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 ();