From: Richard Biener <rguenther@suse.de>
Date: Mon, 20 Feb 2023 09:59:15 +0000 (+0100)
Subject: tree-optimization/108816 - vect versioning check split confusion
X-Git-Tag: releases/gcc-12.3.0~256
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=02ff8c8ebcb7f9b0885946d17ff12523e7522b71;p=thirdparty%2Fgcc.git

tree-optimization/108816 - vect versioning check split confusion

The split of the versioning condition assumes the definition is
in the condition block which is ensured by the versioning code.
But that only works when we actually have to insert any statements
for the versioning condition.  The following adjusts the guard
accordingly and asserts this condition.

	PR tree-optimization/108816
	* tree-vect-loop-manip.cc (vect_loop_versioning): Adjust
	versioning condition split prerequesite, assert required
	invariant.

	* gcc.dg/torture/pr108816.c: New testcase.

(cherry picked from commit 63471c5008819bbf6ec32a6f4d8701fe57b96fa9)
---

diff --git a/gcc/testsuite/gcc.dg/torture/pr108816.c b/gcc/testsuite/gcc.dg/torture/pr108816.c
new file mode 100644
index 000000000000..4c24d5584c18
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr108816.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fvect-cost-model=dynamic" } */
+
+int m;
+
+void
+foo (int p[][16], unsigned int x)
+{
+  while (x < 4)
+    {
+      int j;
+
+      for (j = x * 4; j < (x + 1) * 4 - 2; j++)
+        p[0][j] = p[m][j];
+
+      ++x;
+    }
+}
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index cb5bb87ae337..9d21e6d03107 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -3450,7 +3450,7 @@ vect_loop_versioning (loop_vec_info loop_vinfo,
   tree cost_name = NULL_TREE;
   profile_probability prob2 = profile_probability::uninitialized ();
   if (cond_expr
-      && !integer_truep (cond_expr)
+      && EXPR_P (cond_expr)
       && (version_niter
 	  || version_align
 	  || version_alias
@@ -3684,6 +3684,7 @@ vect_loop_versioning (loop_vec_info loop_vinfo,
   if (cost_name && TREE_CODE (cost_name) == SSA_NAME)
     {
       gimple *def = SSA_NAME_DEF_STMT (cost_name);
+      gcc_assert (gimple_bb (def) == condition_bb);
       /* All uses of the cost check are 'true' after the check we
 	 are going to insert.  */
       replace_uses_by (cost_name, boolean_true_node);