[Mesa-dev] [PATCH 11/21] nir/cf: handle jumps in split_block_end()

[Connor Abbott]

Before, we would only split a block with a jump at the end if we were
inserting something after a block with a jump, which never happened in
practice. But now, we want to use this to extract control flow lists
which may end in a jump, in which case we really need to do the correct
patching up. As a side effect, when removing jumps we now correctly
insert undef phi sources in some corner cases, which can't hurt.

Signed-off-by: Connor Abbott <connor.w.abbott at intel.com>
---
 src/glsl/nir/nir_control_flow.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/glsl/nir/nir_control_flow.c b/src/glsl/nir/nir_control_flow.c
index b99bf89..1f2a681 100644
--- a/src/glsl/nir/nir_control_flow.c
+++ b/src/glsl/nir/nir_control_flow.c
@@ -363,7 +363,14 @@ split_block_end(nir_block *block)
    new_block->cf_node.parent = block->cf_node.parent;
    exec_node_insert_after(&block->cf_node.node, &new_block->cf_node.node);
 
-   move_successors(block, new_block);
+   if (block_ends_in_jump(block)) {
+      /* Figure out what successor block would've had if it didn't have a jump
+       * instruction, and make new_block have that successor.
+       */
+      block_add_normal_succs(new_block);
+   } else {
+      move_successors(block, new_block);
+   }
 
    return new_block;
 }
-- 
2.4.3