From: Tamar Christina <tamar.christina@arm.com>
Date: Mon, 23 Sep 2024 10:45:43 +0000 (+0100)
Subject: middle-end: Insert invariant instructions before the gsi [PR116812]
X-Git-Tag: basepoints/gcc-16~5761
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09892448ebd8c396a26b2c09ba71f1e5a8dc42d7;p=thirdparty%2Fgcc.git

middle-end: Insert invariant instructions before the gsi [PR116812]

The new invariant statements should be inserted before the current
statement and not after.  This goes fine 99% of the time but when the
current statement is a gcond the control flow gets corrupted.

gcc/ChangeLog:

	PR tree-optimization/116812
	* tree-vect-slp.cc (vect_slp_region): Fix insertion.

gcc/testsuite/ChangeLog:

	PR tree-optimization/116812
	* gcc.dg/vect/pr116812.c: New test.
---

diff --git a/gcc/testsuite/gcc.dg/vect/pr116812.c b/gcc/testsuite/gcc.dg/vect/pr116812.c
new file mode 100644
index 00000000000..3e83c13d94b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr116812.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O2 -fno-tree-dce -fno-tree-dse" } */
+
+int a, b, c, d, e, f[2], g, h;
+int k(int j) { return 2 >> a ? 2 >> a : a; }
+int main() {
+  int i;
+  for (; g; g = k(d = 0))
+    ;
+  if (a)
+    b && h;
+  for (e = 0; e < 2; e++)
+    c = d & 1 ? d : 0;
+  for (i = 0; i < 2; i++)
+    f[i] = 0;
+  return 0;
+}
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 600987dd6e5..7161492f511 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9168,10 +9168,8 @@ vect_slp_region (vec<basic_block> bbs, vec<data_reference_p> datarefs,
 		dump_printf_loc (MSG_NOTE, vect_location,
 			 "------>generating invariant statements\n");
 
-	      gimple_stmt_iterator gsi;
-	      gsi = gsi_after_labels (bb_vinfo->bbs[0]);
-	      gsi_insert_seq_after (&gsi, bb_vinfo->inv_pattern_def_seq,
-				    GSI_CONTINUE_LINKING);
+	      bb_vinfo->insert_seq_on_entry (NULL,
+					     bb_vinfo->inv_pattern_def_seq);
 	    }
 	}
       else