> This exposed a couple of similar bugs in cse.c and postreload-gcse.c: the
> code was effectively treating a basic block with a single, abnormal
> incoming edge as if the edge was normal.
I've installed the following refined fix, after testing on i586-suse-linux and
sparc-sun-solaris2.10. Most EDGE_ABNORMAL edges can very likely be treated
normally here, for example EH edges when call-saved registers are considered.
The only really problematic ones are EDGE_ABNORMAL_CALL edges when there is a
non-local label in the function, because even call-saved registers are not
guaranteed to be preserved in this case.
2011-06-02 Eric Botcazou <ebotca...@adacore.com>
* cse.c (cse_find_path): Refine change to exclude EDGE_ABNORMAL_CALL
edges only, when there is a non-local label in the function.
* postreload-gcse.c (bb_has_well_behaved_predecessors): Likewise.
--
Eric Botcazou
Index: cse.c
===================================================================
--- cse.c (revision 174564)
+++ cse.c (working copy)
@@ -6193,7 +6193,7 @@ cse_find_path (basic_block first_bb, str
e = NULL;
if (e
- && (e->flags & EDGE_ABNORMAL) == 0
+ && !((e->flags & EDGE_ABNORMAL_CALL) && cfun->has_nonlocal_label)
&& e->dest != EXIT_BLOCK_PTR
&& single_pred_p (e->dest)
/* Avoid visiting basic blocks twice. The large comment
Index: postreload-gcse.c
===================================================================
--- postreload-gcse.c (revision 174564)
+++ postreload-gcse.c (working copy)
@@ -912,12 +912,10 @@ get_avail_load_store_reg (rtx insn)
static bool
bb_has_well_behaved_predecessors (basic_block bb)
{
- unsigned int edge_count = EDGE_COUNT (bb->preds);
edge pred;
edge_iterator ei;
- if (edge_count == 0
- || (edge_count == 1 && (single_pred_edge (bb)->flags & EDGE_ABNORMAL)))
+ if (EDGE_COUNT (bb->preds) == 0)
return false;
FOR_EACH_EDGE (pred, ei, bb->preds)
@@ -925,6 +923,9 @@ bb_has_well_behaved_predecessors (basic_
if ((pred->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (pred))
return false;
+ if ((pred->flags & EDGE_ABNORMAL_CALL) && cfun->has_nonlocal_label)
+ return false;
+
if (JUMP_TABLE_DATA_P (BB_END (pred->src)))
return false;
}
