[PATCH] Fix PR82264

[Richard Biener]

One forgets that dyn_cast doesn't work like dynamic_cast ...

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2017-09-20  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/82264
        * tree-ssa-sccvn.c (vn_phi_eq): Use safe_dyn_cast to check
        for GIMPLE_CONDs.
        (vn_phi_lookup): Likewise.
        (vn_phi_insert): Likewise.

        * gcc.dg/torture/pr82264.c: New testcase.

Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c        (revision 253001)
+++ gcc/tree-ssa-sccvn.c        (working copy)
@@ -3028,16 +3028,13 @@ vn_phi_eq (const_vn_phi_t const vp1, con
              return false;
 
            /* Verify the controlling stmt is the same.  */
-           gimple *last1 = last_stmt (idom1);
-           gimple *last2 = last_stmt (idom2);
-           if (gimple_code (last1) != GIMPLE_COND
-               || gimple_code (last2) != GIMPLE_COND)
+           gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1));
+           gcond *last2 = safe_dyn_cast <gcond *> (last_stmt (idom2));
+           if (! last1 || ! last2)
              return false;
            bool inverted_p;
-           if (! cond_stmts_equal_p (as_a <gcond *> (last1),
-                                     vp1->cclhs, vp1->ccrhs,
-                                     as_a <gcond *> (last2),
-                                     vp2->cclhs, vp2->ccrhs,
+           if (! cond_stmts_equal_p (last1, vp1->cclhs, vp1->ccrhs,
+                                     last2, vp2->cclhs, vp2->ccrhs,
                                      &inverted_p))
              return false;
 
@@ -3122,7 +3119,7 @@ vn_phi_lookup (gimple *phi)
   vp1.ccrhs = NULL_TREE;
   basic_block idom1 = get_immediate_dominator (CDI_DOMINATORS, vp1.block);
   if (EDGE_COUNT (idom1->succs) == 2)
-    if (gcond *last1 = dyn_cast <gcond *> (last_stmt (idom1)))
+    if (gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1)))
       {
        vp1.cclhs = vn_valueize (gimple_cond_lhs (last1));
        vp1.ccrhs = vn_valueize (gimple_cond_rhs (last1));
@@ -3168,7 +3165,7 @@ vn_phi_insert (gimple *phi, tree result)
   vp1->ccrhs = NULL_TREE;
   basic_block idom1 = get_immediate_dominator (CDI_DOMINATORS, vp1->block);
   if (EDGE_COUNT (idom1->succs) == 2)
-    if (gcond *last1 = dyn_cast <gcond *> (last_stmt (idom1)))
+    if (gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1)))
       {
        vp1->cclhs = vn_valueize (gimple_cond_lhs (last1));
        vp1->ccrhs = vn_valueize (gimple_cond_rhs (last1));
Index: gcc/testsuite/gcc.dg/torture/pr82264.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr82264.c      (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr82264.c      (working copy)
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+
+char a;
+int c;
+unsigned b ();
+unsigned
+setjmp ()
+{
+}
+static void
+d ()
+{
+  if (b ())
+    c = 3;
+}
+void
+e ()
+{
+  d ();
+  a && ({ setjmp (); });
+}