Hi,
On Wed, Jan 15, 2014 at 03:39:09PM +0100, Richard Biener wrote:
> On Wed, Jan 15, 2014 at 1:06 PM, Eric Botcazou <ebotca...@adacore.com> wrote:
> > Yes, it's scalarized during SRA but not ESRA because there is an ehcleanup
> > pass in-between. It used to be scalarized during ESRA up to 4.6.x.
>
> I'm saying even ESRA should be able to scalarize it just fine. It just
> needs to be careful where to insert the loads from the aggregate result
> (on the single outgoing non-EH edge).
>
> Wouldn't that fix your issue?
Eric, more specifically, would the (untested proof of concept) patch
below help?
Martin
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index 4992b4c..a4c0e21 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -1142,6 +1142,26 @@ build_access_from_expr (tree expr, gimple stmt, bool
write)
return false;
}
+/* Return the single non-EH successor edge of BB or NULL if there is none or
+ more than one. */
+
+static edge
+single_non_eh_succ (basic_block bb)
+{
+ edge e, res = NULL;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (!(e->flags & EDGE_EH))
+ {
+ if (res)
+ return NULL;
+ res = e;
+ }
+
+ return res;
+}
+
/* Disqualify LHS and RHS for scalarization if STMT must end its basic block in
modes in which it matters, return true iff they have been disqualified. RHS
may be NULL, in that case ignore it. If we scalarize an aggregate in
@@ -1153,6 +1173,9 @@ disqualify_ops_if_throwing_stmt (gimple stmt, tree lhs,
tree rhs)
if ((sra_mode == SRA_MODE_EARLY_INTRA || sra_mode == SRA_MODE_INTRA)
&& (stmt_can_throw_internal (stmt) || stmt_ends_bb_p (stmt)))
{
+ if (single_non_eh_succ (gimple_bb (stmt)))
+ return false;
+
disqualify_base_of_expr (lhs, "LHS of a throwing stmt.");
if (rhs)
disqualify_base_of_expr (rhs, "RHS of a throwing stmt.");
@@ -2720,6 +2743,19 @@ get_access_for_expr (tree expr)
return get_var_base_offset_size_access (base, offset, max_size);
}
+/* Aplit the sinle non-EH successor edge from BB (there must be exactly one)
+ and return a gsi to the new block. */
+
+static gimple_stmt_iterator
+gsi_for_eh_followups (basic_block bb)
+{
+ edge e = single_non_eh_succ (bb);
+ gcc_assert (e);
+
+ basic_block new_bb = split_edge (e);
+ return gsi_start_bb (new_bb);
+}
+
/* Replace the expression EXPR with a scalar replacement if there is one and
generate other statements to do type conversion or subtree copying if
necessary. GSI is used to place newly created statements, WRITE is true if
@@ -2749,6 +2785,14 @@ sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi,
bool write)
type = TREE_TYPE (*expr);
loc = gimple_location (gsi_stmt (*gsi));
+ gimple_stmt_iterator alt_gsi = gsi_none ();
+ if (write && (stmt_can_throw_internal (gsi_stmt (*gsi))
+ || stmt_ends_bb_p (gsi_stmt (*gsi))))
+ {
+ alt_gsi = gsi_for_eh_followups (gsi_bb (*gsi));
+ gsi = &alt_gsi;
+ }
+
if (access->grp_to_be_replaced)
{
tree repl = get_access_replacement (access);
@@ -3208,14 +3252,25 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator
*gsi)
if (modify_this_stmt
|| gimple_has_volatile_ops (*stmt)
|| contains_vce_or_bfcref_p (rhs)
- || contains_vce_or_bfcref_p (lhs))
+ || contains_vce_or_bfcref_p (lhs)
+ || stmt_can_throw_internal (*stmt)
+ || stmt_ends_bb_p (*stmt))
{
if (access_has_children_p (racc))
generate_subtree_copies (racc->first_child, racc->base, 0, 0, 0,
gsi, false, false, loc);
if (access_has_children_p (lacc))
- generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
- gsi, true, true, loc);
+ {
+ gimple_stmt_iterator alt_gsi = gsi_none ();
+ if (stmt_can_throw_internal (*stmt)
+ || stmt_ends_bb_p (*stmt))
+ {
+ alt_gsi = gsi_for_eh_followups (gsi_bb (*gsi));
+ gsi = &alt_gsi;
+ }
+ generate_subtree_copies (lacc->first_child, lacc->base, 0, 0, 0,
+ gsi, true, true, loc);
+ }
sra_stats.separate_lhs_rhs_handling++;
/* This gimplification must be done after generate_subtree_copies,
@@ -3309,8 +3364,13 @@ sra_modify_function_body (void)
{
bool cfg_changed = false;
basic_block bb;
+ vec<basic_block> bb_list = vNULL;
FOR_EACH_BB_FN (bb, cfun)
+ bb_list.safe_push (bb);
+
+ unsigned bb_vec_index;
+ FOR_EACH_VEC_ELT (bb_list, bb_vec_index, bb)
{
gimple_stmt_iterator gsi = gsi_start_bb (bb);
while (!gsi_end_p (gsi))
@@ -3379,6 +3439,7 @@ sra_modify_function_body (void)
}
}
+ bb_list.release ();
return cfg_changed;
}
