[PATCH] tree-optimization/95717 - fix SSA update for vectorizer epilogue
Richard Biener
rguenther@suse.de
Wed Jun 17 13:02:25 GMT 2020
This fixes yet another issue with the custom SSA updating in the
vectorizer when we copy from the non-if-converted loop. We must
not mess with current defs before we updated the BB copies.
Bootstrapped / tested on x86_64-unknown-linux-gnu, applied.
2020-06-17 Richard Biener <rguenther@suse.de>
PR tree-optimization/95717
* tree-vect-loop-manip.c (slpeel_tree_duplicate_loop_to_edge_cfg):
Move BB SSA updating before exit/latch PHI current def copying.
* g++.dg/torture/pr95717.C: New testcase.
---
gcc/testsuite/g++.dg/torture/pr95717.C | 12 ++++++++++++
gcc/tree-vect-loop-manip.c | 8 ++++----
2 files changed, 16 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/torture/pr95717.C
diff --git a/gcc/testsuite/g++.dg/torture/pr95717.C b/gcc/testsuite/g++.dg/torture/pr95717.C
new file mode 100644
index 00000000000..362dc10656b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr95717.C
@@ -0,0 +1,12 @@
+// { dg-do compile }
+
+bool a;
+extern bool b[];
+long c, d;
+int *f;
+void g(bool h)
+{
+ for (short e = 0; e < c; e = 4)
+ for (; d; d++)
+ b[d] = a = f[d] ? c ? h : 0 : h;
+}
diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c
index 458a6675c47..169ea64fd9e 100644
--- a/gcc/tree-vect-loop-manip.c
+++ b/gcc/tree-vect-loop-manip.c
@@ -1053,6 +1053,10 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop,
add_phi_args_after_copy (new_bbs, scalar_loop->num_nodes + 1, NULL);
+ /* Skip new preheader since it's deleted if copy loop is added at entry. */
+ for (unsigned i = (at_exit ? 0 : 1); i < scalar_loop->num_nodes + 1; i++)
+ rename_variables_in_bb (new_bbs[i], duplicate_outer_loop);
+
if (scalar_loop != loop)
{
/* If we copied from SCALAR_LOOP rather than LOOP, SSA_NAMEs from
@@ -1130,10 +1134,6 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop,
loop_preheader_edge (new_loop)->src);
}
- /* Skip new preheader since it's deleted if copy loop is added at entry. */
- for (unsigned i = (at_exit ? 0 : 1); i < scalar_loop->num_nodes + 1; i++)
- rename_variables_in_bb (new_bbs[i], duplicate_outer_loop);
-
if (scalar_loop != loop)
{
/* Update new_loop->header PHIs, so that on the preheader
--
2.26.2
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