The previous fix restricted external vector builds to defs from
the same basic-block. That turns out too restrictive so we have
to mitigate the original issue in a different way which is
restricting it to the original case where all defs are in the
same basic-block.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/116352
* tree-vect-slp.cc (vect_build_slp_tree_2): When compressing
operands from a two-operator node make sure the resulting
operation does not mix defs from different basic-blocks.
---
gcc/tree-vect-slp.cc | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 6d5824a97bf..f7c51b6cf68 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -2619,13 +2619,14 @@ out:
if (oprnds_info[0]->def_stmts[0]
&& is_a<gassign *> (oprnds_info[0]->def_stmts[0]->stmt))
code = gimple_assign_rhs_code (oprnds_info[0]->def_stmts[0]->stmt);
+ basic_block bb = nullptr;
for (unsigned j = 0; j < group_size; ++j)
{
FOR_EACH_VEC_ELT (oprnds_info, i, oprnd_info)
{
stmt_vec_info stmt_info = oprnd_info->def_stmts[j];
- if (!stmt_info || !stmt_info->stmt
+ if (!stmt_info
|| !is_a<gassign *> (stmt_info->stmt)
|| gimple_assign_rhs_code (stmt_info->stmt) != code
|| skip_args[i])
@@ -2633,6 +2634,14 @@ out:
success = false;
break;
}
+ /* Avoid mixing lanes with defs in different basic-blocks. */
+ if (!bb)
+ bb = gimple_bb (vect_orig_stmt (stmt_info)->stmt);
+ else if (gimple_bb (vect_orig_stmt (stmt_info)->stmt) != bb)
+ {
+ success = false;
+ break;
+ }
bool exists;
unsigned &stmt_idx
--
2.43.0
