[PATCH v4 1/3] vkd3d-shader/ir: Move `continue's to the false branch when possible.

[Giovanni Mascellani]

From: Giovanni Mascellani

---
 libs/vkd3d-shader/ir.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/libs/vkd3d-shader/ir.c b/libs/vkd3d-shader/ir.c
index 4f0226187..5b8932a5f 100644
--- a/libs/vkd3d-shader/ir.c
+++ b/libs/vkd3d-shader/ir.c
@@ -4123,11 +4123,29 @@ static enum vkd3d_result vsir_cfg_build_structured_program(struct vsir_cfg *cfg)
                      * next block, in which case we make sure it's the
                      * false branch. */
                     if (action_true.jump_type == JUMP_NONE)
+                    {
+                        invert_condition = true;
+                    }
+                    else if (stack_depth >= 2)
+                    {
+                        struct vsir_cfg_structure_list *inner_loop_frame = stack[stack_depth - 2];
+                        struct vsir_cfg_structure *inner_loop = &inner_loop_frame->structures[inner_loop_frame->count - 1];
+
+                        assert(inner_loop->type == STRUCTURE_TYPE_LOOP);
+
+                        /* Otherwise, if one of the branches is
+                         * continueing the inner loop we're inside,
+                         * make sure it's the false branch (because it
+                         * will be optimized out later). */
+                        if (action_true.jump_type == JUMP_CONTINUE && action_true.target == inner_loop->u.loop.idx)
+                            invert_condition = true;
+                    }
+
+                    if (invert_condition)
                     {
                         struct vsir_cfg_edge_action tmp = action_true;
                         action_true = action_false;
                         action_false = tmp;
-                        invert_condition = true;
                     }

assert(action_true.jump_type != JUMP_NONE);