return true;
}
-static void
-vtn_add_case(struct vtn_builder *b, struct vtn_switch *swtch,
- struct vtn_block *break_block,
- uint32_t block_id, uint64_t val, bool is_default)
-{
- struct vtn_block *case_block = vtn_block(b, block_id);
-
- /* Don't create dummy cases that just break */
- if (case_block == break_block)
- return;
-
- if (case_block->switch_case == NULL) {
- struct vtn_case *c = ralloc(b, struct vtn_case);
-
- c->node.type = vtn_cf_node_type_case;
- c->node.parent = &swtch->node;
- list_inithead(&c->body);
- c->start_block = case_block;
- c->fallthrough = NULL;
- util_dynarray_init(&c->values, b);
- c->is_default = false;
- c->visited = false;
-
- list_addtail(&c->node.link, &swtch->cases);
-
- case_block->switch_case = c;
- }
-
- if (is_default) {
- case_block->switch_case->is_default = true;
- } else {
- util_dynarray_append(&case_block->switch_case->values, uint64_t, val);
- }
-}
-
/* This function performs a depth-first search of the cases and puts them
* in fall-through order.
*/
}
}
-static enum vtn_branch_type
-vtn_get_branch_type(struct vtn_builder *b,
- struct vtn_block *block,
- struct vtn_case *swcase, struct vtn_block *switch_break,
- struct vtn_block *loop_break, struct vtn_block *loop_cont)
+static void
+vtn_switch_order_cases(struct vtn_switch *swtch)
{
- if (block->switch_case) {
- /* This branch is actually a fallthrough */
- vtn_assert(swcase->fallthrough == NULL ||
- swcase->fallthrough == block->switch_case);
- swcase->fallthrough = block->switch_case;
- return vtn_branch_type_switch_fallthrough;
- } else if (block == loop_break) {
- return vtn_branch_type_loop_break;
- } else if (block == loop_cont) {
- return vtn_branch_type_loop_continue;
- } else if (block == switch_break) {
- return vtn_branch_type_switch_break;
- } else {
- return vtn_branch_type_none;
+ struct list_head cases;
+ list_replace(&swtch->cases, &cases);
+ list_inithead(&swtch->cases);
+ while (!list_is_empty(&cases)) {
+ struct vtn_case *cse =
+ list_first_entry(&cases, struct vtn_case, node.link);
+ vtn_order_case(swtch, cse);
}
}
static void
-vtn_cfg_walk_blocks(struct vtn_builder *b,
- struct vtn_cf_node *cf_parent,
- struct list_head *cf_list,
- struct vtn_block *start, struct vtn_case *switch_case,
- struct vtn_block *switch_break,
- struct vtn_block *loop_break, struct vtn_block *loop_cont,
- struct vtn_block *end)
+vtn_block_set_merge_cf_node(struct vtn_builder *b, struct vtn_block *block,
+ struct vtn_cf_node *cf_node)
{
- struct vtn_block *block = start;
- while (block != end) {
- if (block->merge && (*block->merge & SpvOpCodeMask) == SpvOpLoopMerge &&
- !block->loop) {
- struct vtn_loop *loop = ralloc(b, struct vtn_loop);
-
- loop->node.type = vtn_cf_node_type_loop;
- loop->node.parent = cf_parent;
- list_inithead(&loop->body);
- list_inithead(&loop->cont_body);
- loop->control = block->merge[3];
-
- list_addtail(&loop->node.link, cf_list);
- block->loop = loop;
-
- struct vtn_block *new_loop_break = vtn_block(b, block->merge[1]);
- struct vtn_block *new_loop_cont = vtn_block(b, block->merge[2]);
-
- /* Note: This recursive call will start with the current block as
- * its start block. If we weren't careful, we would get here
- * again and end up in infinite recursion. This is why we set
- * block->loop above and check for it before creating one. This
- * way, we only create the loop once and the second call that
- * tries to handle this loop goes to the cases below and gets
- * handled as a regular block.
- *
- * Note: When we make the recursive walk calls, we pass NULL for
- * the switch break since you have to break out of the loop first.
- * We do, however, still pass the current switch case because it's
- * possible that the merge block for the loop is the start of
- * another case.
- */
- vtn_cfg_walk_blocks(b, &loop->node, &loop->body,
- block, switch_case, NULL,
- new_loop_break, new_loop_cont, NULL );
- vtn_cfg_walk_blocks(b, &loop->node, &loop->cont_body,
- new_loop_cont, NULL, NULL,
- new_loop_break, NULL, block);
-
- enum vtn_branch_type branch_type =
- vtn_get_branch_type(b, new_loop_break, switch_case, switch_break,
- loop_break, loop_cont);
-
- if (branch_type != vtn_branch_type_none) {
- /* Stop walking through the CFG when this inner loop's break block
- * ends up as the same block as the outer loop's continue block
- * because we are already going to visit it.
- */
- vtn_assert(branch_type == vtn_branch_type_loop_continue);
- return;
+ vtn_fail_if(block->merge_cf_node != NULL,
+ "The merge block declared by a header block cannot be a "
+ "merge block declared by any other header block.");
+
+ block->merge_cf_node = cf_node;
+}
+
+#define VTN_DECL_CF_NODE_FIND(_type) \
+static inline struct vtn_##_type * \
+vtn_cf_node_find_##_type(struct vtn_cf_node *node) \
+{ \
+ while (node && node->type != vtn_cf_node_type_##_type) \
+ node = node->parent; \
+ return (struct vtn_##_type *)node; \
+}
+
+VTN_DECL_CF_NODE_FIND(if)
+VTN_DECL_CF_NODE_FIND(loop)
+VTN_DECL_CF_NODE_FIND(case)
+VTN_DECL_CF_NODE_FIND(switch)
+VTN_DECL_CF_NODE_FIND(function)
+
+static enum vtn_branch_type
+vtn_handle_branch(struct vtn_builder *b,
+ struct vtn_cf_node *cf_parent,
+ struct vtn_block *target_block)
+{
+ struct vtn_loop *loop = vtn_cf_node_find_loop(cf_parent);
+
+ /* Detect a loop back-edge first. That way none of the code below
+ * accidentally operates on a loop back-edge.
+ */
+ if (loop && target_block == loop->header_block)
+ return vtn_branch_type_loop_back_edge;
+
+ /* Try to detect fall-through */
+ if (target_block->switch_case) {
+ /* When it comes to handling switch cases, we can break calls to
+ * vtn_handle_branch into two cases: calls from within a case construct
+ * and calls for the jump to each case construct. In the second case,
+ * cf_parent is the vtn_switch itself and vtn_cf_node_find_case() will
+ * return the outer switch case in which this switch is contained. It's
+ * fine if the target block is a switch case from an outer switch as
+ * long as it is also the switch break for this switch.
+ */
+ struct vtn_case *switch_case = vtn_cf_node_find_case(cf_parent);
+
+ /* This doesn't get called for the OpSwitch */
+ vtn_fail_if(switch_case == NULL,
+ "A switch case can only be entered through an OpSwitch or "
+ "falling through from another switch case.");
+
+ /* Because block->switch_case is only set on the entry block for a given
+ * switch case, we only ever get here if we're jumping to the start of a
+ * switch case. It's possible, however, that a switch case could jump
+ * to itself via a back-edge. That *should* get caught by the loop
+ * handling case above but if we have a back edge without a loop merge,
+ * we could en up here.
+ */
+ vtn_fail_if(target_block->switch_case == switch_case,
+ "A switch cannot fall-through to itself. Likely, there is "
+ "a back-edge which is not to a loop header.");
+
+ vtn_fail_if(target_block->switch_case->node.parent !=
+ switch_case->node.parent,
+ "A switch case fall-through must come from the same "
+ "OpSwitch construct");
+
+ vtn_fail_if(switch_case->fallthrough != NULL &&
+ switch_case->fallthrough != target_block->switch_case,
+ "Each case construct can have at most one branch to "
+ "another case construct");
+
+ switch_case->fallthrough = target_block->switch_case;
+
+ /* We don't immediately return vtn_branch_type_switch_fallthrough
+ * because it may also be a loop or switch break for an inner loop or
+ * switch and that takes precedence.
+ */
+ }
+
+ if (loop && target_block == loop->cont_block)
+ return vtn_branch_type_loop_continue;
+
+ /* We walk blocks as a breadth-first search on the control-flow construct
+ * tree where, when we find a construct, we add the vtn_cf_node for that
+ * construct and continue iterating at the merge target block (if any).
+ * Therefore, we want merges whose with parent == cf_parent to be treated
+ * as regular branches. We only want to consider merges if they break out
+ * of the current CF construct.
+ */
+ if (target_block->merge_cf_node != NULL &&
+ target_block->merge_cf_node->parent != cf_parent) {
+ switch (target_block->merge_cf_node->type) {
+ case vtn_cf_node_type_if:
+ for (struct vtn_cf_node *node = cf_parent;
+ node != target_block->merge_cf_node; node = node->parent) {
+ vtn_fail_if(node == NULL || node->type != vtn_cf_node_type_if,
+ "Branching to the merge block of a selection "
+ "construct can only be used to break out of a "
+ "selection construct");
+
+ struct vtn_if *if_stmt = vtn_cf_node_as_if(node);
+
+ /* This should be guaranteed by our iteration */
+ assert(if_stmt->merge_block != target_block);
+
+ vtn_fail_if(if_stmt->merge_block != NULL,
+ "Branching to the merge block of a selection "
+ "construct can only be used to break out of the "
+ "inner most nested selection level");
}
+ return vtn_branch_type_if_merge;
- block = new_loop_break;
- continue;
+ case vtn_cf_node_type_loop:
+ vtn_fail_if(target_block->merge_cf_node != &loop->node,
+ "Loop breaks can only break out of the inner most "
+ "nested loop level");
+ return vtn_branch_type_loop_break;
+
+ case vtn_cf_node_type_switch: {
+ struct vtn_switch *swtch = vtn_cf_node_find_switch(cf_parent);
+ vtn_fail_if(target_block->merge_cf_node != &swtch->node,
+ "Switch breaks can only break out of the inner most "
+ "nested switch level");
+ return vtn_branch_type_switch_break;
}
- vtn_assert(block->node.link.next == NULL);
- block->node.parent = cf_parent;
- list_addtail(&block->node.link, cf_list);
+ default:
+ unreachable("Invalid CF node type for a merge");
+ }
+ }
- switch (*block->branch & SpvOpCodeMask) {
- case SpvOpBranch: {
- struct vtn_block *branch_block = vtn_block(b, block->branch[1]);
+ if (target_block->switch_case)
+ return vtn_branch_type_switch_fallthrough;
- block->branch_type = vtn_get_branch_type(b, branch_block,
- switch_case, switch_break,
- loop_break, loop_cont);
+ return vtn_branch_type_none;
+}
- if (block->branch_type != vtn_branch_type_none)
- return;
+struct vtn_cfg_work_item {
+ struct list_head link;
- block = branch_block;
- continue;
+ struct vtn_cf_node *cf_parent;
+ struct list_head *cf_list;
+ struct vtn_block *start_block;
+};
+
+static void
+vtn_add_cfg_work_item(struct vtn_builder *b,
+ struct list_head *work_list,
+ struct vtn_cf_node *cf_parent,
+ struct list_head *cf_list,
+ struct vtn_block *start_block)
+{
+ struct vtn_cfg_work_item *work = ralloc(b, struct vtn_cfg_work_item);
+ work->cf_parent = cf_parent;
+ work->cf_list = cf_list;
+ work->start_block = start_block;
+ list_addtail(&work->link, work_list);
+}
+
+/* Processes a block and returns the next block to process or NULL if we've
+ * reached the end of the construct.
+ */
+static struct vtn_block *
+vtn_process_block(struct vtn_builder *b,
+ struct list_head *work_list,
+ struct vtn_cf_node *cf_parent,
+ struct list_head *cf_list,
+ struct vtn_block *block)
+{
+ if (!list_is_empty(cf_list)) {
+ /* vtn_process_block() acts like an iterator: it processes the given
+ * block and then returns the next block to process. For a given
+ * control-flow construct, vtn_build_cfg() calls vtn_process_block()
+ * repeatedly until it finally returns NULL. Therefore, we know that
+ * the only blocks on which vtn_process_block() can be called are either
+ * the first block in a construct or a block that vtn_process_block()
+ * returned for the current construct. If cf_list is empty then we know
+ * that we're processing the first block in the construct and we have to
+ * add it to the list.
+ *
+ * If cf_list is not empty, then it must be the block returned by the
+ * previous call to vtn_process_block(). We know a priori that
+ * vtn_process_block only returns either normal branches
+ * (vtn_branch_type_none) or merge target blocks.
+ */
+ switch (vtn_handle_branch(b, cf_parent, block)) {
+ case vtn_branch_type_none:
+ /* For normal branches, we want to process them and add them to the
+ * current construct. Merge target blocks also look like normal
+ * branches from the perspective of this construct. See also
+ * vtn_handle_branch().
+ */
+ break;
+
+ case vtn_branch_type_loop_continue:
+ case vtn_branch_type_switch_fallthrough:
+ /* The two cases where we can get early exits from a construct that
+ * are not to that construct's merge target are loop continues and
+ * switch fall-throughs. In these cases, we need to break out of the
+ * current construct by returning NULL.
+ */
+ return NULL;
+
+ default:
+ /* The only way we can get here is if something was used as two kinds
+ * of merges at the same time and that's illegal.
+ */
+ vtn_fail("A block was used as a merge target from two or more "
+ "structured control-flow constructs");
}
+ }
- case SpvOpReturn:
- case SpvOpReturnValue:
- block->branch_type = vtn_branch_type_return;
- return;
+ /* Once a block has been processed, it is placed into and the list link
+ * will point to something non-null. If we see a node we've already
+ * processed here, it either exists in multiple functions or it's an
+ * invalid back-edge.
+ */
+ if (block->node.parent != NULL) {
+ vtn_fail_if(vtn_cf_node_find_function(&block->node) !=
+ vtn_cf_node_find_function(cf_parent),
+ "A block cannot exist in two functions at the "
+ "same time");
- case SpvOpKill:
- block->branch_type = vtn_branch_type_discard;
- return;
+ vtn_fail("Invalid back or cross-edge in the CFG");
+ }
- case SpvOpBranchConditional: {
- struct vtn_block *then_block = vtn_block(b, block->branch[2]);
- struct vtn_block *else_block = vtn_block(b, block->branch[3]);
+ if (block->merge && (*block->merge & SpvOpCodeMask) == SpvOpLoopMerge &&
+ block->loop == NULL) {
+ vtn_fail_if((*block->branch & SpvOpCodeMask) != SpvOpBranch &&
+ (*block->branch & SpvOpCodeMask) != SpvOpBranchConditional,
+ "An OpLoopMerge instruction must immediately precede "
+ "either an OpBranch or OpBranchConditional instruction.");
+
+ struct vtn_loop *loop = rzalloc(b, struct vtn_loop);
+
+ loop->node.type = vtn_cf_node_type_loop;
+ loop->node.parent = cf_parent;
+ list_inithead(&loop->body);
+ list_inithead(&loop->cont_body);
+ loop->header_block = block;
+ loop->break_block = vtn_block(b, block->merge[1]);
+ loop->cont_block = vtn_block(b, block->merge[2]);
+ loop->control = block->merge[3];
+
+ list_addtail(&loop->node.link, cf_list);
+ block->loop = loop;
+
+ /* Note: The work item for the main loop body will start with the
+ * current block as its start block. If we weren't careful, we would
+ * get here again and end up in an infinite loop. This is why we set
+ * block->loop above and check for it before creating one. This way,
+ * we only create the loop once and the second iteration that tries to
+ * handle this loop goes to the cases below and gets handled as a
+ * regular block.
+ */
+ vtn_add_cfg_work_item(b, work_list, &loop->node,
+ &loop->body, loop->header_block);
+
+ /* For continue targets, SPIR-V guarantees the following:
+ *
+ * - the Continue Target must dominate the back-edge block
+ * - the back-edge block must post dominate the Continue Target
+ *
+ * If the header block is the same as the continue target, this
+ * condition is trivially satisfied and there is no real continue
+ * section.
+ */
+ if (loop->cont_block != loop->header_block) {
+ vtn_add_cfg_work_item(b, work_list, &loop->node,
+ &loop->cont_body, loop->cont_block);
+ }
- struct vtn_if *if_stmt = ralloc(b, struct vtn_if);
+ vtn_block_set_merge_cf_node(b, loop->break_block, &loop->node);
- if_stmt->node.type = vtn_cf_node_type_if;
- if_stmt->node.parent = cf_parent;
- if_stmt->condition = block->branch[1];
- list_inithead(&if_stmt->then_body);
- list_inithead(&if_stmt->else_body);
+ return loop->break_block;
+ }
- list_addtail(&if_stmt->node.link, cf_list);
+ /* Add the block to the CF list */
+ block->node.parent = cf_parent;
+ list_addtail(&block->node.link, cf_list);
- if (block->merge &&
- (*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge) {
- if_stmt->control = block->merge[2];
- } else {
- if_stmt->control = SpvSelectionControlMaskNone;
- }
+ switch (*block->branch & SpvOpCodeMask) {
+ case SpvOpBranch: {
+ struct vtn_block *branch_block = vtn_block(b, block->branch[1]);
- if_stmt->then_type = vtn_get_branch_type(b, then_block,
- switch_case, switch_break,
- loop_break, loop_cont);
- if_stmt->else_type = vtn_get_branch_type(b, else_block,
- switch_case, switch_break,
- loop_break, loop_cont);
-
- if (then_block == else_block) {
- block->branch_type = if_stmt->then_type;
- if (block->branch_type == vtn_branch_type_none) {
- block = then_block;
- continue;
- } else {
- return;
- }
- } else if (if_stmt->then_type == vtn_branch_type_none &&
- if_stmt->else_type == vtn_branch_type_none) {
- /* Neither side of the if is something we can short-circuit. */
- vtn_assert((*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge);
- struct vtn_block *merge_block = vtn_block(b, block->merge[1]);
-
- vtn_cfg_walk_blocks(b, &if_stmt->node, &if_stmt->then_body,
- then_block, switch_case, switch_break,
- loop_break, loop_cont, merge_block);
- vtn_cfg_walk_blocks(b, &if_stmt->node, &if_stmt->else_body,
- else_block, switch_case, switch_break,
- loop_break, loop_cont, merge_block);
-
- enum vtn_branch_type merge_type =
- vtn_get_branch_type(b, merge_block, switch_case, switch_break,
- loop_break, loop_cont);
- if (merge_type == vtn_branch_type_none) {
- block = merge_block;
- continue;
- } else {
- return;
- }
- } else if (if_stmt->then_type != vtn_branch_type_none &&
- if_stmt->else_type != vtn_branch_type_none) {
- /* Both sides were short-circuited. We're done here. */
- return;
- } else {
- /* Exeactly one side of the branch could be short-circuited.
- * We set the branch up as a predicated break/continue and we
- * continue on with the other side as if it were what comes
- * after the if.
- */
- if (if_stmt->then_type == vtn_branch_type_none) {
- block = then_block;
- } else {
- block = else_block;
- }
- continue;
- }
- vtn_fail("Should have returned or continued");
+ block->branch_type = vtn_handle_branch(b, cf_parent, branch_block);
+
+ if (block->branch_type == vtn_branch_type_none)
+ return branch_block;
+ else
+ return NULL;
+ }
+
+ case SpvOpReturn:
+ case SpvOpReturnValue:
+ block->branch_type = vtn_branch_type_return;
+ return NULL;
+
+ case SpvOpKill:
+ block->branch_type = vtn_branch_type_discard;
+ return NULL;
+
+ case SpvOpBranchConditional: {
+ struct vtn_value *cond_val = vtn_untyped_value(b, block->branch[1]);
+ vtn_fail_if(!cond_val->type ||
+ cond_val->type->base_type != vtn_base_type_scalar ||
+ cond_val->type->type != glsl_bool_type(),
+ "Condition must be a Boolean type scalar");
+
+ struct vtn_block *then_block = vtn_block(b, block->branch[2]);
+ struct vtn_block *else_block = vtn_block(b, block->branch[3]);
+
+ if (then_block == else_block) {
+ /* This is uncommon but it can happen. We treat this the same way as
+ * an unconditional branch.
+ */
+ block->branch_type = vtn_handle_branch(b, cf_parent, then_block);
+
+ if (block->branch_type == vtn_branch_type_none)
+ return then_block;
+ else
+ return NULL;
}
- case SpvOpSwitch: {
- vtn_assert((*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge);
- struct vtn_block *break_block = vtn_block(b, block->merge[1]);
-
- struct vtn_switch *swtch = ralloc(b, struct vtn_switch);
-
- swtch->node.type = vtn_cf_node_type_switch;
- swtch->node.parent = cf_parent;
- swtch->selector = block->branch[1];
- list_inithead(&swtch->cases);
-
- list_addtail(&swtch->node.link, cf_list);
-
- /* First, we go through and record all of the cases. */
- const uint32_t *branch_end =
- block->branch + (block->branch[0] >> SpvWordCountShift);
-
- struct vtn_value *cond_val = vtn_untyped_value(b, block->branch[1]);
- vtn_fail_if(!cond_val->type ||
- cond_val->type->base_type != vtn_base_type_scalar,
- "Selector of OpSelect must have a type of OpTypeInt");
-
- nir_alu_type cond_type =
- nir_get_nir_type_for_glsl_type(cond_val->type->type);
- vtn_fail_if(nir_alu_type_get_base_type(cond_type) != nir_type_int &&
- nir_alu_type_get_base_type(cond_type) != nir_type_uint,
- "Selector of OpSelect must have a type of OpTypeInt");
-
- bool is_default = true;
- const unsigned bitsize = nir_alu_type_get_type_size(cond_type);
- for (const uint32_t *w = block->branch + 2; w < branch_end;) {
- uint64_t literal = 0;
- if (!is_default) {
- if (bitsize <= 32) {
- literal = *(w++);
- } else {
- assert(bitsize == 64);
- literal = vtn_u64_literal(w);
- w += 2;
- }
- }
+ struct vtn_if *if_stmt = rzalloc(b, struct vtn_if);
- uint32_t block_id = *(w++);
+ if_stmt->node.type = vtn_cf_node_type_if;
+ if_stmt->node.parent = cf_parent;
+ if_stmt->condition = block->branch[1];
+ list_inithead(&if_stmt->then_body);
+ list_inithead(&if_stmt->else_body);
- vtn_add_case(b, swtch, break_block, block_id, literal, is_default);
- is_default = false;
- }
+ list_addtail(&if_stmt->node.link, cf_list);
- /* Now, we go through and walk the blocks. While we walk through
- * the blocks, we also gather the much-needed fall-through
- * information.
+ if (block->merge &&
+ (*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge) {
+ /* We may not always have a merge block and that merge doesn't
+ * technically have to be an OpSelectionMerge. We could have a block
+ * with an OpLoopMerge which ends in an OpBranchConditional.
*/
- vtn_foreach_cf_node(case_node, &swtch->cases) {
- struct vtn_case *cse = vtn_cf_node_as_case(case_node);
- vtn_assert(cse->start_block != break_block);
- vtn_cfg_walk_blocks(b, &cse->node, &cse->body, cse->start_block,
- cse, break_block, loop_break, loop_cont, NULL);
- }
+ if_stmt->merge_block = vtn_block(b, block->merge[1]);
+ vtn_block_set_merge_cf_node(b, if_stmt->merge_block, &if_stmt->node);
- /* Finally, we walk over all of the cases one more time and put
- * them in fall-through order.
- */
- for (const uint32_t *w = block->branch + 2; w < branch_end;) {
- struct vtn_block *case_block = vtn_block(b, *w);
+ if_stmt->control = block->merge[2];
+ }
+
+ if_stmt->then_type = vtn_handle_branch(b, &if_stmt->node, then_block);
+ if (if_stmt->then_type == vtn_branch_type_none) {
+ vtn_add_cfg_work_item(b, work_list, &if_stmt->node,
+ &if_stmt->then_body, then_block);
+ }
+
+ if_stmt->else_type = vtn_handle_branch(b, &if_stmt->node, else_block);
+ if (if_stmt->else_type == vtn_branch_type_none) {
+ vtn_add_cfg_work_item(b, work_list, &if_stmt->node,
+ &if_stmt->else_body, else_block);
+ }
+
+ return if_stmt->merge_block;
+ }
+
+ case SpvOpSwitch: {
+ struct vtn_value *sel_val = vtn_untyped_value(b, block->branch[1]);
+ vtn_fail_if(!sel_val->type ||
+ sel_val->type->base_type != vtn_base_type_scalar,
+ "Selector of OpSwitch must have a type of OpTypeInt");
+
+ nir_alu_type sel_type =
+ nir_get_nir_type_for_glsl_type(sel_val->type->type);
+ vtn_fail_if(nir_alu_type_get_base_type(sel_type) != nir_type_int &&
+ nir_alu_type_get_base_type(sel_type) != nir_type_uint,
+ "Selector of OpSwitch must have a type of OpTypeInt");
+
+ struct vtn_switch *swtch = rzalloc(b, struct vtn_switch);
+
+ swtch->node.type = vtn_cf_node_type_switch;
+ swtch->node.parent = cf_parent;
+ swtch->selector = block->branch[1];
+ list_inithead(&swtch->cases);
+
+ list_addtail(&swtch->node.link, cf_list);
+
+ /* We may not always have a merge block */
+ if (block->merge) {
+ vtn_fail_if((*block->merge & SpvOpCodeMask) != SpvOpSelectionMerge,
+ "An OpLoopMerge instruction must immediately precede "
+ "either an OpBranch or OpBranchConditional "
+ "instruction.");
+ swtch->break_block = vtn_block(b, block->merge[1]);
+ vtn_block_set_merge_cf_node(b, swtch->break_block, &swtch->node);
+ }
+
+ /* First, we go through and record all of the cases. */
+ const uint32_t *branch_end =
+ block->branch + (block->branch[0] >> SpvWordCountShift);
+
+ struct hash_table *block_to_case = _mesa_pointer_hash_table_create(b);
+ bool is_default = true;
+ const unsigned bitsize = nir_alu_type_get_type_size(sel_type);
+ for (const uint32_t *w = block->branch + 2; w < branch_end;) {
+ uint64_t literal = 0;
+ if (!is_default) {
if (bitsize <= 32) {
- w += 2;
+ literal = *(w++);
} else {
assert(bitsize == 64);
- w += 3;
+ literal = vtn_u64_literal(w);
+ w += 2;
}
+ }
+ struct vtn_block *case_block = vtn_block(b, *(w++));
- if (case_block == break_block)
- continue;
+ struct hash_entry *case_entry =
+ _mesa_hash_table_search(block_to_case, case_block);
- vtn_assert(case_block->switch_case);
+ struct vtn_case *cse;
+ if (case_entry) {
+ cse = case_entry->data;
+ } else {
+ cse = rzalloc(b, struct vtn_case);
+
+ cse->node.type = vtn_cf_node_type_case;
+ cse->node.parent = &swtch->node;
+ list_inithead(&cse->body);
+ util_dynarray_init(&cse->values, b);
+
+ cse->type = vtn_handle_branch(b, &swtch->node, case_block);
+ switch (cse->type) {
+ case vtn_branch_type_none:
+ /* This is a "real" cases which has stuff in it */
+ vtn_fail_if(case_block->switch_case != NULL,
+ "OpSwitch has a case which is also in another "
+ "OpSwitch construct");
+ case_block->switch_case = cse;
+ vtn_add_cfg_work_item(b, work_list, &cse->node,
+ &cse->body, case_block);
+ break;
+
+ case vtn_branch_type_switch_break:
+ case vtn_branch_type_loop_break:
+ case vtn_branch_type_loop_continue:
+ /* Switch breaks as well as loop breaks and continues can be
+ * used to break out of a switch construct or as direct targets
+ * of the OpSwitch.
+ */
+ break;
+
+ default:
+ vtn_fail("Target of OpSwitch is not a valid structured exit "
+ "from the switch construct.");
+ }
- vtn_order_case(swtch, case_block->switch_case);
- }
+ list_addtail(&cse->node.link, &swtch->cases);
- enum vtn_branch_type branch_type =
- vtn_get_branch_type(b, break_block, switch_case, NULL,
- loop_break, loop_cont);
+ _mesa_hash_table_insert(block_to_case, case_block, cse);
+ }
- if (branch_type != vtn_branch_type_none) {
- /* It is possible that the break is actually the continue block
- * for the containing loop. In this case, we need to bail and let
- * the loop parsing code handle the continue properly.
- */
- vtn_assert(branch_type == vtn_branch_type_loop_continue);
- return;
+ if (is_default) {
+ cse->is_default = true;
+ } else {
+ util_dynarray_append(&cse->values, uint64_t, literal);
}
- block = break_block;
- continue;
+ is_default = false;
}
- case SpvOpUnreachable:
- return;
+ _mesa_hash_table_destroy(block_to_case, NULL);
- default:
- vtn_fail("Unhandled opcode");
- }
+ return swtch->break_block;
+ }
+
+ case SpvOpUnreachable:
+ return NULL;
+
+ default:
+ vtn_fail("Block did not end with a valid branch instruction");
}
}
vtn_foreach_instruction(b, words, end,
vtn_cfg_handle_prepass_instruction);
- vtn_foreach_cf_node(node, &b->functions) {
- struct vtn_function *func = vtn_cf_node_as_function(node);
- vtn_cfg_walk_blocks(b, &func->node, &func->body, func->start_block,
- NULL, NULL, NULL, NULL, NULL);
+ vtn_foreach_cf_node(func_node, &b->functions) {
+ struct vtn_function *func = vtn_cf_node_as_function(func_node);
+
+ /* We build the CFG for each function by doing a breadth-first search on
+ * the control-flow graph. We keep track of our state using a worklist.
+ * Doing a BFS ensures that we visit each structured control-flow
+ * construct and its merge node before we visit the stuff inside the
+ * construct.
+ */
+ struct list_head work_list;
+ list_inithead(&work_list);
+ vtn_add_cfg_work_item(b, &work_list, &func->node, &func->body,
+ func->start_block);
+
+ while (!list_is_empty(&work_list)) {
+ struct vtn_cfg_work_item *work =
+ list_first_entry(&work_list, struct vtn_cfg_work_item, link);
+ list_del(&work->link);
+
+ for (struct vtn_block *block = work->start_block; block; ) {
+ block = vtn_process_block(b, &work_list, work->cf_parent,
+ work->cf_list, block);
+ }
+ }
}
}
nir_variable *switch_fall_var, bool *has_switch_break)
{
switch (branch_type) {
+ case vtn_branch_type_if_merge:
+ break; /* Nothing to do */
case vtn_branch_type_switch_break:
nir_store_var(&b->nb, switch_fall_var, nir_imm_false(&b->nb), 1);
*has_switch_break = true;
case vtn_branch_type_loop_continue:
nir_jump(&b->nb, nir_jump_continue);
break;
+ case vtn_branch_type_loop_back_edge:
+ break;
case vtn_branch_type_return:
nir_jump(&b->nb, nir_jump_return);
break;
case vtn_cf_node_type_switch: {
struct vtn_switch *vtn_switch = vtn_cf_node_as_switch(node);
+ /* Before we can emit anything, we need to sort the list of cases in
+ * fall-through order.
+ */
+ vtn_switch_order_cases(vtn_switch);
+
/* First, we create a variable to keep track of whether or not the
* switch is still going at any given point. Any switch breaks
* will set this variable to false.
projects / mesa.git / commitdiff