/* Generate code from machine description to recognize rtl as insns.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GCC.
/* The line number of the start of the pattern currently being processed. */
static int pattern_lineno;
\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. */
-static void
-compute_predicate_codes (rtx exp, 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), 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')
- {
- error_with_line (pattern_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 (pattern_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 (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)
- {
- error_with_line (pattern_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 (pattern_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
-
-/* 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)
-{
- struct pred_data *pred = XCNEW (struct pred_data);
- char codes[NUM_RTX_CODE];
- int i;
-
- pred->name = XSTR (desc, 0);
- if (GET_CODE (desc) == DEFINE_SPECIAL_PREDICATE)
- pred->special = 1;
-
- compute_predicate_codes (XEXP (desc, 1), 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
static struct decision *new_decision
(const char *, struct decision_head *);
static struct decision_test *new_decision_test
#include \"hard-reg-set.h\"\n\
#include \"resource.h\"\n\
#include \"diagnostic-core.h\"\n\
-#include \"toplev.h\"\n\
#include \"reload.h\"\n\
#include \"regs.h\"\n\
#include \"tm-constrs.h\"\n\
switch (GET_CODE (desc))
{
- case DEFINE_PREDICATE:
- case DEFINE_SPECIAL_PREDICATE:
- process_define_predicate (desc);
- break;
-
case DEFINE_INSN:
h = make_insn_sequence (desc, RECOG);
merge_trees (&recog_tree, &h);
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