa_set_remove(succ->predecessors, entry);
-}
-
-static void
-unlink_block_successors(nir_block *block)
-{
- if (block->successors[0] != NULL)
- unlink_blocks(block, block->successors[0]);
- if (block->successors[1] != NULL)
- unlink_blocks(block, block->successors[1]);
-}
-
-
nir_function_impl *
nir_function_impl_create(nir_function_overload *overload)
{
return load;
}
-/**
- * \name Control flow modification
- *
- * These functions modify the control flow tree while keeping the control flow
- * graph up-to-date. The invariants respected are:
- * 1. Each then statement, else statement, or loop body must have at least one
- * control flow node.
- * 2. Each if-statement and loop must have one basic block before it and one
- * after.
- * 3. Two basic blocks cannot be directly next to each other.
- * 4. If a basic block has a jump instruction, there must be only one and it
- * must be at the end of the block.
- * 5. The CFG must always be connected - this means that we must insert a fake
- * CFG edge for loops with no break statement.
- *
- * The purpose of the second one is so that we have places to insert code during
- * GCM, as well as eliminating the possibility of critical edges.
- */
-/*@{*/
-
-static void
-link_non_block_to_block(nir_cf_node *node, nir_block *block)
-{
- if (node->type == nir_cf_node_if) {
- /*
- * We're trying to link an if to a block after it; this just means linking
- * the last block of the then and else branches.
- */
-
- nir_if *if_stmt = nir_cf_node_as_if(node);
-
- nir_cf_node *last_then = nir_if_last_then_node(if_stmt);
- assert(last_then->type == nir_cf_node_block);
- nir_block *last_then_block = nir_cf_node_as_block(last_then);
-
- nir_cf_node *last_else = nir_if_last_else_node(if_stmt);
- assert(last_else->type == nir_cf_node_block);
- nir_block *last_else_block = nir_cf_node_as_block(last_else);
-
- if (exec_list_is_empty(&last_then_block->instr_list) ||
- nir_block_last_instr(last_then_block)->type != nir_instr_type_jump) {
- unlink_block_successors(last_then_block);
- link_blocks(last_then_block, block, NULL);
- }
-
- if (exec_list_is_empty(&last_else_block->instr_list) ||
- nir_block_last_instr(last_else_block)->type != nir_instr_type_jump) {
- unlink_block_successors(last_else_block);
- link_blocks(last_else_block, block, NULL);
- }
- } else {
- assert(node->type == nir_cf_node_loop);
-
- /*
- * We can only get to this codepath if we're inserting a new loop, or
- * at least a loop with no break statements; we can't insert break
- * statements into a loop when we haven't inserted it into the CFG
- * because we wouldn't know which block comes after the loop
- * and therefore, which block should be the successor of the block with
- * the break). Therefore, we need to insert a fake edge (see invariant
- * #5).
- */
-
- nir_loop *loop = nir_cf_node_as_loop(node);
-
- nir_cf_node *last = nir_loop_last_cf_node(loop);
- assert(last->type == nir_cf_node_block);
- nir_block *last_block = nir_cf_node_as_block(last);
-
- last_block->successors[1] = block;
- block_add_pred(block, last_block);
- }
-}
-
-static void
-link_block_to_non_block(nir_block *block, nir_cf_node *node)
-{
- if (node->type == nir_cf_node_if) {
- /*
- * We're trying to link a block to an if after it; this just means linking
- * the block to the first block of the then and else branches.
- */
-
- nir_if *if_stmt = nir_cf_node_as_if(node);
-
- nir_cf_node *first_then = nir_if_first_then_node(if_stmt);
- assert(first_then->type == nir_cf_node_block);
- nir_block *first_then_block = nir_cf_node_as_block(first_then);
-
- nir_cf_node *first_else = nir_if_first_else_node(if_stmt);
- assert(first_else->type == nir_cf_node_block);
- nir_block *first_else_block = nir_cf_node_as_block(first_else);
-
- unlink_block_successors(block);
- link_blocks(block, first_then_block, first_else_block);
- } else {
- /*
- * For similar reasons as the corresponding case in
- * link_non_block_to_block(), don't worry about if the loop header has
- * any predecessors that need to be unlinked.
- */
-
- assert(node->type == nir_cf_node_loop);
-
- nir_loop *loop = nir_cf_node_as_loop(node);
-
- nir_cf_node *loop_header = nir_loop_first_cf_node(loop);
- assert(loop_header->type == nir_cf_node_block);
- nir_block *loop_header_block = nir_cf_node_as_block(loop_header);
-
- unlink_block_successors(block);
- link_blocks(block, loop_header_block, NULL);
- }
-
-}
-
-/**
- * Takes a basic block and inserts a new empty basic block before it, making its
- * predecessors point to the new block. This essentially splits the block into
- * an empty header and a body so that another non-block CF node can be inserted
- * between the two. Note that this does *not* link the two basic blocks, so
- * some kind of cleanup *must* be performed after this call.
- */
-
-static nir_block *
-split_block_beginning(nir_block *block)
-{
- nir_block *new_block = nir_block_create(ralloc_parent(block));
- new_block->cf_node.parent = block->cf_node.parent;
- exec_node_insert_node_before(&block->cf_node.node, &new_block->cf_node.node);
-
- struct set_entry *entry;
- set_foreach(block->predecessors, entry) {
- nir_block *pred = (nir_block *) entry->key;
-
- unlink_blocks(pred, block);
- link_blocks(pred, new_block, NULL);
- }
-
- return new_block;
-}
-
-static void
-rewrite_phi_preds(nir_block *block, nir_block *old_pred, nir_block *new_pred)
-{
- nir_foreach_instr_safe(block, instr) {
- if (instr->type != nir_instr_type_phi)
- break;
-
- nir_phi_instr *phi = nir_instr_as_phi(instr);
- nir_foreach_phi_src(phi, src) {
- if (src->pred == old_pred) {
- src->pred = new_pred;
- break;
- }
- }
- }
-}
-
-/**
- * Moves the successors of source to the successors of dest, leaving both
- * successors of source NULL.
- */
-
-static void
-move_successors(nir_block *source, nir_block *dest)
-{
- nir_block *succ1 = source->successors[0];
- nir_block *succ2 = source->successors[1];
-
- if (succ1) {
- unlink_blocks(source, succ1);
- rewrite_phi_preds(succ1, source, dest);
- }
-
- if (succ2) {
- unlink_blocks(source, succ2);
- rewrite_phi_preds(succ2, source, dest);
- }
-
- unlink_block_successors(dest);
- link_blocks(dest, succ1, succ2);
-}
-
-static nir_block *
-split_block_end(nir_block *block)
-{
- nir_block *new_block = nir_block_create(ralloc_parent(block));
- new_block->cf_node.parent = block->cf_node.parent;
- exec_node_insert_after(&block->cf_node.node, &new_block->cf_node.node);
-
- move_successors(block, new_block);
-
- return new_block;
-}
-
-/**
- * Inserts a non-basic block between two basic blocks and links them together.
- */
-
-static void
-insert_non_block(nir_block *before, nir_cf_node *node, nir_block *after)
-{
- node->parent = before->cf_node.parent;
- exec_node_insert_after(&before->cf_node.node, &node->node);
- link_block_to_non_block(before, node);
- link_non_block_to_block(node, after);
-}
-
-/**
- * Inserts a non-basic block before a basic block.
- */
-
-static void
-insert_non_block_before_block(nir_cf_node *node, nir_block *block)
-{
- /* split off the beginning of block into new_block */
- nir_block *new_block = split_block_beginning(block);
-
- /* insert our node in between new_block and block */
- insert_non_block(new_block, node, block);
-}
-
-static void
-insert_non_block_after_block(nir_block *block, nir_cf_node *node)
-{
- /* split off the end of block into new_block */
- nir_block *new_block = split_block_end(block);
-
- /* insert our node in between block and new_block */
- insert_non_block(block, node, new_block);
-}
-
-/* walk up the control flow tree to find the innermost enclosed loop */
-static nir_loop *
-nearest_loop(nir_cf_node *node)
-{
- while (node->type != nir_cf_node_loop) {
- node = node->parent;
- }
-
- return nir_cf_node_as_loop(node);
-}
-
nir_function_impl *
nir_cf_node_get_function(nir_cf_node *node)
{
return nir_cf_node_as_function(node);
}
-/*
- * update the CFG after a jump instruction has been added to the end of a block
- */
-
-static void
-handle_jump(nir_block *block)
-{
- nir_instr *instr = nir_block_last_instr(block);
- nir_jump_instr *jump_instr = nir_instr_as_jump(instr);
-
- unlink_block_successors(block);
-
- nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
- nir_metadata_preserve(impl, nir_metadata_none);
-
- if (jump_instr->type == nir_jump_break ||
- jump_instr->type == nir_jump_continue) {
- nir_loop *loop = nearest_loop(&block->cf_node);
-
- if (jump_instr->type == nir_jump_continue) {
- nir_cf_node *first_node = nir_loop_first_cf_node(loop);
- assert(first_node->type == nir_cf_node_block);
- nir_block *first_block = nir_cf_node_as_block(first_node);
- link_blocks(block, first_block, NULL);
- } else {
- nir_cf_node *after = nir_cf_node_next(&loop->cf_node);
- assert(after->type == nir_cf_node_block);
- nir_block *after_block = nir_cf_node_as_block(after);
- link_blocks(block, after_block, NULL);
-
- /* If we inserted a fake link, remove it */
- nir_cf_node *last = nir_loop_last_cf_node(loop);
- assert(last->type == nir_cf_node_block);
- nir_block *last_block = nir_cf_node_as_block(last);
- if (last_block->successors[1] != NULL)
- unlink_blocks(last_block, after_block);
- }
- } else {
- assert(jump_instr->type == nir_jump_return);
- link_blocks(block, impl->end_block, NULL);
- }
-}
-
-static void
-handle_remove_jump(nir_block *block, nir_jump_type type)
-{
- unlink_block_successors(block);
-
- if (exec_node_is_tail_sentinel(block->cf_node.node.next)) {
- nir_cf_node *parent = block->cf_node.parent;
- if (parent->type == nir_cf_node_if) {
- nir_cf_node *next = nir_cf_node_next(parent);
- assert(next->type == nir_cf_node_block);
- nir_block *next_block = nir_cf_node_as_block(next);
-
- link_blocks(block, next_block, NULL);
- } else {
- assert(parent->type == nir_cf_node_loop);
- nir_loop *loop = nir_cf_node_as_loop(parent);
-
- nir_cf_node *head = nir_loop_first_cf_node(loop);
- assert(head->type == nir_cf_node_block);
- nir_block *head_block = nir_cf_node_as_block(head);
-
- link_blocks(block, head_block, NULL);
- }
- } else {
- nir_cf_node *next = nir_cf_node_next(&block->cf_node);
- if (next->type == nir_cf_node_if) {
- nir_if *next_if = nir_cf_node_as_if(next);
-
- nir_cf_node *first_then = nir_if_first_then_node(next_if);
- assert(first_then->type == nir_cf_node_block);
- nir_block *first_then_block = nir_cf_node_as_block(first_then);
-
- nir_cf_node *first_else = nir_if_first_else_node(next_if);
- assert(first_else->type == nir_cf_node_block);
- nir_block *first_else_block = nir_cf_node_as_block(first_else);
-
- link_blocks(block, first_then_block, first_else_block);
- } else {
- assert(next->type == nir_cf_node_loop);
- nir_loop *next_loop = nir_cf_node_as_loop(next);
-
- nir_cf_node *first = nir_loop_first_cf_node(next_loop);
- assert(first->type == nir_cf_node_block);
- nir_block *first_block = nir_cf_node_as_block(first);
-
- link_blocks(block, first_block, NULL);
- }
- }
-
- if (type == nir_jump_break) {
- nir_loop *loop = nearest_loop(&block->cf_node);
-
- nir_cf_node *next = nir_cf_node_next(&loop->cf_node);
- assert(next->type == nir_cf_node_block);
- nir_block *next_block = nir_cf_node_as_block(next);
-
- if (next_block->predecessors->entries == 0) {
- /* insert fake link */
- nir_cf_node *last = nir_loop_last_cf_node(loop);
- assert(last->type == nir_cf_node_block);
- nir_block *last_block = nir_cf_node_as_block(last);
-
- last_block->successors[1] = next_block;
- block_add_pred(next_block, last_block);
- }
- }
-
- nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
- nir_metadata_preserve(impl, nir_metadata_none);
-}
-
-/**
- * Inserts a basic block before another by merging the instructions.
- *
- * @param block the target of the insertion
- * @param before the block to be inserted - must not have been inserted before
- * @param has_jump whether \before has a jump instruction at the end
- */
-
-static void
-insert_block_before_block(nir_block *block, nir_block *before, bool has_jump)
-{
- assert(!has_jump || exec_list_is_empty(&block->instr_list));
-
- foreach_list_typed(nir_instr, instr, node, &before->instr_list) {
- instr->block = block;
- }
-
- exec_list_prepend(&block->instr_list, &before->instr_list);
-
- if (has_jump)
- handle_jump(block);
-}
-
-/**
- * Inserts a basic block after another by merging the instructions.
- *
- * @param block the target of the insertion
- * @param after the block to be inserted - must not have been inserted before
- * @param has_jump whether \after has a jump instruction at the end
- */
-
-static void
-insert_block_after_block(nir_block *block, nir_block *after, bool has_jump)
-{
- foreach_list_typed(nir_instr, instr, node, &after->instr_list) {
- instr->block = block;
- }
-
- exec_list_append(&block->instr_list, &after->instr_list);
-
- if (has_jump)
- handle_jump(block);
-}
-
-static void
-update_if_uses(nir_cf_node *node)
-{
- if (node->type != nir_cf_node_if)
- return;
-
- nir_if *if_stmt = nir_cf_node_as_if(node);
-
- if_stmt->condition.parent_if = if_stmt;
- if (if_stmt->condition.is_ssa) {
- list_addtail(&if_stmt->condition.use_link,
- &if_stmt->condition.ssa->if_uses);
- } else {
- list_addtail(&if_stmt->condition.use_link,
- &if_stmt->condition.reg.reg->if_uses);
- }
-}
-
-void
-nir_cf_node_insert_after(nir_cf_node *node, nir_cf_node *after)
-{
- update_if_uses(after);
-
- if (after->type == nir_cf_node_block) {
- /*
- * either node or the one after it must be a basic block, by invariant #2;
- * in either case, just merge the blocks together.
- */
- nir_block *after_block = nir_cf_node_as_block(after);
-
- bool has_jump = !exec_list_is_empty(&after_block->instr_list) &&
- nir_block_last_instr(after_block)->type == nir_instr_type_jump;
-
- if (node->type == nir_cf_node_block) {
- insert_block_after_block(nir_cf_node_as_block(node), after_block,
- has_jump);
- } else {
- nir_cf_node *next = nir_cf_node_next(node);
- assert(next->type == nir_cf_node_block);
- nir_block *next_block = nir_cf_node_as_block(next);
-
- insert_block_before_block(next_block, after_block, has_jump);
- }
- } else {
- if (node->type == nir_cf_node_block) {
- insert_non_block_after_block(nir_cf_node_as_block(node), after);
- } else {
- /*
- * We have to insert a non-basic block after a non-basic block. Since
- * every non-basic block has a basic block after it, this is equivalent
- * to inserting a non-basic block before a basic block.
- */
-
- nir_cf_node *next = nir_cf_node_next(node);
- assert(next->type == nir_cf_node_block);
- nir_block *next_block = nir_cf_node_as_block(next);
-
- insert_non_block_before_block(after, next_block);
- }
- }
-
- nir_function_impl *impl = nir_cf_node_get_function(node);
- nir_metadata_preserve(impl, nir_metadata_none);
-}
-
-void
-nir_cf_node_insert_before(nir_cf_node *node, nir_cf_node *before)
-{
- update_if_uses(before);
-
- if (before->type == nir_cf_node_block) {
- nir_block *before_block = nir_cf_node_as_block(before);
-
- bool has_jump = !exec_list_is_empty(&before_block->instr_list) &&
- nir_block_last_instr(before_block)->type == nir_instr_type_jump;
-
- if (node->type == nir_cf_node_block) {
- insert_block_before_block(nir_cf_node_as_block(node), before_block,
- has_jump);
- } else {
- nir_cf_node *prev = nir_cf_node_prev(node);
- assert(prev->type == nir_cf_node_block);
- nir_block *prev_block = nir_cf_node_as_block(prev);
-
- insert_block_after_block(prev_block, before_block, has_jump);
- }
- } else {
- if (node->type == nir_cf_node_block) {
- insert_non_block_before_block(before, nir_cf_node_as_block(node));
- } else {
- /*
- * We have to insert a non-basic block before a non-basic block. This
- * is equivalent to inserting a non-basic block after a basic block.
- */
-
- nir_cf_node *prev_node = nir_cf_node_prev(node);
- assert(prev_node->type == nir_cf_node_block);
- nir_block *prev_block = nir_cf_node_as_block(prev_node);
-
- insert_non_block_after_block(prev_block, before);
- }
- }
-
- nir_function_impl *impl = nir_cf_node_get_function(node);
- nir_metadata_preserve(impl, nir_metadata_none);
-}
-
-void
-nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node)
-{
- nir_cf_node *begin = exec_node_data(nir_cf_node, list->head, node);
- nir_cf_node_insert_before(begin, node);
-}
-
-void
-nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node)
-{
- nir_cf_node *end = exec_node_data(nir_cf_node, list->tail_pred, node);
- nir_cf_node_insert_after(end, node);
-}
-
-/**
- * Stitch two basic blocks together into one. The aggregate must have the same
- * predecessors as the first and the same successors as the second.
- */
-
-static void
-stitch_blocks(nir_block *before, nir_block *after)
-{
- /*
- * We move after into before, so we have to deal with up to 2 successors vs.
- * possibly a large number of predecessors.
- *
- * TODO: special case when before is empty and after isn't?
- */
-
- move_successors(after, before);
-
- foreach_list_typed(nir_instr, instr, node, &after->instr_list) {
- instr->block = before;
- }
-
- exec_list_append(&before->instr_list, &after->instr_list);
- exec_node_remove(&after->cf_node.node);
-}
-
-static void
-remove_defs_uses(nir_instr *instr);
-
-static void
-cleanup_cf_node(nir_cf_node *node)
-{
- switch (node->type) {
- case nir_cf_node_block: {
- nir_block *block = nir_cf_node_as_block(node);
- /* We need to walk the instructions and clean up defs/uses */
- nir_foreach_instr(block, instr) {
- if (instr->type != nir_instr_type_jump)
- nir_instr_remove(instr);
- }
- break;
- }
-
- case nir_cf_node_if: {
- nir_if *if_stmt = nir_cf_node_as_if(node);
- foreach_list_typed(nir_cf_node, child, node, &if_stmt->then_list)
- cleanup_cf_node(child);
- foreach_list_typed(nir_cf_node, child, node, &if_stmt->else_list)
- cleanup_cf_node(child);
-
- list_del(&if_stmt->condition.use_link);
- break;
- }
-
- case nir_cf_node_loop: {
- nir_loop *loop = nir_cf_node_as_loop(node);
- foreach_list_typed(nir_cf_node, child, node, &loop->body)
- cleanup_cf_node(child);
- break;
- }
- case nir_cf_node_function: {
- nir_function_impl *impl = nir_cf_node_as_function(node);
- foreach_list_typed(nir_cf_node, child, node, &impl->body)
- cleanup_cf_node(child);
- break;
- }
- default:
- unreachable("Invalid CF node type");
- }
-}
-
-void
-nir_cf_node_remove(nir_cf_node *node)
-{
- nir_function_impl *impl = nir_cf_node_get_function(node);
- nir_metadata_preserve(impl, nir_metadata_none);
-
- if (node->type == nir_cf_node_block) {
- /*
- * Basic blocks can't really be removed by themselves, since they act as
- * padding between the non-basic blocks. So all we do here is empty the
- * block of instructions.
- *
- * TODO: could we assert here?
- */
- exec_list_make_empty(&nir_cf_node_as_block(node)->instr_list);
- } else {
- nir_cf_node *before = nir_cf_node_prev(node);
- assert(before->type == nir_cf_node_block);
- nir_block *before_block = nir_cf_node_as_block(before);
-
- nir_cf_node *after = nir_cf_node_next(node);
- assert(after->type == nir_cf_node_block);
- nir_block *after_block = nir_cf_node_as_block(after);
-
- exec_node_remove(&node->node);
- stitch_blocks(before_block, after_block);
- }
-
- cleanup_cf_node(node);
-}
-
static bool
add_use_cb(nir_src *src, void *state)
{
exec_node_insert_after(&instr->node, &after->node);
if (after->type == nir_instr_type_jump)
- handle_jump(after->block);
+ nir_handle_add_jump(after->block);
}
void
exec_list_push_head(&block->instr_list, &before->node);
if (before->type == nir_instr_type_jump)
- handle_jump(block);
+ nir_handle_add_jump(block);
}
void
exec_list_push_tail(&block->instr_list, &after->node);
if (after->type == nir_instr_type_jump)
- handle_jump(block);
+ nir_handle_add_jump(block);
}
void
if (instr->type == nir_instr_type_jump) {
nir_jump_instr *jump_instr = nir_instr_as_jump(instr);
- handle_remove_jump(instr->block, jump_instr->type);
+ nir_handle_remove_jump(instr->block, jump_instr->type);
}
}
nir_function_impl *nir_cf_node_get_function(nir_cf_node *node);
-/** puts a control flow node immediately after another control flow node */
-void nir_cf_node_insert_after(nir_cf_node *node, nir_cf_node *after);
-
-/** puts a control flow node immediately before another control flow node */
-void nir_cf_node_insert_before(nir_cf_node *node, nir_cf_node *before);
-
-/** puts a control flow node at the beginning of a list from an if, loop, or function */
-void nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node);
-
-/** puts a control flow node at the end of a list from an if, loop, or function */
-void nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node);
-
-/** removes a control flow node, doing any cleanup necessary */
-void nir_cf_node_remove(nir_cf_node *node);
-
/** requests that the given pieces of metadata be generated */
void nir_metadata_require(nir_function_impl *impl, nir_metadata required);
/** dirties all but the preserved metadata */
--- /dev/null
+/*
+ * Copyright © 2014 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.
+ *
+ * Authors:
+ * Connor Abbott (cwabbott0@gmail.com)
+ *
+ */
+
+#include "nir_control_flow_private.h"
+
+/**
+ * \name Control flow modification
+ *
+ * These functions modify the control flow tree while keeping the control flow
+ * graph up-to-date. The invariants respected are:
+ * 1. Each then statement, else statement, or loop body must have at least one
+ * control flow node.
+ * 2. Each if-statement and loop must have one basic block before it and one
+ * after.
+ * 3. Two basic blocks cannot be directly next to each other.
+ * 4. If a basic block has a jump instruction, there must be only one and it
+ * must be at the end of the block.
+ * 5. The CFG must always be connected - this means that we must insert a fake
+ * CFG edge for loops with no break statement.
+ *
+ * The purpose of the second one is so that we have places to insert code during
+ * GCM, as well as eliminating the possibility of critical edges.
+ */
+/*@{*/
+
+static inline void
+block_add_pred(nir_block *block, nir_block *pred)
+{
+ _mesa_set_add(block->predecessors, pred);
+}
+
+static void
+link_blocks(nir_block *pred, nir_block *succ1, nir_block *succ2)
+{
+ pred->successors[0] = succ1;
+ block_add_pred(succ1, pred);
+
+ pred->successors[1] = succ2;
+ if (succ2 != NULL)
+ block_add_pred(succ2, pred);
+}
+
+static void
+unlink_blocks(nir_block *pred, nir_block *succ)
+{
+ if (pred->successors[0] == succ) {
+ pred->successors[0] = pred->successors[1];
+ pred->successors[1] = NULL;
+ } else {
+ assert(pred->successors[1] == succ);
+ pred->successors[1] = NULL;
+ }
+
+ struct set_entry *entry = _mesa_set_search(succ->predecessors, pred);
+
+ assert(entry);
+
+ _mesa_set_remove(succ->predecessors, entry);
+}
+
+static void
+unlink_block_successors(nir_block *block)
+{
+ if (block->successors[0] != NULL)
+ unlink_blocks(block, block->successors[0]);
+ if (block->successors[1] != NULL)
+ unlink_blocks(block, block->successors[1]);
+}
+
+static void
+link_non_block_to_block(nir_cf_node *node, nir_block *block)
+{
+ if (node->type == nir_cf_node_if) {
+ /*
+ * We're trying to link an if to a block after it; this just means linking
+ * the last block of the then and else branches.
+ */
+
+ nir_if *if_stmt = nir_cf_node_as_if(node);
+
+ nir_cf_node *last_then = nir_if_last_then_node(if_stmt);
+ assert(last_then->type == nir_cf_node_block);
+ nir_block *last_then_block = nir_cf_node_as_block(last_then);
+
+ nir_cf_node *last_else = nir_if_last_else_node(if_stmt);
+ assert(last_else->type == nir_cf_node_block);
+ nir_block *last_else_block = nir_cf_node_as_block(last_else);
+
+ if (exec_list_is_empty(&last_then_block->instr_list) ||
+ nir_block_last_instr(last_then_block)->type != nir_instr_type_jump) {
+ unlink_block_successors(last_then_block);
+ link_blocks(last_then_block, block, NULL);
+ }
+
+ if (exec_list_is_empty(&last_else_block->instr_list) ||
+ nir_block_last_instr(last_else_block)->type != nir_instr_type_jump) {
+ unlink_block_successors(last_else_block);
+ link_blocks(last_else_block, block, NULL);
+ }
+ } else {
+ assert(node->type == nir_cf_node_loop);
+
+ /*
+ * We can only get to this codepath if we're inserting a new loop, or
+ * at least a loop with no break statements; we can't insert break
+ * statements into a loop when we haven't inserted it into the CFG
+ * because we wouldn't know which block comes after the loop
+ * and therefore, which block should be the successor of the block with
+ * the break). Therefore, we need to insert a fake edge (see invariant
+ * #5).
+ */
+
+ nir_loop *loop = nir_cf_node_as_loop(node);
+
+ nir_cf_node *last = nir_loop_last_cf_node(loop);
+ assert(last->type == nir_cf_node_block);
+ nir_block *last_block = nir_cf_node_as_block(last);
+
+ last_block->successors[1] = block;
+ block_add_pred(block, last_block);
+ }
+}
+
+static void
+link_block_to_non_block(nir_block *block, nir_cf_node *node)
+{
+ if (node->type == nir_cf_node_if) {
+ /*
+ * We're trying to link a block to an if after it; this just means linking
+ * the block to the first block of the then and else branches.
+ */
+
+ nir_if *if_stmt = nir_cf_node_as_if(node);
+
+ nir_cf_node *first_then = nir_if_first_then_node(if_stmt);
+ assert(first_then->type == nir_cf_node_block);
+ nir_block *first_then_block = nir_cf_node_as_block(first_then);
+
+ nir_cf_node *first_else = nir_if_first_else_node(if_stmt);
+ assert(first_else->type == nir_cf_node_block);
+ nir_block *first_else_block = nir_cf_node_as_block(first_else);
+
+ unlink_block_successors(block);
+ link_blocks(block, first_then_block, first_else_block);
+ } else {
+ /*
+ * For similar reasons as the corresponding case in
+ * link_non_block_to_block(), don't worry about if the loop header has
+ * any predecessors that need to be unlinked.
+ */
+
+ assert(node->type == nir_cf_node_loop);
+
+ nir_loop *loop = nir_cf_node_as_loop(node);
+
+ nir_cf_node *loop_header = nir_loop_first_cf_node(loop);
+ assert(loop_header->type == nir_cf_node_block);
+ nir_block *loop_header_block = nir_cf_node_as_block(loop_header);
+
+ unlink_block_successors(block);
+ link_blocks(block, loop_header_block, NULL);
+ }
+
+}
+
+/**
+ * Takes a basic block and inserts a new empty basic block before it, making its
+ * predecessors point to the new block. This essentially splits the block into
+ * an empty header and a body so that another non-block CF node can be inserted
+ * between the two. Note that this does *not* link the two basic blocks, so
+ * some kind of cleanup *must* be performed after this call.
+ */
+
+static nir_block *
+split_block_beginning(nir_block *block)
+{
+ nir_block *new_block = nir_block_create(ralloc_parent(block));
+ new_block->cf_node.parent = block->cf_node.parent;
+ exec_node_insert_node_before(&block->cf_node.node, &new_block->cf_node.node);
+
+ struct set_entry *entry;
+ set_foreach(block->predecessors, entry) {
+ nir_block *pred = (nir_block *) entry->key;
+
+ unlink_blocks(pred, block);
+ link_blocks(pred, new_block, NULL);
+ }
+
+ return new_block;
+}
+
+static void
+rewrite_phi_preds(nir_block *block, nir_block *old_pred, nir_block *new_pred)
+{
+ nir_foreach_instr_safe(block, instr) {
+ if (instr->type != nir_instr_type_phi)
+ break;
+
+ nir_phi_instr *phi = nir_instr_as_phi(instr);
+ nir_foreach_phi_src(phi, src) {
+ if (src->pred == old_pred) {
+ src->pred = new_pred;
+ break;
+ }
+ }
+ }
+}
+
+/**
+ * Moves the successors of source to the successors of dest, leaving both
+ * successors of source NULL.
+ */
+
+static void
+move_successors(nir_block *source, nir_block *dest)
+{
+ nir_block *succ1 = source->successors[0];
+ nir_block *succ2 = source->successors[1];
+
+ if (succ1) {
+ unlink_blocks(source, succ1);
+ rewrite_phi_preds(succ1, source, dest);
+ }
+
+ if (succ2) {
+ unlink_blocks(source, succ2);
+ rewrite_phi_preds(succ2, source, dest);
+ }
+
+ unlink_block_successors(dest);
+ link_blocks(dest, succ1, succ2);
+}
+
+static nir_block *
+split_block_end(nir_block *block)
+{
+ nir_block *new_block = nir_block_create(ralloc_parent(block));
+ new_block->cf_node.parent = block->cf_node.parent;
+ exec_node_insert_after(&block->cf_node.node, &new_block->cf_node.node);
+
+ move_successors(block, new_block);
+
+ return new_block;
+}
+
+/**
+ * Inserts a non-basic block between two basic blocks and links them together.
+ */
+
+static void
+insert_non_block(nir_block *before, nir_cf_node *node, nir_block *after)
+{
+ node->parent = before->cf_node.parent;
+ exec_node_insert_after(&before->cf_node.node, &node->node);
+ link_block_to_non_block(before, node);
+ link_non_block_to_block(node, after);
+}
+
+/**
+ * Inserts a non-basic block before a basic block.
+ */
+
+static void
+insert_non_block_before_block(nir_cf_node *node, nir_block *block)
+{
+ /* split off the beginning of block into new_block */
+ nir_block *new_block = split_block_beginning(block);
+
+ /* insert our node in between new_block and block */
+ insert_non_block(new_block, node, block);
+}
+
+/* walk up the control flow tree to find the innermost enclosed loop */
+static nir_loop *
+nearest_loop(nir_cf_node *node)
+{
+ while (node->type != nir_cf_node_loop) {
+ node = node->parent;
+ }
+
+ return nir_cf_node_as_loop(node);
+}
+
+/*
+ * update the CFG after a jump instruction has been added to the end of a block
+ */
+
+void
+nir_handle_add_jump(nir_block *block)
+{
+ nir_instr *instr = nir_block_last_instr(block);
+ nir_jump_instr *jump_instr = nir_instr_as_jump(instr);
+
+ unlink_block_successors(block);
+
+ nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
+ nir_metadata_preserve(impl, nir_metadata_none);
+
+ if (jump_instr->type == nir_jump_break ||
+ jump_instr->type == nir_jump_continue) {
+ nir_loop *loop = nearest_loop(&block->cf_node);
+
+ if (jump_instr->type == nir_jump_continue) {
+ nir_cf_node *first_node = nir_loop_first_cf_node(loop);
+ assert(first_node->type == nir_cf_node_block);
+ nir_block *first_block = nir_cf_node_as_block(first_node);
+ link_blocks(block, first_block, NULL);
+ } else {
+ nir_cf_node *after = nir_cf_node_next(&loop->cf_node);
+ assert(after->type == nir_cf_node_block);
+ nir_block *after_block = nir_cf_node_as_block(after);
+ link_blocks(block, after_block, NULL);
+
+ /* If we inserted a fake link, remove it */
+ nir_cf_node *last = nir_loop_last_cf_node(loop);
+ assert(last->type == nir_cf_node_block);
+ nir_block *last_block = nir_cf_node_as_block(last);
+ if (last_block->successors[1] != NULL)
+ unlink_blocks(last_block, after_block);
+ }
+ } else {
+ assert(jump_instr->type == nir_jump_return);
+ link_blocks(block, impl->end_block, NULL);
+ }
+}
+
+void
+nir_handle_remove_jump(nir_block *block, nir_jump_type type)
+{
+ unlink_block_successors(block);
+
+ if (exec_node_is_tail_sentinel(block->cf_node.node.next)) {
+ nir_cf_node *parent = block->cf_node.parent;
+ if (parent->type == nir_cf_node_if) {
+ nir_cf_node *next = nir_cf_node_next(parent);
+ assert(next->type == nir_cf_node_block);
+ nir_block *next_block = nir_cf_node_as_block(next);
+
+ link_blocks(block, next_block, NULL);
+ } else {
+ assert(parent->type == nir_cf_node_loop);
+ nir_loop *loop = nir_cf_node_as_loop(parent);
+
+ nir_cf_node *head = nir_loop_first_cf_node(loop);
+ assert(head->type == nir_cf_node_block);
+ nir_block *head_block = nir_cf_node_as_block(head);
+
+ link_blocks(block, head_block, NULL);
+ }
+ } else {
+ nir_cf_node *next = nir_cf_node_next(&block->cf_node);
+ if (next->type == nir_cf_node_if) {
+ nir_if *next_if = nir_cf_node_as_if(next);
+
+ nir_cf_node *first_then = nir_if_first_then_node(next_if);
+ assert(first_then->type == nir_cf_node_block);
+ nir_block *first_then_block = nir_cf_node_as_block(first_then);
+
+ nir_cf_node *first_else = nir_if_first_else_node(next_if);
+ assert(first_else->type == nir_cf_node_block);
+ nir_block *first_else_block = nir_cf_node_as_block(first_else);
+
+ link_blocks(block, first_then_block, first_else_block);
+ } else {
+ assert(next->type == nir_cf_node_loop);
+ nir_loop *next_loop = nir_cf_node_as_loop(next);
+
+ nir_cf_node *first = nir_loop_first_cf_node(next_loop);
+ assert(first->type == nir_cf_node_block);
+ nir_block *first_block = nir_cf_node_as_block(first);
+
+ link_blocks(block, first_block, NULL);
+ }
+ }
+
+ if (type == nir_jump_break) {
+ nir_loop *loop = nearest_loop(&block->cf_node);
+
+ nir_cf_node *next = nir_cf_node_next(&loop->cf_node);
+ assert(next->type == nir_cf_node_block);
+ nir_block *next_block = nir_cf_node_as_block(next);
+
+ if (next_block->predecessors->entries == 0) {
+ /* insert fake link */
+ nir_cf_node *last = nir_loop_last_cf_node(loop);
+ assert(last->type == nir_cf_node_block);
+ nir_block *last_block = nir_cf_node_as_block(last);
+
+ last_block->successors[1] = next_block;
+ block_add_pred(next_block, last_block);
+ }
+ }
+
+ nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
+ nir_metadata_preserve(impl, nir_metadata_none);
+}
+
+static void
+insert_non_block_after_block(nir_block *block, nir_cf_node *node)
+{
+ /* split off the end of block into new_block */
+ nir_block *new_block = split_block_end(block);
+
+ /* insert our node in between block and new_block */
+ insert_non_block(block, node, new_block);
+}
+
+/**
+ * Inserts a basic block before another by merging the instructions.
+ *
+ * @param block the target of the insertion
+ * @param before the block to be inserted - must not have been inserted before
+ * @param has_jump whether \before has a jump instruction at the end
+ */
+
+static void
+insert_block_before_block(nir_block *block, nir_block *before, bool has_jump)
+{
+ assert(!has_jump || exec_list_is_empty(&block->instr_list));
+
+ foreach_list_typed(nir_instr, instr, node, &before->instr_list) {
+ instr->block = block;
+ }
+
+ exec_list_prepend(&block->instr_list, &before->instr_list);
+
+ if (has_jump)
+ nir_handle_add_jump(block);
+}
+
+/**
+ * Inserts a basic block after another by merging the instructions.
+ *
+ * @param block the target of the insertion
+ * @param after the block to be inserted - must not have been inserted before
+ * @param has_jump whether \after has a jump instruction at the end
+ */
+
+static void
+insert_block_after_block(nir_block *block, nir_block *after, bool has_jump)
+{
+ foreach_list_typed(nir_instr, instr, node, &after->instr_list) {
+ instr->block = block;
+ }
+
+ exec_list_append(&block->instr_list, &after->instr_list);
+
+ if (has_jump)
+ nir_handle_add_jump(block);
+}
+
+static void
+update_if_uses(nir_cf_node *node)
+{
+ if (node->type != nir_cf_node_if)
+ return;
+
+ nir_if *if_stmt = nir_cf_node_as_if(node);
+
+ if_stmt->condition.parent_if = if_stmt;
+ if (if_stmt->condition.is_ssa) {
+ list_addtail(&if_stmt->condition.use_link,
+ &if_stmt->condition.ssa->if_uses);
+ } else {
+ list_addtail(&if_stmt->condition.use_link,
+ &if_stmt->condition.reg.reg->if_uses);
+ }
+}
+
+void
+nir_cf_node_insert_after(nir_cf_node *node, nir_cf_node *after)
+{
+ update_if_uses(after);
+
+ if (after->type == nir_cf_node_block) {
+ /*
+ * either node or the one after it must be a basic block, by invariant #2;
+ * in either case, just merge the blocks together.
+ */
+ nir_block *after_block = nir_cf_node_as_block(after);
+
+ bool has_jump = !exec_list_is_empty(&after_block->instr_list) &&
+ nir_block_last_instr(after_block)->type == nir_instr_type_jump;
+
+ if (node->type == nir_cf_node_block) {
+ insert_block_after_block(nir_cf_node_as_block(node), after_block,
+ has_jump);
+ } else {
+ nir_cf_node *next = nir_cf_node_next(node);
+ assert(next->type == nir_cf_node_block);
+ nir_block *next_block = nir_cf_node_as_block(next);
+
+ insert_block_before_block(next_block, after_block, has_jump);
+ }
+ } else {
+ if (node->type == nir_cf_node_block) {
+ insert_non_block_after_block(nir_cf_node_as_block(node), after);
+ } else {
+ /*
+ * We have to insert a non-basic block after a non-basic block. Since
+ * every non-basic block has a basic block after it, this is equivalent
+ * to inserting a non-basic block before a basic block.
+ */
+
+ nir_cf_node *next = nir_cf_node_next(node);
+ assert(next->type == nir_cf_node_block);
+ nir_block *next_block = nir_cf_node_as_block(next);
+
+ insert_non_block_before_block(after, next_block);
+ }
+ }
+
+ nir_function_impl *impl = nir_cf_node_get_function(node);
+ nir_metadata_preserve(impl, nir_metadata_none);
+}
+
+void
+nir_cf_node_insert_before(nir_cf_node *node, nir_cf_node *before)
+{
+ update_if_uses(before);
+
+ if (before->type == nir_cf_node_block) {
+ nir_block *before_block = nir_cf_node_as_block(before);
+
+ bool has_jump = !exec_list_is_empty(&before_block->instr_list) &&
+ nir_block_last_instr(before_block)->type == nir_instr_type_jump;
+
+ if (node->type == nir_cf_node_block) {
+ insert_block_before_block(nir_cf_node_as_block(node), before_block,
+ has_jump);
+ } else {
+ nir_cf_node *prev = nir_cf_node_prev(node);
+ assert(prev->type == nir_cf_node_block);
+ nir_block *prev_block = nir_cf_node_as_block(prev);
+
+ insert_block_after_block(prev_block, before_block, has_jump);
+ }
+ } else {
+ if (node->type == nir_cf_node_block) {
+ insert_non_block_before_block(before, nir_cf_node_as_block(node));
+ } else {
+ /*
+ * We have to insert a non-basic block before a non-basic block. This
+ * is equivalent to inserting a non-basic block after a basic block.
+ */
+
+ nir_cf_node *prev_node = nir_cf_node_prev(node);
+ assert(prev_node->type == nir_cf_node_block);
+ nir_block *prev_block = nir_cf_node_as_block(prev_node);
+
+ insert_non_block_after_block(prev_block, before);
+ }
+ }
+
+ nir_function_impl *impl = nir_cf_node_get_function(node);
+ nir_metadata_preserve(impl, nir_metadata_none);
+}
+
+void
+nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node)
+{
+ nir_cf_node *begin = exec_node_data(nir_cf_node, list->head, node);
+ nir_cf_node_insert_before(begin, node);
+}
+
+void
+nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node)
+{
+ nir_cf_node *end = exec_node_data(nir_cf_node, list->tail_pred, node);
+ nir_cf_node_insert_after(end, node);
+}
+
+/**
+ * Stitch two basic blocks together into one. The aggregate must have the same
+ * predecessors as the first and the same successors as the second.
+ */
+
+static void
+stitch_blocks(nir_block *before, nir_block *after)
+{
+ /*
+ * We move after into before, so we have to deal with up to 2 successors vs.
+ * possibly a large number of predecessors.
+ *
+ * TODO: special case when before is empty and after isn't?
+ */
+
+ move_successors(after, before);
+
+ foreach_list_typed(nir_instr, instr, node, &after->instr_list) {
+ instr->block = before;
+ }
+
+ exec_list_append(&before->instr_list, &after->instr_list);
+ exec_node_remove(&after->cf_node.node);
+}
+
+
+static void
+cleanup_cf_node(nir_cf_node *node)
+{
+ switch (node->type) {
+ case nir_cf_node_block: {
+ nir_block *block = nir_cf_node_as_block(node);
+ /* We need to walk the instructions and clean up defs/uses */
+ nir_foreach_instr_safe(block, instr)
+ if (instr->type != nir_instr_type_jump)
+ nir_instr_remove(instr);
+ break;
+ }
+
+ case nir_cf_node_if: {
+ nir_if *if_stmt = nir_cf_node_as_if(node);
+ foreach_list_typed(nir_cf_node, child, node, &if_stmt->then_list)
+ cleanup_cf_node(child);
+ foreach_list_typed(nir_cf_node, child, node, &if_stmt->else_list)
+ cleanup_cf_node(child);
+
+ list_del(&if_stmt->condition.use_link);
+ break;
+ }
+
+ case nir_cf_node_loop: {
+ nir_loop *loop = nir_cf_node_as_loop(node);
+ foreach_list_typed(nir_cf_node, child, node, &loop->body)
+ cleanup_cf_node(child);
+ break;
+ }
+ case nir_cf_node_function: {
+ nir_function_impl *impl = nir_cf_node_as_function(node);
+ foreach_list_typed(nir_cf_node, child, node, &impl->body)
+ cleanup_cf_node(child);
+ break;
+ }
+ default:
+ unreachable("Invalid CF node type");
+ }
+}
+
+void
+nir_cf_node_remove(nir_cf_node *node)
+{
+ nir_function_impl *impl = nir_cf_node_get_function(node);
+ nir_metadata_preserve(impl, nir_metadata_none);
+
+ if (node->type == nir_cf_node_block) {
+ /*
+ * Basic blocks can't really be removed by themselves, since they act as
+ * padding between the non-basic blocks. So all we do here is empty the
+ * block of instructions.
+ *
+ * TODO: could we assert here?
+ */
+ exec_list_make_empty(&nir_cf_node_as_block(node)->instr_list);
+ } else {
+ nir_cf_node *before = nir_cf_node_prev(node);
+ assert(before->type == nir_cf_node_block);
+ nir_block *before_block = nir_cf_node_as_block(before);
+
+ nir_cf_node *after = nir_cf_node_next(node);
+ assert(after->type == nir_cf_node_block);
+ nir_block *after_block = nir_cf_node_as_block(after);
+
+ exec_node_remove(&node->node);
+ stitch_blocks(before_block, after_block);
+ }
+
+ cleanup_cf_node(node);
+}
--- /dev/null
+/*
+ * Copyright © 2014 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.
+ *
+ * Authors:
+ * Connor Abbott (cwabbott0@gmail.com)
+ *
+ */
+
+#include "nir.h"
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** NIR Control Flow Modification
+ *
+ * This file contains various API's that make modifying control flow in NIR,
+ * while maintaining the invariants checked by the validator, much easier.
+ */
+
+/** puts a control flow node immediately after another control flow node */
+void nir_cf_node_insert_after(nir_cf_node *node, nir_cf_node *after);
+
+/** puts a control flow node immediately before another control flow node */
+void nir_cf_node_insert_before(nir_cf_node *node, nir_cf_node *before);
+
+/** puts a control flow node at the beginning of a list from an if, loop, or function */
+void nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node);
+
+/** puts a control flow node at the end of a list from an if, loop, or function */
+void nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node);
+
+/** removes a control flow node, doing any cleanup necessary */
+void nir_cf_node_remove(nir_cf_node *node);
+
+#ifdef __cplusplus
+}
+#endif
--- /dev/null
+/*
+ * Copyright © 2014 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.
+ *
+ * Authors:
+ * Connor Abbott (cwabbott0@gmail.com)
+ *
+ */
+
+#include "nir_control_flow.h"
+
+#pragma once
+
+/* Internal control-flow modification functions used when inserting/removing
+ * instructions.
+ */
+
+void nir_handle_add_jump(nir_block *block);
+void nir_handle_remove_jump(nir_block *block, nir_jump_type type);
*/
#include "nir.h"
+#include "nir_control_flow.h"
/*
* Implements a small peephole optimization that looks for
projects / mesa.git / commitdiff