Handle EAF_DIRECT and EAF_UNUSED of pure calls

[Jan Hubicka]

Hi,
while looking into structalias I noticed that we ignore EAF flags here.
This is pity since we still can apply direct and unused.
This patch simply copies logic from normal call handling. I relaize that
it is bit more expensive by creating callarg and doing transitive
closure there instead of doing one common transitive closure on call use.
I can also scan first if there are both direct and !direct argument and
do this optimization, but it does not seem to affect build times (tested
on spec2k6 gcc LTO build)

lto-boostrapped/regtested x86_64-linux.

Honza

diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index a4832b75436..5f84f7d467f 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -4253,12 +4253,20 @@ handle_pure_call (gcall *stmt, vec<ce_s> *results)
   for (i = 0; i < gimple_call_num_args (stmt); ++i)
     {
       tree arg = gimple_call_arg (stmt, i);
+      int flags = gimple_call_arg_flags (stmt, i);
+
+      if (flags & EAF_UNUSED)
+       continue;
+
       if (!uses)
-       {
-         uses = get_call_use_vi (stmt);
-         make_any_offset_constraints (uses);
-         make_transitive_closure_constraints (uses);
-       }
+       uses = get_call_use_vi (stmt);
+      varinfo_t tem = new_var_info (NULL_TREE, "callarg", true);
+      tem->is_reg_var = true;
+      make_constraint_to (tem->id, arg);
+      make_any_offset_constraints (tem);
+      if (!(flags & EAF_DIRECT))
+       make_transitive_closure_constraints (tem);
+      make_copy_constraint (uses, tem->id);
       make_constraint_to (uses->id, arg);
     }