* then we should prefer to not flatten the if/else..
*/
-struct lower_state {
- nir_builder b;
- void *mem_ctx;
- bool progress;
-};
-
static bool
valid_dest(nir_block *block, nir_dest *dest)
{
}
static bool
-lower_if_else_block(nir_block *block, void *void_state)
+lower_if_else_block(nir_block *block, nir_builder *b, void *mem_ctx)
{
- struct lower_state *state = void_state;
-
/* If the block is empty, then it certainly doesn't have any phi nodes,
* so we can skip it. This also ensures that we do an early skip on the
* end block of the function which isn't actually attached to the CFG.
*/
if (exec_list_is_empty(&block->instr_list))
- return true;
+ return false;
if (nir_cf_node_is_first(&block->cf_node))
- return true;
+ return false;
nir_cf_node *prev_node = nir_cf_node_prev(&block->cf_node);
if (prev_node->type != nir_cf_node_if)
- return true;
+ return false;
nir_if *if_stmt = nir_cf_node_as_if(prev_node);
nir_cf_node *then_node = nir_if_first_then_node(if_stmt);
/* We can only have one block in each side ... */
if (nir_if_last_then_node(if_stmt) != then_node ||
nir_if_last_else_node(if_stmt) != else_node)
- return true;
+ return false;
nir_block *then_block = nir_cf_node_as_block(then_node);
nir_block *else_block = nir_cf_node_as_block(else_node);
/* ... and those blocks must only contain "allowed" instructions. */
if (!block_check_for_allowed_instrs(then_block) ||
!block_check_for_allowed_instrs(else_block))
- return true;
+ return false;
/* condition should be ssa too, which simplifies flatten_block: */
if (!if_stmt->condition.is_ssa)
- return true;
+ return false;
/* At this point, we know that the previous CFG node is an if-then
* statement containing only moves to phi nodes in this block. We can
* block before. There are a few things that need handling specially
* like discard/discard_if.
*/
- flatten_block(&state->b, then_block, prev_block,
+ flatten_block(b, then_block, prev_block,
if_stmt->condition.ssa, false);
- flatten_block(&state->b, else_block, prev_block,
+ flatten_block(b, else_block, prev_block,
if_stmt->condition.ssa, true);
nir_foreach_instr_safe(instr, block) {
break;
nir_phi_instr *phi = nir_instr_as_phi(instr);
- nir_alu_instr *sel = nir_alu_instr_create(state->mem_ctx, nir_op_bcsel);
- nir_src_copy(&sel->src[0].src, &if_stmt->condition, state->mem_ctx);
+ nir_alu_instr *sel = nir_alu_instr_create(mem_ctx, nir_op_bcsel);
+ nir_src_copy(&sel->src[0].src, &if_stmt->condition, mem_ctx);
/* Splat the condition to all channels */
memset(sel->src[0].swizzle, 0, sizeof sel->src[0].swizzle);
assert(src->src.is_ssa);
unsigned idx = src->pred == then_block ? 1 : 2;
- nir_src_copy(&sel->src[idx].src, &src->src, state->mem_ctx);
+ nir_src_copy(&sel->src[idx].src, &src->src, mem_ctx);
}
nir_ssa_dest_init(&sel->instr, &sel->dest.dest,
}
nir_cf_node_remove(&if_stmt->cf_node);
- state->progress = true;
-
return true;
}
static bool
lower_if_else_impl(nir_function_impl *impl)
{
- struct lower_state state;
-
- state.mem_ctx = ralloc_parent(impl);
- state.progress = false;
- nir_builder_init(&state.b, impl);
+ void *mem_ctx = ralloc_parent(impl);
+ nir_builder b;
+ nir_builder_init(&b, impl);
- nir_foreach_block_call(impl, lower_if_else_block, &state);
+ bool progress = false;
+ nir_foreach_block(block, impl) {
+ progress |= lower_if_else_block(block, &b, mem_ctx);
+ }
- if (state.progress)
+ if (progress)
nir_metadata_preserve(impl, nir_metadata_none);
- return state.progress;
+ return progress;
}
bool