gcc/gcc11-pr111039.patch

commit 482551a79a3d3f107f6239679ee74655cfe8707e
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Aug 17 13:10:14 2023 +0200

    tree-optimization/111039 - abnormals and bit test merging
    
    The following guards the bit test merging code in if-combine against
    the appearance of SSA names used in abnormal PHIs.
    
            PR tree-optimization/111039
            * tree-ssa-ifcombine.cc (ifcombine_ifandif): Check for
            SSA_NAME_OCCURS_IN_ABNORMAL_PHI.
    
            * gcc.dg/pr111039.c: New testcase.

diff --git a/gcc/testsuite/gcc.dg/pr111039.c b/gcc/testsuite/gcc.dg/pr111039.c
new file mode 100644
index 00000000000..bec9983b35f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr111039.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+int _setjmp ();
+void abcd ();
+void abcde ();
+void compiler_corruption_function(int flags)
+{
+  int nowait = flags & 1048576, isexpand = flags & 8388608;
+  abcd();
+  _setjmp(flags);
+  if (nowait && isexpand)
+    flags &= 0;
+  abcde();
+}
--- a/gcc/tree-ssa-ifcombine.c
+++ b/gcc/tree-ssa-ifcombine.c
@@ -430,6 +430,9 @@ ifcombine_ifandif (basic_block inner_cond_bb, bool inner_inv,
     {
       tree t, t2;
 
+      if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name1))
+	return false;
+
       /* Do it.  */
       gsi = gsi_for_stmt (inner_cond);
       t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
@@ -486,6 +489,10 @@ ifcombine_ifandif (basic_block inner_cond_bb, bool inner_inv,
       gimple_stmt_iterator gsi;
       tree t;
 
+      if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name1)
+	  || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name2))
+	return false;
+
       /* Find the common name which is bit-tested.  */
       if (name1 == name2)
 	;