Re: [PATCH] Fix einline ICE with EH (PR tree-optimization/64465)

[Jan Hubicka <hubicka at ucw dot cz>]

> Hi!
> 
> The early inliner ICEs on the following testcase, because redirect_all_calls
> replaces a call to a function that could throw with __builtin_unreachable
> (and, note, it still has the bug that it doesn't drop the function
> arguments), but nothing cleans up the EH stuff for that change.
> 
> During function versioning fixup_cfg pass is supposed to handle that,
> during IPA inlining there is explicit call to execute_fixup_cfg, but during
> early inlining there is not.

I am still confused why early inliner does any redirections? It should not.
Edge redirection is part of the IPA optimization machinery.
> 
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk?
> 
> Honza, will you take care of dropping the arguments when you redirect to
> a function that takes no arguments (I believe only __builtin_unreachable
> and __pure_virtual are the cases where we do that).

Yep, i will try to find time for that after arriving to Calgary this weekend.
There are quite few places where substitution can happen, so I need to check
them curefuly.

Honza
> 
> 2015-01-05  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR tree-optimization/64465
> 	* tree-inline.c (redirect_all_calls): During inlining
> 	clean up EH stmts and EH edges if redirect_call_stmt_to_callee
> 	changed the stmt to a non-throwing call.
> 
> 	* gcc.dg/pr64465.c: New test.
> 
> --- gcc/tree-inline.c.jj	2015-01-05 13:07:15.186507607 +0100
> +++ gcc/tree-inline.c	2015-01-05 15:30:33.715001491 +0100
> @@ -2582,13 +2582,19 @@ void
>  redirect_all_calls (copy_body_data * id, basic_block bb)
>  {
>    gimple_stmt_iterator si;
> +  gimple last = last_stmt (bb);
>    for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
>      {
> -      if (is_gimple_call (gsi_stmt (si)))
> +      gimple stmt = gsi_stmt (si);
> +      if (is_gimple_call (stmt))
>  	{
> -	  struct cgraph_edge *edge = id->dst_node->get_edge (gsi_stmt (si));
> +	  struct cgraph_edge *edge = id->dst_node->get_edge (stmt);
>  	  if (edge)
> -	    edge->redirect_call_stmt_to_callee ();
> +	    {
> +	      edge->redirect_call_stmt_to_callee ();
> +	      if (stmt == last && id->call_stmt && maybe_clean_eh_stmt (stmt))
> +		gimple_purge_dead_eh_edges (bb);
> +	    }
>  	}
>      }
>  }
> --- gcc/testsuite/gcc.dg/pr64465.c.jj	2015-01-05 15:06:31.369183163 +0100
> +++ gcc/testsuite/gcc.dg/pr64465.c	2015-01-05 15:06:31.369183163 +0100
> @@ -0,0 +1,22 @@
> +/* PR tree-optimization/64465 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fexceptions" } */
> +
> +extern int foo (int *);
> +extern int bar (int, int);
> +static inline __attribute__ ((__always_inline__))
> +int baz (int o)
> +{
> +  if (__builtin_constant_p (o))
> +    return bar (o, 1);
> +  return bar (o, 0);
> +}
> +
> +void
> +test (void)
> +{
> +  int s;
> +  foo (&s);
> +  baz (4);
> +  baz (s);
> +}
> 
> 	Jakub