Hi!
On Sat, Mar 20, 2021 at 10:53:32AM -0400, Vladimir Makarov via Gcc-patches
wrote:
> It seems CONSTRAINT_LEN treats constraint '\0' as one having length 1.
Maybe we should fix that? See attached patch.
Segher
diff --git a/gcc/genpreds.c b/gcc/genpreds.c
index 8499a2a2383b..b83a030d6a5d 100644
--- a/gcc/genpreds.c
+++ b/gcc/genpreds.c
@@ -1141,6 +1141,9 @@ write_insn_constraint_len (void)
" switch (fc)\n"
" {");
+ /* Empty constraints have length 0. */
+ printf (" case 0: return 0;\n");
+
for (i = 0; i < ARRAY_SIZE (constraints_by_letter_table); i++)
{
class constraint_data *c = constraints_by_letter_table[i];
@@ -1470,14 +1473,9 @@ write_tm_preds_h (void)
address_start, address_end);
write_allows_reg_mem_function ();
- if (constraint_max_namelen > 1)
- {
- write_insn_constraint_len ();
- puts ("#define CONSTRAINT_LEN(c_,s_) "
- "insn_constraint_len (c_,s_)\n");
- }
- else
- puts ("#define CONSTRAINT_LEN(c_,s_) 1\n");
+ write_insn_constraint_len ();
+ puts ("#define CONSTRAINT_LEN(c_,s_) insn_constraint_len (c_,s_)\n");
+
if (have_register_constraints)
puts ("extern enum reg_class reg_class_for_constraint_1 "
"(enum constraint_num);\n"
