[gcc r12-10457] tree-optimization/111039 - abnormals and bit test merging

[Richard Biener via Gcc-cvs]

https://gcc.gnu.org/g:47e6bff94d980e2fcb6bcb42df04d3b73bd67da7

commit r12-10457-g47e6bff94d980e2fcb6bcb42df04d3b73bd67da7
Author: Richard Biener <rguent...@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.
    
    (cherry picked from commit 482551a79a3d3f107f6239679ee74655cfe8707e)

Diff:
---
 gcc/testsuite/gcc.dg/pr111039.c | 15 +++++++++++++++
 gcc/tree-ssa-ifcombine.cc       |  7 +++++++
 2 files changed, 22 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/pr111039.c b/gcc/testsuite/gcc.dg/pr111039.c
new file mode 100644
index 000000000000..bec9983b35f8
--- /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();
+}
diff --git a/gcc/tree-ssa-ifcombine.cc b/gcc/tree-ssa-ifcombine.cc
index ce9bbebf9480..b139328af224 100644
--- a/gcc/tree-ssa-ifcombine.cc
+++ b/gcc/tree-ssa-ifcombine.cc
@@ -415,6 +415,9 @@ 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),
@@ -465,6 +468,10 @@ 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)
        ;