+ switch (GET_CODE (exp))
+ {
+ case AND:
+ compute_predicate_codes (XEXP (exp, 0), op0_codes);
+ compute_predicate_codes (XEXP (exp, 1), op1_codes);
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ codes[i] = TRISTATE_AND (op0_codes[i], op1_codes[i]);
+ break;
+
+ case IOR:
+ compute_predicate_codes (XEXP (exp, 0), op0_codes);
+ compute_predicate_codes (XEXP (exp, 1), op1_codes);
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ codes[i] = TRISTATE_OR (op0_codes[i], op1_codes[i]);
+ break;
+ case NOT:
+ compute_predicate_codes (XEXP (exp, 0), op0_codes);
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ codes[i] = TRISTATE_NOT (op0_codes[i]);
+ break;
+
+ case IF_THEN_ELSE:
+ /* a ? b : c accepts the same codes as (a & b) | (!a & c). */
+ compute_predicate_codes (XEXP (exp, 0), op0_codes);
+ compute_predicate_codes (XEXP (exp, 1), op1_codes);
+ compute_predicate_codes (XEXP (exp, 2), op2_codes);
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ codes[i] = TRISTATE_OR (TRISTATE_AND (op0_codes[i], op1_codes[i]),
+ TRISTATE_AND (TRISTATE_NOT (op0_codes[i]),
+ op2_codes[i]));
+ break;
+
+ case MATCH_CODE:
+ /* MATCH_CODE allows a specified list of codes. However, if it
+ does not apply to the top level of the expression, it does not
+ constrain the set of codes for the top level. */
+ if (XSTR (exp, 1)[0] != '\0')
+ {
+ memset (codes, Y, NUM_RTX_CODE);
+ break;
+ }
+
+ memset (codes, N, NUM_RTX_CODE);
+ {
+ const char *next_code = XSTR (exp, 0);
+ const char *code;
+
+ if (*next_code == '\0')
+ {
+ message_with_line (pattern_lineno, "empty match_code expression");
+ error_count++;
+ break;
+ }
+
+ while ((code = scan_comma_elt (&next_code)) != 0)
+ {
+ size_t n = next_code - code;
+ int found_it = 0;
+
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ if (!strncmp (code, GET_RTX_NAME (i), n)
+ && GET_RTX_NAME (i)[n] == '\0')
+ {
+ codes[i] = Y;
+ found_it = 1;
+ break;
+ }
+ if (!found_it)
+ {
+ message_with_line (pattern_lineno, "match_code \"%.*s\" matches nothing",
+ (int) n, code);
+ error_count ++;
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ if (!strncasecmp (code, GET_RTX_NAME (i), n)
+ && GET_RTX_NAME (i)[n] == '\0'
+ && !did_you_mean_codes[i])
+ {
+ did_you_mean_codes[i] = 1;
+ message_with_line (pattern_lineno, "(did you mean \"%s\"?)", GET_RTX_NAME (i));
+ }
+ }
+
+ }
+ }
+ break;
+
+ case MATCH_OPERAND:
+ /* MATCH_OPERAND disallows the set of codes that the named predicate
+ disallows, and is indeterminate for the codes that it does allow. */
+ {
+ struct pred_data *p = lookup_predicate (XSTR (exp, 1));
+ if (!p)
+ {
+ message_with_line (pattern_lineno,
+ "reference to unknown predicate '%s'",
+ XSTR (exp, 1));
+ error_count++;
+ break;
+ }
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ codes[i] = p->codes[i] ? I : N;
+ }
+ break;
+
+
+ case MATCH_TEST:
+ /* (match_test WHATEVER) is completely indeterminate. */
+ memset (codes, I, NUM_RTX_CODE);
+ break;
+
+ default:
+ message_with_line (pattern_lineno,
+ "'%s' cannot be used in a define_predicate expression",
+ GET_RTX_NAME (GET_CODE (exp)));
+ error_count++;
+ memset (codes, I, NUM_RTX_CODE);
+ break;
+ }
+}
+
+#undef TRISTATE_OR
+#undef TRISTATE_AND
+#undef TRISTATE_NOT
+
+/* Process a define_predicate expression: compute the set of predicates
+ that can be matched, and record this as a known predicate. */
+static void
+process_define_predicate (rtx desc)