On Mon, 23 May 2016, Marek Polacek wrote:
> On Mon, May 23, 2016 at 04:36:30PM +0200, Jakub Jelinek wrote:
> > On Mon, May 23, 2016 at 04:28:33PM +0200, Marek Polacek wrote:
> > > As promised in <https://gcc.gnu.org/ml/gcc-patches/2016-05/msg01638.html>,
> > > this is a simple clean-up which makes use of a new predicate. Richi
> > > suggested
> > > adding maybe_drop_lhs_from_noreturn_call which would be nicer, but I
> > > didn't
> > > know how to do that, given the handling if lhs is an SSA_NAME.
> >
> > Shouldn't it be should_remove_lhs_p instead?
> > I mean, it is not just an optimization, but part of how we define the IL.
>
> Aha, ok. Renamed.
>
> > Shouldn't it be also used in tree-cfg.c (verify_gimple_call)?
>
> I left that spot on purpose but now I don't quite see why, fixed. Thanks,
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
Can you move should_remove_lhs_p to tree-cfg.h please?
Ok with that change.
Richard.
> 2016-05-23 Marek Polacek <pola...@redhat.com>
>
> * tree.h (should_remove_lhs_p): New predicate.
> * cgraph.c (cgraph_edge::redirect_call_stmt_to_callee): Use it.
> * gimple-fold.c (gimple_fold_call): Likewise.
> * gimplify.c (gimplify_modify_expr): Likewise.
> * tree-cfg.c (verify_gimple_call): Likewise.
> * tree-cfgcleanup.c (fixup_noreturn_call): Likewise.
>
> diff --git gcc/cgraph.c gcc/cgraph.c
> index cf9192f..1a4f665 100644
> --- gcc/cgraph.c
> +++ gcc/cgraph.c
> @@ -1513,10 +1513,7 @@ cgraph_edge::redirect_call_stmt_to_callee (void)
> }
>
> /* If the call becomes noreturn, remove the LHS if possible. */
> - if (lhs
> - && (gimple_call_flags (new_stmt) & ECF_NORETURN)
> - && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST
> - && !TREE_ADDRESSABLE (TREE_TYPE (lhs)))
> + if (gimple_call_noreturn_p (new_stmt) && should_remove_lhs_p (lhs))
> {
> if (TREE_CODE (lhs) == SSA_NAME)
> {
> diff --git gcc/gimple-fold.c gcc/gimple-fold.c
> index 858f484..6b50d43 100644
> --- gcc/gimple-fold.c
> +++ gcc/gimple-fold.c
> @@ -3052,12 +3052,9 @@ gimple_fold_call (gimple_stmt_iterator *gsi, bool
> inplace)
> == void_type_node))
> gimple_call_set_fntype (stmt, TREE_TYPE (fndecl));
> /* If the call becomes noreturn, remove the lhs. */
> - if (lhs
> - && (gimple_call_flags (stmt) & ECF_NORETURN)
> + if (gimple_call_noreturn_p (stmt)
> && (VOID_TYPE_P (TREE_TYPE (gimple_call_fntype (stmt)))
> - || ((TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs)))
> - == INTEGER_CST)
> - && !TREE_ADDRESSABLE (TREE_TYPE (lhs)))))
> + || should_remove_lhs_p (lhs)))
> {
> if (TREE_CODE (lhs) == SSA_NAME)
> {
> diff --git gcc/gimplify.c gcc/gimplify.c
> index 4a544e3..c77eb51 100644
> --- gcc/gimplify.c
> +++ gcc/gimplify.c
> @@ -4847,9 +4847,7 @@ gimplify_modify_expr (tree *expr_p, gimple_seq *pre_p,
> gimple_seq *post_p,
> }
> }
> notice_special_calls (call_stmt);
> - if (!gimple_call_noreturn_p (call_stmt)
> - || TREE_ADDRESSABLE (TREE_TYPE (*to_p))
> - || TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (*to_p))) != INTEGER_CST)
> + if (!gimple_call_noreturn_p (call_stmt) || !should_remove_lhs_p
> (*to_p))
> gimple_call_set_lhs (call_stmt, *to_p);
> else if (TREE_CODE (*to_p) == SSA_NAME)
> /* The above is somewhat premature, avoid ICEing later for a
> diff --git gcc/tree-cfg.c gcc/tree-cfg.c
> index 7c2ee78..82f0da6c 100644
> --- gcc/tree-cfg.c
> +++ gcc/tree-cfg.c
> @@ -3385,11 +3385,9 @@ verify_gimple_call (gcall *stmt)
> return true;
> }
>
> - if (lhs
> - && gimple_call_ctrl_altering_p (stmt)
> + if (gimple_call_ctrl_altering_p (stmt)
> && gimple_call_noreturn_p (stmt)
> - && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST
> - && !TREE_ADDRESSABLE (TREE_TYPE (lhs)))
> + && should_remove_lhs_p (lhs))
> {
> error ("LHS in noreturn call");
> return true;
> diff --git gcc/tree-cfgcleanup.c gcc/tree-cfgcleanup.c
> index 46d0fa3..4134c38 100644
> --- gcc/tree-cfgcleanup.c
> +++ gcc/tree-cfgcleanup.c
> @@ -604,8 +604,7 @@ fixup_noreturn_call (gimple *stmt)
> temporaries of variable-sized types is not supported. Also don't
> do this with TREE_ADDRESSABLE types, as assign_temp will abort. */
> tree lhs = gimple_call_lhs (stmt);
> - if (lhs && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST
> - && !TREE_ADDRESSABLE (TREE_TYPE (lhs)))
> + if (should_remove_lhs_p (lhs))
> {
> gimple_call_set_lhs (stmt, NULL_TREE);
>
> diff --git gcc/tree.h gcc/tree.h
> index 2510d16..1d72437 100644
> --- gcc/tree.h
> +++ gcc/tree.h
> @@ -5471,4 +5471,14 @@ desired_pro_or_demotion_p (const_tree to_type,
> const_tree from_type)
> return to_type_precision <= TYPE_PRECISION (from_type);
> }
>
> +/* Return true if the LHS of a call should be removed. */
> +
> +inline bool
> +should_remove_lhs_p (tree lhs)
> +{
> + return (lhs
> + && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST
> + && !TREE_ADDRESSABLE (TREE_TYPE (lhs)));
> +}
> +
> #endif /* GCC_TREE_H */
>
> Marek
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
