nir: keep the phi order when splitting blocks

All things being equal is better to keep the original order.  Since
the new block is empty, push the phis in order to tail.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Schürmann <daniel.schuermann@campus.tu-berlin.de>

diff --git a/src/compiler/nir/nir_control_flow.c b/src/compiler/nir/nir_control_flow.c
index ddba2e55b45c9433d3064eaee915249b2debd7eb..252aaf335ad3dfb0eca21cedbc6e35e2a40febbe 100644 (file)
--- a/src/compiler/nir/nir_control_flow.c
+++ b/src/compiler/nir/nir_control_flow.c
@@ -195,8 +195,7 @@ split_block_beginning(nir_block *block)
    }
 
    /* Any phi nodes must stay part of the new block, or else their
-    * sourcse will be messed up. This will reverse the order of the phis, but
-    * order shouldn't matter.
+    * sources will be messed up.
     */
    nir_foreach_instr_safe(instr, block) {
       if (instr->type != nir_instr_type_phi)
@@ -204,7 +203,7 @@ split_block_beginning(nir_block *block)
 
       exec_node_remove(&instr->node);
       instr->block = new_block;
-      exec_list_push_head(&new_block->instr_list, &instr->node);
+      exec_list_push_tail(&new_block->instr_list, &instr->node);
    }
 
    return new_block;