nir/spirv/cfg: Detect switch_break after loop_break/continue

While the current CFG code is valid in the case where a switch break also
happens to be a loop continue, it's a bit suboptimal.  Since hardware is
capable of handling the continue as a direct jump, it's better to use a
continue instruction when we can than to bother with all of the nasty
switch break lowering.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: "12.0" <mesa-stable@lists.freedesktop.org>

diff --git a/src/compiler/spirv/vtn_cfg.c b/src/compiler/spirv/vtn_cfg.c
index 475454e..1c8c4f8 100644 (file)
--- a/src/compiler/spirv/vtn_cfg.c
+++ b/src/compiler/spirv/vtn_cfg.c
@@ -239,12 +239,12 @@ vtn_get_branch_type(struct vtn_block *block,
              swcase->fallthrough == block->switch_case);
       swcase->fallthrough = block->switch_case;
       return vtn_branch_type_switch_fallthrough;
-   } else if (block == switch_break) {
-      return vtn_branch_type_switch_break;
    } 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;
    }