After the earlier changes, the only important function that switches on
constraint_num is constraint_satisfied_p (now constraint_satisfied_p_1).
Since constraint_num is a dense enum, it seems faster to use a jump
table instead. In many cases this allows the handling function to be
a simple sibcall to something like a predicate.
Richard
gcc/
* genpreds.c (write_constraint_satisfied_p_1): Replace with...
(write_constraint_satisfied_p_array): ...this new function.
(write_tm_preds_h): Replace write_constraint_satisfied_p_1 with
an array.
(write_insn_preds_c): Update accordingly.
Index: gcc/genpreds.c
===================================================================
--- gcc/genpreds.c 2014-06-05 21:05:45.972964371 +0100
+++ gcc/genpreds.c 2014-06-05 21:05:49.372993717 +0100
@@ -1166,29 +1166,19 @@ #define GCC_TM_CONSTRS_H\n");
a CONSTRAINT_xxx constant to one of the predicate functions generated
above. */
static void
-write_constraint_satisfied_p_1 (void)
+write_constraint_satisfied_p_array (void)
{
- struct constraint_data *c;
-
if (satisfied_start == num_constraints)
return;
- puts ("bool\n"
- "constraint_satisfied_p_1 (rtx op, enum constraint_num c)\n"
- "{\n"
- " switch (c)\n"
- " {");
-
- FOR_ALL_CONSTRAINTS (c)
- if (!c->is_register)
- printf (" case CONSTRAINT_%s: "
- "return satisfies_constraint_%s (op);\n",
- c->c_name, c->c_name);
-
- puts (" default: break;\n"
- " }\n"
- " return false;\n"
- "}\n");
+ printf ("bool (*constraint_satisfied_p_array[]) (rtx) = {\n ");
+ for (unsigned int i = satisfied_start; i < num_constraints; ++i)
+ {
+ if (i != satisfied_start)
+ printf (",\n ");
+ printf ("satisfies_constraint_%s", enum_order[i]->c_name);
+ }
+ printf ("\n};\n\n");
}
/* Write out the function which computes whether a given value matches
@@ -1293,16 +1283,15 @@ #define GCC_TM_PREDS_H\n\
" return false;\n"
"}\n");
else
- printf ("extern bool constraint_satisfied_p_1 (rtx,"
- " enum constraint_num);\n"
+ printf ("extern bool (*constraint_satisfied_p_array[]) (rtx);\n"
"\n"
"/* Return true if X satisfies constraint C. */\n"
"\n"
"static inline bool\n"
"constraint_satisfied_p (rtx x, enum constraint_num c)\n"
"{\n"
- " return c >= CONSTRAINT_%s"
- " && constraint_satisfied_p_1 (x, c);\n"
+ " int i = (int) c - (int) CONSTRAINT_%s;\n"
+ " return i >= 0 && constraint_satisfied_p_array[i] (x);\n"
"}\n"
"\n",
enum_order[satisfied_start]->name);
@@ -1425,7 +1414,7 @@ write_insn_preds_c (void)
write_lookup_constraint_array ();
if (have_register_constraints)
write_reg_class_for_constraint_1 ();
- write_constraint_satisfied_p_1 ();
+ write_constraint_satisfied_p_array ();
if (have_const_int_constraints)
write_insn_const_int_ok_for_constraint ();
