1 /* Translation of constants
2 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Paul Brook
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
22 /* trans-const.c -- convert constant values */
26 #include "coretypes.h"
33 #include "trans-const.h"
34 #include "trans-types.h"
36 /* String constants. */
37 tree gfc_strconst_bounds;
38 tree gfc_strconst_fault;
39 tree gfc_strconst_wrong_return;
40 tree gfc_strconst_current_filename;
42 tree gfc_rank_cst[GFC_MAX_DIMENSIONS + 1];
44 /* Build a constant with given type from an int_cst. */
47 gfc_build_const (tree type, tree intval)
52 switch (TREE_CODE (type))
55 val = convert (type, intval);
59 val = build_real_from_int_cst (type, intval);
63 val = build_real_from_int_cst (TREE_TYPE (type), intval);
64 zero = build_real_from_int_cst (TREE_TYPE (type), integer_zero_node);
65 val = build_complex (type, val, zero);
75 gfc_build_string_const (int length, const char *s)
80 str = build_string (length, s);
81 len = build_int_cst (NULL_TREE, length);
83 build_array_type (gfc_character1_type_node,
84 build_range_type (gfc_charlen_type_node,
85 integer_one_node, len));
89 /* Build a Fortran character constant from a zero-terminated string. */
92 gfc_build_cstring_const (const char *s)
94 return gfc_build_string_const (strlen (s) + 1, s);
97 /* Return a string constant with the given length. Used for static
98 initializers. The constant will be padded or truncated to match
102 gfc_conv_string_init (tree length, gfc_expr * expr)
109 gcc_assert (expr->expr_type == EXPR_CONSTANT);
110 gcc_assert (expr->ts.type == BT_CHARACTER && expr->ts.kind == 1);
111 gcc_assert (INTEGER_CST_P (length));
112 gcc_assert (TREE_INT_CST_HIGH (length) == 0);
114 len = TREE_INT_CST_LOW (length);
115 slen = expr->value.character.length;
119 s = gfc_getmem (len);
120 memcpy (s, expr->value.character.string, slen);
121 memset (&s[slen], ' ', len - slen);
122 str = gfc_build_string_const (len, s);
126 str = gfc_build_string_const (len, expr->value.character.string);
132 /* Create a tree node for the string length if it is constant. */
135 gfc_conv_const_charlen (gfc_charlen * cl)
137 if (cl->backend_decl)
140 if (cl->length && cl->length->expr_type == EXPR_CONSTANT)
142 cl->backend_decl = gfc_conv_mpz_to_tree (cl->length->value.integer,
143 cl->length->ts.kind);
144 cl->backend_decl = fold_convert (gfc_charlen_type_node,
150 gfc_init_constants (void)
154 for (n = 0; n <= GFC_MAX_DIMENSIONS; n++)
155 gfc_rank_cst[n] = build_int_cst (gfc_array_index_type, n);
157 gfc_strconst_bounds = gfc_build_cstring_const ("Array bound mismatch");
160 gfc_build_cstring_const ("Array reference out of bounds");
162 gfc_strconst_wrong_return =
163 gfc_build_cstring_const ("Incorrect function return value");
165 gfc_strconst_current_filename =
166 gfc_build_cstring_const (gfc_option.source);
169 /* Converts a GMP integer into a backend tree node. */
171 gfc_conv_mpz_to_tree (mpz_t i, int kind)
174 unsigned HOST_WIDE_INT low;
176 if (mpz_fits_slong_p (i))
178 /* Note that HOST_WIDE_INT is never smaller than long. */
179 low = mpz_get_si (i);
180 high = mpz_sgn (i) < 0 ? -1 : 0;
184 unsigned HOST_WIDE_INT words[2];
187 /* Since we know that the value is not zero (mpz_fits_slong_p),
188 we know that at least one word will be written, but we don't know
189 about the second. It's quicker to zero the second word before
190 than conditionally clear it later. */
193 /* Extract the absolute value into words. */
194 mpz_export (words, &count, -1, sizeof (HOST_WIDE_INT), 0, 0, i);
196 /* We assume that all numbers are in range for its type, and that
197 we never create a type larger than 2*HWI, which is the largest
198 that the middle-end can handle. */
199 gcc_assert (count == 1 || count == 2);
204 /* Negate if necessary. */
210 low = -low, high = ~high;
214 return build_int_cst_wide (gfc_get_int_type (kind), low, high);
217 /* Converts a real constant into backend form. Uses an intermediate string
221 gfc_conv_mpfr_to_tree (mpfr_t f, int kind)
229 n = gfc_validate_kind (BT_REAL, kind, false);
231 gcc_assert (gfc_real_kinds[n].radix == 2);
233 /* mpfr chooses too small a number of hexadecimal digits if the
234 number of binary digits is not divisible by four, therefore we
235 have to explicitly request a sufficient number of digits here. */
236 p = mpfr_get_str (NULL, &exp, 16, gfc_real_kinds[n].digits / 4 + 1,
239 /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp,
240 mpfr_get_str returns the exponent for mantissa * 16**exp, adjust
244 /* The additional 12 characters add space for the sprintf below.
245 This leaves 6 digits for the exponent which is certainly enough. */
246 q = (char *) gfc_getmem (strlen (p) + 12);
249 sprintf (q, "-0x.%sp%d", &p[1], (int) exp);
251 sprintf (q, "0x.%sp%d", p, (int) exp);
253 type = gfc_get_real_type (kind);
254 res = build_real (type, REAL_VALUE_ATOF (q, TYPE_MODE (type)));
263 /* Translate any literal constant to a tree. Constants never have
264 pre or post chains. Character literal constants are special
265 special because they have a value and a length, so they cannot be
266 returned as a single tree. It is up to the caller to set the
267 length somewhere if necessary.
269 Returns the translated constant, or aborts if it gets a type it
273 gfc_conv_constant_to_tree (gfc_expr * expr)
275 gcc_assert (expr->expr_type == EXPR_CONSTANT);
277 /* If it is converted from Hollerith constant, we build string constant
278 and VIEW_CONVERT to its type. */
280 switch (expr->ts.type)
284 return build1 (VIEW_CONVERT_EXPR,
285 gfc_get_int_type (expr->ts.kind),
286 gfc_build_string_const (expr->value.character.length,
287 expr->value.character.string));
289 return gfc_conv_mpz_to_tree (expr->value.integer, expr->ts.kind);
293 return build1 (VIEW_CONVERT_EXPR,
294 gfc_get_real_type (expr->ts.kind),
295 gfc_build_string_const (expr->value.character.length,
296 expr->value.character.string));
298 return gfc_conv_mpfr_to_tree (expr->value.real, expr->ts.kind);
302 return build1 (VIEW_CONVERT_EXPR,
303 gfc_get_logical_type (expr->ts.kind),
304 gfc_build_string_const (expr->value.character.length,
305 expr->value.character.string));
307 return build_int_cst (gfc_get_logical_type (expr->ts.kind),
308 expr->value.logical);
312 return build1 (VIEW_CONVERT_EXPR,
313 gfc_get_complex_type (expr->ts.kind),
314 gfc_build_string_const (expr->value.character.length,
315 expr->value.character.string));
318 tree real = gfc_conv_mpfr_to_tree (expr->value.complex.r,
320 tree imag = gfc_conv_mpfr_to_tree (expr->value.complex.i,
323 return build_complex (gfc_typenode_for_spec (&expr->ts),
329 return gfc_build_string_const (expr->value.character.length,
330 expr->value.character.string);
333 fatal_error ("gfc_conv_constant_to_tree(): invalid type: %s",
334 gfc_typename (&expr->ts));
339 /* Like gfc_conv_constant_to_tree, but for a simplified expression.
340 We can handle character literal constants here as well. */
343 gfc_conv_constant (gfc_se * se, gfc_expr * expr)
345 gcc_assert (expr->expr_type == EXPR_CONSTANT);
349 gcc_assert (se->ss != gfc_ss_terminator);
350 gcc_assert (se->ss->type == GFC_SS_SCALAR);
351 gcc_assert (se->ss->expr == expr);
353 se->expr = se->ss->data.scalar.expr;
354 se->string_length = se->ss->string_length;
355 gfc_advance_se_ss_chain (se);
359 /* Translate the constant and put it in the simplifier structure. */
360 se->expr = gfc_conv_constant_to_tree (expr);
362 /* If this is a CHARACTER string, set its length in the simplifier
364 if (expr->ts.type == BT_CHARACTER)
365 se->string_length = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (se->expr)));