[PATCH] Fix PR85168

[Richard Biener]

The following fixes a bad propagation of abnormals in VN valueization.

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

Richard.

2018-04-04  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/85168
        * tree-ssa-sccvn.c (vn_reference_maybe_forwprop_address): Avoid
        propagating abnormals.

        * gcc.dg/torture/pr85168.c: New testcase.

Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c        (revision 259024)
+++ gcc/tree-ssa-sccvn.c        (working copy)
@@ -1249,7 +1249,9 @@ vn_reference_maybe_forwprop_address (vec
          return true;
        }
       if (!addr_base
-         || TREE_CODE (addr_base) != MEM_REF)
+         || TREE_CODE (addr_base) != MEM_REF
+         || (TREE_CODE (TREE_OPERAND (addr_base, 0)) == SSA_NAME
+             && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (addr_base, 0))))
        return false;
 
       off += addr_offset;
@@ -1262,6 +1264,7 @@ vn_reference_maybe_forwprop_address (vec
       ptr = gimple_assign_rhs1 (def_stmt);
       ptroff = gimple_assign_rhs2 (def_stmt);
       if (TREE_CODE (ptr) != SSA_NAME
+         || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)
          || TREE_CODE (ptroff) != INTEGER_CST)
        return false;
 
Index: gcc/testsuite/gcc.dg/torture/pr85168.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr85168.c      (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr85168.c      (working copy)
@@ -0,0 +1,30 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target indirect_jumps } */
+
+typedef struct {
+    struct {
+       char a;
+    } b;
+} c;
+
+int d, f;
+c *e;
+
+extern void i(void);
+extern void sejtmp () __attribute__((returns_twice));
+
+void g(void)
+{
+  c *h = e;
+  if (f)
+    {
+      i();
+      h--;
+      if (d)
+       if (h->b.a)
+         i();
+    }
+  if (h->b.a)
+    sejtmp();
+  e = h;
+}