diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/compiler/nir/nir_control_flow.c | 59 |
1 files changed, 2 insertions, 57 deletions
diff --git a/src/compiler/nir/nir_control_flow.c b/src/compiler/nir/nir_control_flow.c index a485e713fa4..05cc9e95a1e 100644 --- a/src/compiler/nir/nir_control_flow.c +++ b/src/compiler/nir/nir_control_flow.c @@ -39,8 +39,6 @@ * 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. @@ -135,25 +133,6 @@ link_non_block_to_block(nir_cf_node *node, nir_block *block) } } 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); } } @@ -520,13 +499,6 @@ nir_handle_add_jump(nir_block *block) 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); @@ -551,8 +523,8 @@ remove_phi_src(nir_block *block, nir_block *pred) } } -/* Removes the successor of a block with a jump, and inserts a fake edge for - * infinite loops. Note that the jump to be eliminated may be free-floating. +/* Removes the successor of a block with a jump. Note that the jump to be + * eliminated may be free-floating. */ static void @@ -568,33 +540,6 @@ unlink_jump(nir_block *block, nir_jump_type type, bool add_normal_successors) unlink_block_successors(block); if (add_normal_successors) block_add_normal_succs(block); - - /* If we've just removed a break, and the block we were jumping to (after - * the loop) now has zero predecessors, we've created a new infinite loop. - * - * NIR doesn't allow blocks (other than the start block) to have zero - * predecessors. In particular, dominance assumes all blocks are reachable. - * So, we insert a "fake link" by making successors[1] point after the loop. - * - * Note that we have to do this after unlinking/recreating the block's - * successors. If we removed a "break" at the end of the loop, then - * block == last_block, so block->successors[0] would already be "next", - * and adding a fake link would create two identical successors. Doing - * this afterward works, as we'll have changed block->successors[0] to - * be the top of the loop. - */ - if (type == nir_jump_break && next->predecessors->entries == 0) { - nir_loop *loop = - nir_cf_node_as_loop(nir_cf_node_prev(&next->cf_node)); - - /* 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_add_pred(next, last_block); - } } void |