return rt;
}
\f
+/* Predicate handling.
+
+ We construct from the machine description a table mapping each
+ predicate to a list of the rtl codes it can possibly match. The
+ function 'maybe_both_true' uses it to deduce that there are no
+ expressions that can be matches by certain pairs of tree nodes.
+ Also, if a predicate can match only one code, we can hardwire that
+ code into the node testing the predicate.
+
+ Some predicates are flagged as special. validate_pattern will not
+ warn about modeless match_operand expressions if they have a
+ special predicate. Predicates that allow only constants are also
+ treated as special, for this purpose.
+
+ validate_pattern will warn about predicates that allow non-lvalues
+ when they appear in destination operands.
+
+ Calculating the set of rtx codes that can possibly be accepted by a
+ predicate expression EXP requires a three-state logic: any given
+ subexpression may definitively accept a code C (Y), definitively
+ reject a code C (N), or may have an indeterminate effect (I). N
+ and I is N; Y or I is Y; Y and I, N or I are both I. Here are full
+ truth tables.
+
+ a b a&b a|b
+ Y Y Y Y
+ N Y N Y
+ N N N N
+ I Y I Y
+ I N N I
+ I I I I
+
+ We represent Y with 1, N with 0, I with 2. If any code is left in
+ an I state by the complete expression, we must assume that that
+ code can be accepted. */
+
+#define N 0
+#define Y 1
+#define I 2
+
+#define TRISTATE_AND(a,b) \
+ ((a) == I ? ((b) == N ? N : I) : \
+ (b) == I ? ((a) == N ? N : I) : \
+ (a) && (b))
+
+#define TRISTATE_OR(a,b) \
+ ((a) == I ? ((b) == Y ? Y : I) : \
+ (b) == I ? ((a) == Y ? Y : I) : \
+ (a) || (b))
+
+#define TRISTATE_NOT(a) \
+ ((a) == I ? I : !(a))
+
+/* 0 means no warning about that code yet, 1 means warned. */
+static char did_you_mean_codes[NUM_RTX_CODE];
+
+/* Recursively calculate the set of rtx codes accepted by the
+ predicate expression EXP, writing the result to CODES. LINENO is
+ the line number on which the directive containing EXP appeared. */
+
+static void
+compute_predicate_codes (rtx exp, int lineno, char codes[NUM_RTX_CODE])
+{
+ char op0_codes[NUM_RTX_CODE];
+ char op1_codes[NUM_RTX_CODE];
+ char op2_codes[NUM_RTX_CODE];
+ int i;
+
+ switch (GET_CODE (exp))
+ {
+ case AND:
+ compute_predicate_codes (XEXP (exp, 0), lineno, op0_codes);
+ compute_predicate_codes (XEXP (exp, 1), lineno, 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), lineno, op0_codes);
+ compute_predicate_codes (XEXP (exp, 1), lineno, 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), lineno, 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), lineno, op0_codes);
+ compute_predicate_codes (XEXP (exp, 1), lineno, op1_codes);
+ compute_predicate_codes (XEXP (exp, 2), lineno, 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')
+ {
+ error_with_line (lineno, "empty match_code expression");
+ 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)
+ {
+ error_with_line (lineno,
+ "match_code \"%.*s\" matches nothing",
+ (int) n, code);
+ 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 (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)
+ {
+ error_with_line (lineno, "reference to unknown predicate '%s'",
+ XSTR (exp, 1));
+ 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:
+ error_with_line (lineno,
+ "'%s' cannot be used in a define_predicate expression",
+ GET_RTX_NAME (GET_CODE (exp)));
+ memset (codes, I, NUM_RTX_CODE);
+ break;
+ }
+}
+
+#undef TRISTATE_OR
+#undef TRISTATE_AND
+#undef TRISTATE_NOT
+
+/* Return true if NAME is a valid predicate name. */
+
+static bool
+valid_predicate_name_p (const char *name)
+{
+ const char *p;
+
+ if (!ISALPHA (name[0]) && name[0] != '_')
+ return false;
+ for (p = name + 1; *p; p++)
+ if (!ISALNUM (*p) && *p != '_')
+ return false;
+ return true;
+}
+
+/* Process define_predicate directive DESC, which appears on line number
+ LINENO. Compute the set of codes that can be matched, and record this
+ as a known predicate. */
+
+static void
+process_define_predicate (rtx desc, int lineno)
+{
+ struct pred_data *pred;
+ char codes[NUM_RTX_CODE];
+ int i;
+
+ if (!valid_predicate_name_p (XSTR (desc, 0)))
+ {
+ error_with_line (lineno,
+ "%s: predicate name must be a valid C function name",
+ XSTR (desc, 0));
+ return;
+ }
+
+ pred = XCNEW (struct pred_data);
+ pred->name = XSTR (desc, 0);
+ pred->exp = XEXP (desc, 1);
+ pred->c_block = XSTR (desc, 2);
+ if (GET_CODE (desc) == DEFINE_SPECIAL_PREDICATE)
+ pred->special = true;
+
+ compute_predicate_codes (XEXP (desc, 1), lineno, codes);
+
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ if (codes[i] != N)
+ add_predicate_code (pred, (enum rtx_code) i);
+
+ add_predicate (pred);
+}
+#undef I
+#undef N
+#undef Y
+\f
/* Queue PATTERN on LIST_TAIL. Return the address of the new queue
element. */
case DEFINE_PREDICATE:
case DEFINE_SPECIAL_PREDICATE:
+ process_define_predicate (desc, lineno);
+ /* Fall through. */
+
case DEFINE_CONSTRAINT:
case DEFINE_REGISTER_CONSTRAINT:
case DEFINE_MEMORY_CONSTRAINT:
if (p_true == NULL || strchr (++p_true, ',') != NULL)
{
error_with_line (elem->lineno, "attribute `predicable' is not a boolean");
- if (p_false)
- free (p_false);
+ free (p_false);
return;
}
p_true[-1] = '\0';
case CONST:
error_with_line (elem->lineno, "attribute `predicable' cannot be const");
- if (p_false)
- free (p_false);
+ free (p_false);
return;
default:
error_with_line (elem->lineno,
"attribute `predicable' must have a constant default");
- if (p_false)
- free (p_false);
+ free (p_false);
return;
}
{
error_with_line (elem->lineno,
"unknown value `%s' for `predicable' attribute", value);
- if (p_false)
- free (p_false);
+ free (p_false);
}
}
their C test is provably always false). If insn_elision is
false, our caller needs to see all the patterns. Note that the
elided patterns are never counted by the sequence numbering; it
- it is the caller's responsibility, when insn_elision is false, not
+ is the caller's responsibility, when insn_elision is false, not
to use elided pattern numbers for anything. */
switch (GET_CODE (desc))
{
insn_name_ptr[code] = new_name;
}
+\f
+/* Make STATS describe the operands that appear in rtx X. */
+
+static void
+get_pattern_stats_1 (struct pattern_stats *stats, rtx x)
+{
+ RTX_CODE code;
+ int i;
+ int len;
+ const char *fmt;
+
+ if (x == NULL_RTX)
+ return;
+
+ code = GET_CODE (x);
+ switch (code)
+ {
+ case MATCH_OPERAND:
+ case MATCH_OPERATOR:
+ case MATCH_PARALLEL:
+ stats->max_opno = MAX (stats->max_opno, XINT (x, 0));
+ break;
+
+ case MATCH_DUP:
+ case MATCH_OP_DUP:
+ case MATCH_PAR_DUP:
+ stats->num_dups++;
+ stats->max_dup_opno = MAX (stats->max_dup_opno, XINT (x, 0));
+ break;
+
+ case MATCH_SCRATCH:
+ stats->max_scratch_opno = MAX (stats->max_scratch_opno, XINT (x, 0));
+ break;
+
+ default:
+ break;
+ }
+
+ fmt = GET_RTX_FORMAT (code);
+ len = GET_RTX_LENGTH (code);
+ for (i = 0; i < len; i++)
+ {
+ if (fmt[i] == 'e' || fmt[i] == 'u')
+ get_pattern_stats_1 (stats, XEXP (x, i));
+ else if (fmt[i] == 'E')
+ {
+ int j;
+ for (j = 0; j < XVECLEN (x, i); j++)
+ get_pattern_stats_1 (stats, XVECEXP (x, i, j));
+ }
+ }
+}
+
+/* Make STATS describe the operands that appear in instruction pattern
+ PATTERN. */
+
+void
+get_pattern_stats (struct pattern_stats *stats, rtvec pattern)
+{
+ int i, len;
+
+ stats->max_opno = -1;
+ stats->max_dup_opno = -1;
+ stats->max_scratch_opno = -1;
+ stats->num_dups = 0;
+
+ len = GET_NUM_ELEM (pattern);
+ for (i = 0; i < len; i++)
+ get_pattern_stats_1 (stats, RTVEC_ELT (pattern, i));
+
+ stats->num_generator_args = stats->max_opno + 1;
+ stats->num_insn_operands = MAX (stats->max_opno,
+ stats->max_scratch_opno) + 1;
+ stats->num_operand_vars = MAX (stats->max_opno,
+ MAX (stats->max_dup_opno,
+ stats->max_scratch_opno)) + 1;
+}
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