[PATCH] Fix gimple_ic if adding a noreturn direct call variant to an indirect not noreturn call (PR tree-optimization/51719)

[Jakub Jelinek]

Hi!

When gimple_ic is changing an indirect call into
if (cond)
  direct_call ();
else
  (*indirect_call) ()
and the indirect_call is not noreturn, but direct_call is
noreturn, we ICE during checking after profile, because the noreturn
call still has lhs set and edges that it shouldn't have.

The following patch fixes, it, bootstrapped/regtested on x86_64-linux
and i686-linux, ok for trunk?

2012-01-02  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/51719
        * value-prof.c (gimple_ic): When indirect call isn't noreturn,
        but direct call is, clear direct call's lhs and don't add fallthrough
        edge from dcall_bb to join_bb and PHIs.

        * g++.dg/tree-prof/pr51719.C: New test.

--- gcc/value-prof.c.jj 2011-08-18 08:36:00.000000000 +0200
+++ gcc/value-prof.c    2012-01-02 19:01:33.760867971 +0100
@@ -1149,7 +1149,7 @@ gimple_ic (gimple icall_stmt, struct cgr
   tree optype = build_pointer_type (void_type_node);
   edge e_cd, e_ci, e_di, e_dj = NULL, e_ij;
   gimple_stmt_iterator gsi;
-  int lp_nr;
+  int lp_nr, dflags;
 
   cond_bb = gimple_bb (icall_stmt);
   gsi = gsi_for_stmt (icall_stmt);
@@ -1176,6 +1176,9 @@ gimple_ic (gimple icall_stmt, struct cgr
   update_stmt (icall_stmt);
   dcall_stmt = gimple_copy (icall_stmt);
   gimple_call_set_fndecl (dcall_stmt, direct_call->decl);
+  dflags = flags_from_decl_or_type (direct_call->decl);
+  if ((dflags & ECF_NORETURN) != 0)
+    gimple_call_set_lhs (dcall_stmt, NULL_TREE);
   gsi_insert_before (&gsi, dcall_stmt, GSI_SAME_STMT);
 
   /* Fix CFG. */
@@ -1220,17 +1223,23 @@ gimple_ic (gimple icall_stmt, struct cgr
 
   if (e_ij != NULL)
     {
-      e_dj = make_edge (dcall_bb, join_bb, EDGE_FALLTHRU);
-      e_dj->probability = REG_BR_PROB_BASE;
-      e_dj->count = count;
+      if ((dflags & ECF_NORETURN) != 0)
+       e_ij->count = all;
+      else
+       {
+         e_dj = make_edge (dcall_bb, join_bb, EDGE_FALLTHRU);
+         e_dj->probability = REG_BR_PROB_BASE;
+         e_dj->count = count;
 
+         e_ij->count = all - count;
+       }
       e_ij->probability = REG_BR_PROB_BASE;
-      e_ij->count = all - count;
     }
 
   /* Insert PHI node for the call result if necessary.  */
   if (gimple_call_lhs (icall_stmt)
-      && TREE_CODE (gimple_call_lhs (icall_stmt)) == SSA_NAME)
+      && TREE_CODE (gimple_call_lhs (icall_stmt)) == SSA_NAME
+      && (dflags & ECF_NORETURN) == 0)
     {
       tree result = gimple_call_lhs (icall_stmt);
       gimple phi = create_phi_node (result, join_bb);
--- gcc/testsuite/g++.dg/tree-prof/pr51719.C.jj 2012-01-02 19:11:27.633358952 
+0100
+++ gcc/testsuite/g++.dg/tree-prof/pr51719.C    2012-01-02 19:12:27.797004399 
+0100
@@ -0,0 +1,27 @@
+// PR tree-optimization/51719
+// { dg-options "-O -fpartial-inlining" }
+
+int
+bar (void)
+{
+  throw 1;
+}
+
+int __attribute__ ((noinline, noclone))
+foo (int (*f) (void))
+{
+  try
+  {
+    return (*f) ();
+  }
+  catch (...)
+  {
+  }
+  return 0;
+}
+
+int
+main ()
+{
+  return foo (bar);
+}

        Jakub