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?
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
