834 lines
25 KiB
C
834 lines
25 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* 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 inline void
|
|
block_remove_pred(nir_block *block, nir_block *pred)
|
|
{
|
|
struct set_entry *entry = _mesa_set_search(block->predecessors, pred);
|
|
|
|
assert(entry);
|
|
|
|
_mesa_set_remove(block->predecessors, entry);
|
|
}
|
|
|
|
static void
|
|
link_blocks(nir_block *pred, nir_block *succ1, nir_block *succ2)
|
|
{
|
|
pred->successors[0] = succ1;
|
|
if (succ1 != NULL)
|
|
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;
|
|
}
|
|
|
|
block_remove_pred(succ, pred);
|
|
}
|
|
|
|
static void
|
|
unlink_block_successors(nir_block *block)
|
|
{
|
|
if (block->successors[1] != NULL)
|
|
unlink_blocks(block, block->successors[1]);
|
|
if (block->successors[0] != NULL)
|
|
unlink_blocks(block, block->successors[0]);
|
|
}
|
|
|
|
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_block *last_then_block = nir_if_last_then_block(if_stmt);
|
|
nir_block *last_else_block = nir_if_last_else_block(if_stmt);
|
|
|
|
if (!nir_block_ends_in_jump(last_then_block)) {
|
|
unlink_block_successors(last_then_block);
|
|
link_blocks(last_then_block, block, NULL);
|
|
}
|
|
|
|
if (!nir_block_ends_in_jump(last_else_block)) {
|
|
unlink_block_successors(last_else_block);
|
|
link_blocks(last_else_block, block, NULL);
|
|
}
|
|
} else {
|
|
assert(node->type == nir_cf_node_loop);
|
|
}
|
|
}
|
|
|
|
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_block *first_then_block = nir_if_first_then_block(if_stmt);
|
|
nir_block *first_else_block = nir_if_first_else_block(if_stmt);
|
|
|
|
unlink_block_successors(block);
|
|
link_blocks(block, first_then_block, first_else_block);
|
|
} else if (node->type == nir_cf_node_loop) {
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
nir_loop *loop = nir_cf_node_as_loop(node);
|
|
|
|
nir_block *loop_header_block = nir_loop_first_block(loop);
|
|
|
|
unlink_block_successors(block);
|
|
link_blocks(block, loop_header_block, NULL);
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* Replace a block's successor with a different one.
|
|
*/
|
|
static void
|
|
replace_successor(nir_block *block, nir_block *old_succ, nir_block *new_succ)
|
|
{
|
|
if (block->successors[0] == old_succ) {
|
|
block->successors[0] = new_succ;
|
|
} else {
|
|
assert(block->successors[1] == old_succ);
|
|
block->successors[1] = new_succ;
|
|
}
|
|
|
|
block_remove_pred(old_succ, block);
|
|
block_add_pred(new_succ, block);
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
|
|
set_foreach(block->predecessors, entry) {
|
|
nir_block *pred = (nir_block *) entry->key;
|
|
replace_successor(pred, block, new_block);
|
|
}
|
|
|
|
/* Any phi nodes must stay part of the new block, or else their
|
|
* sources will be messed up.
|
|
*/
|
|
nir_foreach_instr_safe(instr, block) {
|
|
if (instr->type != nir_instr_type_phi)
|
|
break;
|
|
|
|
exec_node_remove(&instr->node);
|
|
instr->block = new_block;
|
|
exec_list_push_tail(&new_block->instr_list, &instr->node);
|
|
}
|
|
|
|
return new_block;
|
|
}
|
|
|
|
static void
|
|
rewrite_phi_preds(nir_block *block, nir_block *old_pred, nir_block *new_pred)
|
|
{
|
|
nir_foreach_instr_safe(instr, block) {
|
|
if (instr->type != nir_instr_type_phi)
|
|
break;
|
|
|
|
nir_phi_instr *phi = nir_instr_as_phi(instr);
|
|
nir_foreach_phi_src(src, phi) {
|
|
if (src->pred == old_pred) {
|
|
src->pred = new_pred;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
nir_insert_phi_undef(nir_block *block, nir_block *pred)
|
|
{
|
|
nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
|
|
nir_foreach_instr(instr, block) {
|
|
if (instr->type != nir_instr_type_phi)
|
|
break;
|
|
|
|
nir_phi_instr *phi = nir_instr_as_phi(instr);
|
|
nir_ssa_undef_instr *undef =
|
|
nir_ssa_undef_instr_create(impl->function->shader,
|
|
phi->dest.ssa.num_components,
|
|
phi->dest.ssa.bit_size);
|
|
nir_instr_insert_before_cf_list(&impl->body, &undef->instr);
|
|
nir_phi_src *src = nir_phi_instr_add_src(phi, pred, nir_src_for_ssa(&undef->def));
|
|
list_addtail(&src->src.use_link, &undef->def.uses);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
/* Given a basic block with no successors that has been inserted into the
|
|
* control flow tree, gives it the successors it would normally have assuming
|
|
* it doesn't end in a jump instruction. Also inserts phi sources with undefs
|
|
* if necessary.
|
|
*/
|
|
static void
|
|
block_add_normal_succs(nir_block *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);
|
|
nir_block *next_block = nir_cf_node_as_block(next);
|
|
|
|
link_blocks(block, next_block, NULL);
|
|
} else if (parent->type == nir_cf_node_loop) {
|
|
nir_loop *loop = nir_cf_node_as_loop(parent);
|
|
|
|
nir_block *head_block = nir_loop_first_block(loop);
|
|
|
|
link_blocks(block, head_block, NULL);
|
|
nir_insert_phi_undef(head_block, block);
|
|
} else {
|
|
nir_function_impl *impl = nir_cf_node_as_function(parent);
|
|
link_blocks(block, impl->end_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_block *first_then_block = nir_if_first_then_block(next_if);
|
|
nir_block *first_else_block = nir_if_first_else_block(next_if);
|
|
|
|
link_blocks(block, first_then_block, first_else_block);
|
|
} else if (next->type == nir_cf_node_loop) {
|
|
nir_loop *next_loop = nir_cf_node_as_loop(next);
|
|
|
|
nir_block *first_block = nir_loop_first_block(next_loop);
|
|
|
|
link_blocks(block, first_block, NULL);
|
|
nir_insert_phi_undef(first_block, block);
|
|
}
|
|
}
|
|
}
|
|
|
|
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);
|
|
|
|
if (nir_block_ends_in_jump(block)) {
|
|
/* Figure out what successor block would've had if it didn't have a jump
|
|
* instruction, and make new_block have that successor.
|
|
*/
|
|
block_add_normal_succs(new_block);
|
|
} else {
|
|
move_successors(block, new_block);
|
|
}
|
|
|
|
return new_block;
|
|
}
|
|
|
|
static nir_block *
|
|
split_block_before_instr(nir_instr *instr)
|
|
{
|
|
assert(instr->type != nir_instr_type_phi);
|
|
nir_block *new_block = split_block_beginning(instr->block);
|
|
|
|
nir_foreach_instr_safe(cur_instr, instr->block) {
|
|
if (cur_instr == instr)
|
|
break;
|
|
|
|
exec_node_remove(&cur_instr->node);
|
|
cur_instr->block = new_block;
|
|
exec_list_push_tail(&new_block->instr_list, &cur_instr->node);
|
|
}
|
|
|
|
return new_block;
|
|
}
|
|
|
|
/* Splits a basic block at the point specified by the cursor. The "before" and
|
|
* "after" arguments are filled out with the blocks resulting from the split
|
|
* if non-NULL. Note that the "beginning" of the block is actually interpreted
|
|
* as before the first non-phi instruction, and it's illegal to split a block
|
|
* before a phi instruction.
|
|
*/
|
|
|
|
static void
|
|
split_block_cursor(nir_cursor cursor,
|
|
nir_block **_before, nir_block **_after)
|
|
{
|
|
nir_block *before, *after;
|
|
switch (cursor.option) {
|
|
case nir_cursor_before_block:
|
|
after = cursor.block;
|
|
before = split_block_beginning(cursor.block);
|
|
break;
|
|
|
|
case nir_cursor_after_block:
|
|
before = cursor.block;
|
|
after = split_block_end(cursor.block);
|
|
break;
|
|
|
|
case nir_cursor_before_instr:
|
|
after = cursor.instr->block;
|
|
before = split_block_before_instr(cursor.instr);
|
|
break;
|
|
|
|
case nir_cursor_after_instr:
|
|
/* We lower this to split_block_before_instr() so that we can keep the
|
|
* after-a-jump-instr case contained to split_block_end().
|
|
*/
|
|
if (nir_instr_is_last(cursor.instr)) {
|
|
before = cursor.instr->block;
|
|
after = split_block_end(cursor.instr->block);
|
|
} else {
|
|
after = cursor.instr->block;
|
|
before = split_block_before_instr(nir_instr_next(cursor.instr));
|
|
}
|
|
break;
|
|
|
|
default:
|
|
unreachable("not reached");
|
|
}
|
|
|
|
if (_before)
|
|
*_before = before;
|
|
if (_after)
|
|
*_after = after;
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
if (!nir_block_ends_in_jump(before))
|
|
link_block_to_non_block(before, node);
|
|
link_non_block_to_block(node, after);
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
static void
|
|
remove_phi_src(nir_block *block, nir_block *pred)
|
|
{
|
|
nir_foreach_instr(instr, block) {
|
|
if (instr->type != nir_instr_type_phi)
|
|
break;
|
|
|
|
nir_phi_instr *phi = nir_instr_as_phi(instr);
|
|
nir_foreach_phi_src_safe(src, phi) {
|
|
if (src->pred == pred) {
|
|
list_del(&src->src.use_link);
|
|
exec_node_remove(&src->node);
|
|
free(src);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
if (block->successors[0])
|
|
remove_phi_src(block->successors[0], block);
|
|
if (block->successors[1])
|
|
remove_phi_src(block->successors[1], block);
|
|
unlink_block_successors(block);
|
|
|
|
nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
|
|
nir_metadata_preserve(impl, nir_metadata_none);
|
|
|
|
switch (jump_instr->type) {
|
|
case nir_jump_return:
|
|
case nir_jump_halt:
|
|
link_blocks(block, impl->end_block, NULL);
|
|
break;
|
|
|
|
case nir_jump_break: {
|
|
nir_loop *loop = nearest_loop(&block->cf_node);
|
|
nir_cf_node *after = nir_cf_node_next(&loop->cf_node);
|
|
nir_block *after_block = nir_cf_node_as_block(after);
|
|
link_blocks(block, after_block, NULL);
|
|
break;
|
|
}
|
|
|
|
case nir_jump_continue: {
|
|
nir_loop *loop = nearest_loop(&block->cf_node);
|
|
nir_block *first_block = nir_loop_first_block(loop);
|
|
link_blocks(block, first_block, NULL);
|
|
break;
|
|
}
|
|
|
|
case nir_jump_goto:
|
|
link_blocks(block, jump_instr->target, NULL);
|
|
break;
|
|
|
|
case nir_jump_goto_if:
|
|
link_blocks(block, jump_instr->else_target, jump_instr->target);
|
|
break;
|
|
|
|
default:
|
|
unreachable("Invalid jump type");
|
|
}
|
|
}
|
|
|
|
/* Removes the successor of a block with a jump. Note that the jump to be
|
|
* eliminated may be free-floating.
|
|
*/
|
|
|
|
static void
|
|
unlink_jump(nir_block *block, nir_jump_type type, bool add_normal_successors)
|
|
{
|
|
if (block->successors[0])
|
|
remove_phi_src(block->successors[0], block);
|
|
if (block->successors[1])
|
|
remove_phi_src(block->successors[1], block);
|
|
|
|
unlink_block_successors(block);
|
|
if (add_normal_successors)
|
|
block_add_normal_succs(block);
|
|
}
|
|
|
|
void
|
|
nir_handle_remove_jump(nir_block *block, nir_jump_type type)
|
|
{
|
|
unlink_jump(block, type, true);
|
|
|
|
nir_function_impl *impl = nir_cf_node_get_function(&block->cf_node);
|
|
nir_metadata_preserve(impl, nir_metadata_none);
|
|
}
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Stitch two basic blocks together into one. The aggregate must have the same
|
|
* predecessors as the first and the same successors as the second.
|
|
*
|
|
* Returns a cursor pointing at the end of the before block (i.e.m between the
|
|
* two blocks) once stiched together.
|
|
*/
|
|
|
|
static nir_cursor
|
|
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?
|
|
*/
|
|
|
|
if (nir_block_ends_in_jump(before)) {
|
|
assert(exec_list_is_empty(&after->instr_list));
|
|
if (after->successors[0])
|
|
remove_phi_src(after->successors[0], after);
|
|
if (after->successors[1])
|
|
remove_phi_src(after->successors[1], after);
|
|
unlink_block_successors(after);
|
|
exec_node_remove(&after->cf_node.node);
|
|
|
|
return nir_after_block(before);
|
|
} else {
|
|
nir_instr *last_before_instr = nir_block_last_instr(before);
|
|
|
|
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);
|
|
|
|
return last_before_instr ? nir_after_instr(last_before_instr) :
|
|
nir_before_block(before);
|
|
}
|
|
}
|
|
|
|
void
|
|
nir_cf_node_insert(nir_cursor cursor, nir_cf_node *node)
|
|
{
|
|
nir_block *before, *after;
|
|
|
|
split_block_cursor(cursor, &before, &after);
|
|
|
|
if (node->type == nir_cf_node_block) {
|
|
nir_block *block = nir_cf_node_as_block(node);
|
|
exec_node_insert_after(&before->cf_node.node, &block->cf_node.node);
|
|
block->cf_node.parent = before->cf_node.parent;
|
|
/* stitch_blocks() assumes that any block that ends with a jump has
|
|
* already been setup with the correct successors, so we need to set
|
|
* up jumps here as the block is being inserted.
|
|
*/
|
|
if (nir_block_ends_in_jump(block))
|
|
nir_handle_add_jump(block);
|
|
|
|
stitch_blocks(block, after);
|
|
stitch_blocks(before, block);
|
|
} else {
|
|
update_if_uses(node);
|
|
insert_non_block(before, node, after);
|
|
}
|
|
}
|
|
|
|
static bool
|
|
replace_ssa_def_uses(nir_ssa_def *def, void *void_impl)
|
|
{
|
|
nir_function_impl *impl = void_impl;
|
|
|
|
nir_ssa_undef_instr *undef =
|
|
nir_ssa_undef_instr_create(impl->function->shader,
|
|
def->num_components,
|
|
def->bit_size);
|
|
nir_instr_insert_before_cf_list(&impl->body, &undef->instr);
|
|
nir_ssa_def_rewrite_uses(def, &undef->def);
|
|
return true;
|
|
}
|
|
|
|
static void
|
|
cleanup_cf_node(nir_cf_node *node, nir_function_impl *impl)
|
|
{
|
|
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(instr, block) {
|
|
if (instr->type == nir_instr_type_jump) {
|
|
nir_jump_instr *jump = nir_instr_as_jump(instr);
|
|
unlink_jump(block, jump->type, false);
|
|
if (jump->type == nir_jump_goto_if)
|
|
nir_instr_rewrite_src(instr, &jump->condition, NIR_SRC_INIT);
|
|
} else {
|
|
nir_foreach_ssa_def(instr, replace_ssa_def_uses, impl);
|
|
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, impl);
|
|
foreach_list_typed(nir_cf_node, child, node, &if_stmt->else_list)
|
|
cleanup_cf_node(child, impl);
|
|
|
|
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, impl);
|
|
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, impl);
|
|
break;
|
|
}
|
|
default:
|
|
unreachable("Invalid CF node type");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Extracts everything between two cursors. Returns the cursor which is
|
|
* equivalent to the old begin/end curosors.
|
|
*/
|
|
nir_cursor
|
|
nir_cf_extract(nir_cf_list *extracted, nir_cursor begin, nir_cursor end)
|
|
{
|
|
nir_block *block_begin, *block_end, *block_before, *block_after;
|
|
|
|
if (nir_cursors_equal(begin, end)) {
|
|
exec_list_make_empty(&extracted->list);
|
|
extracted->impl = NULL; /* we shouldn't need this */
|
|
return begin;
|
|
}
|
|
|
|
split_block_cursor(begin, &block_before, &block_begin);
|
|
|
|
/* Splitting a block twice with two cursors created before either split is
|
|
* tricky and there are a couple of places it can go wrong if both cursors
|
|
* point to the same block. One is if the second cursor is an block-based
|
|
* cursor and, thanks to the split above, it ends up pointing to the wrong
|
|
* block. If it's a before_block cursor and it's in the same block as
|
|
* begin, then begin must also be a before_block cursor and it should be
|
|
* caught by the nir_cursors_equal check above and we won't get here. If
|
|
* it's an after_block cursor, we need to re-adjust to ensure that it
|
|
* points to the second one of the split blocks, regardless of which it is.
|
|
*/
|
|
if (end.option == nir_cursor_after_block && end.block == block_before)
|
|
end.block = block_begin;
|
|
|
|
split_block_cursor(end, &block_end, &block_after);
|
|
|
|
/* The second place this can all go wrong is that it could be that the
|
|
* second split places the original block after the new block in which case
|
|
* the block_begin pointer that we saved off above is pointing to the block
|
|
* at the end rather than the block in the middle like it's supposed to be.
|
|
* In this case, we have to re-adjust begin_block to point to the middle
|
|
* one.
|
|
*/
|
|
if (block_begin == block_after)
|
|
block_begin = block_end;
|
|
|
|
extracted->impl = nir_cf_node_get_function(&block_begin->cf_node);
|
|
exec_list_make_empty(&extracted->list);
|
|
|
|
/* Dominance and other block-related information is toast. */
|
|
nir_metadata_preserve(extracted->impl, nir_metadata_none);
|
|
|
|
nir_cf_node *cf_node = &block_begin->cf_node;
|
|
nir_cf_node *cf_node_end = &block_end->cf_node;
|
|
while (true) {
|
|
nir_cf_node *next = nir_cf_node_next(cf_node);
|
|
|
|
exec_node_remove(&cf_node->node);
|
|
cf_node->parent = NULL;
|
|
exec_list_push_tail(&extracted->list, &cf_node->node);
|
|
|
|
if (cf_node == cf_node_end)
|
|
break;
|
|
|
|
cf_node = next;
|
|
}
|
|
|
|
return stitch_blocks(block_before, block_after);
|
|
}
|
|
|
|
static void
|
|
relink_jump_halt_cf_node(nir_cf_node *node, nir_block *end_block)
|
|
{
|
|
switch (node->type) {
|
|
case nir_cf_node_block: {
|
|
nir_block *block = nir_cf_node_as_block(node);
|
|
nir_instr *last_instr = nir_block_last_instr(block);
|
|
if (last_instr == NULL || last_instr->type != nir_instr_type_jump)
|
|
break;
|
|
|
|
nir_jump_instr *jump = nir_instr_as_jump(last_instr);
|
|
/* We can't move a CF list from one function to another while we still
|
|
* have returns.
|
|
*/
|
|
assert(jump->type != nir_jump_return);
|
|
|
|
if (jump->type == nir_jump_halt) {
|
|
unlink_block_successors(block);
|
|
link_blocks(block, end_block, NULL);
|
|
}
|
|
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)
|
|
relink_jump_halt_cf_node(child, end_block);
|
|
foreach_list_typed(nir_cf_node, child, node, &if_stmt->else_list)
|
|
relink_jump_halt_cf_node(child, end_block);
|
|
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)
|
|
relink_jump_halt_cf_node(child, end_block);
|
|
break;
|
|
}
|
|
|
|
case nir_cf_node_function:
|
|
unreachable("Cannot insert a function in a function");
|
|
|
|
default:
|
|
unreachable("Invalid CF node type");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Inserts a list at a given cursor. Returns the cursor at the end of the
|
|
* insertion (i.e., at the end of the instructions contained in cf_list).
|
|
*/
|
|
nir_cursor
|
|
nir_cf_reinsert(nir_cf_list *cf_list, nir_cursor cursor)
|
|
{
|
|
nir_block *before, *after;
|
|
|
|
if (exec_list_is_empty(&cf_list->list))
|
|
return cursor;
|
|
|
|
nir_function_impl *cursor_impl =
|
|
nir_cf_node_get_function(&nir_cursor_current_block(cursor)->cf_node);
|
|
if (cf_list->impl != cursor_impl) {
|
|
foreach_list_typed(nir_cf_node, node, node, &cf_list->list)
|
|
relink_jump_halt_cf_node(node, cursor_impl->end_block);
|
|
}
|
|
|
|
split_block_cursor(cursor, &before, &after);
|
|
|
|
foreach_list_typed_safe(nir_cf_node, node, node, &cf_list->list) {
|
|
exec_node_remove(&node->node);
|
|
node->parent = before->cf_node.parent;
|
|
exec_node_insert_node_before(&after->cf_node.node, &node->node);
|
|
}
|
|
|
|
stitch_blocks(before,
|
|
nir_cf_node_as_block(nir_cf_node_next(&before->cf_node)));
|
|
return stitch_blocks(nir_cf_node_as_block(nir_cf_node_prev(&after->cf_node)),
|
|
after);
|
|
}
|
|
|
|
void
|
|
nir_cf_delete(nir_cf_list *cf_list)
|
|
{
|
|
foreach_list_typed(nir_cf_node, node, node, &cf_list->list) {
|
|
cleanup_cf_node(node, cf_list->impl);
|
|
}
|
|
}
|