gcc/machmode.h

   1 /* Machine mode definitions for GCC; included by rtl.h and tree.h.
   2    Copyright (C) 1991-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef HAVE_MACHINE_MODES
  21 #define HAVE_MACHINE_MODES
  22
  23 extern CONST_MODE_SIZE unsigned short mode_size[NUM_MACHINE_MODES];
  24 extern const unsigned short mode_precision[NUM_MACHINE_MODES];
  25 extern const unsigned char mode_inner[NUM_MACHINE_MODES];
  26 extern const unsigned char mode_nunits[NUM_MACHINE_MODES];
  27 extern CONST_MODE_UNIT_SIZE unsigned char mode_unit_size[NUM_MACHINE_MODES];
  28 extern const unsigned short mode_unit_precision[NUM_MACHINE_MODES];
  29 extern const unsigned char mode_wider[NUM_MACHINE_MODES];
  30 extern const unsigned char mode_2xwider[NUM_MACHINE_MODES];
  31
  32 template<typename T>
  33 struct mode_traits
  34 {
  35   /* For use by the machmode support code only.
  36
  37      There are cases in which the machmode support code needs to forcibly
  38      convert a machine_mode to a specific mode class T, and in which the
  39      context guarantees that this is valid without the need for an assert.
  40      This can be done using:
  41
  42        return typename mode_traits<T>::from_int (mode);
  43
  44      when returning a T and:
  45
  46        res = T (typename mode_traits<T>::from_int (mode));
  47
  48      when assigning to a value RES that must be assignment-compatible
  49      with (but possibly not the same as) T.  */
  50 #ifdef USE_ENUM_MODES
  51   /* Allow direct conversion of enums to specific mode classes only
  52      when USE_ENUM_MODES is defined.  This is only intended for use
  53      by gencondmd, so that it can tell more easily when .md conditions
  54      are always false.  */
  55   typedef machine_mode from_int;
  56 #else
  57   /* Here we use an enum type distinct from machine_mode but with the
  58      same range as machine_mode.  T should have a constructor that
  59      accepts this enum type; it should not have a constructor that
  60      accepts machine_mode.
  61
  62      We use this somewhat indirect approach to avoid too many constructor
  63      calls when the compiler is built with -O0.  For example, even in
  64      unoptimized code, the return statement above would construct the
  65      returned T directly from the numerical value of MODE.  */
  66   enum from_int { dummy = MAX_MACHINE_MODE };
  67 #endif
  68 };
  69
  70 template<>
  71 struct mode_traits<machine_mode>
  72 {
  73   /* machine_mode itself needs no conversion.  */
  74   typedef machine_mode from_int;
  75 };
  76
  77 /* Get the name of mode MODE as a string.  */
  78
  79 extern const char * const mode_name[NUM_MACHINE_MODES];
  80 #define GET_MODE_NAME(MODE)  mode_name[MODE]
  81
  82 /* Mode classes.  */
  83
  84 #include "mode-classes.def"
  85 #define DEF_MODE_CLASS(M) M
  86 enum mode_class { MODE_CLASSES, MAX_MODE_CLASS };
  87 #undef DEF_MODE_CLASS
  88 #undef MODE_CLASSES
  89
  90 /* Get the general kind of object that mode MODE represents
  91    (integer, floating, complex, etc.)  */
  92
  93 extern const unsigned char mode_class[NUM_MACHINE_MODES];
  94 #define GET_MODE_CLASS(MODE)  ((enum mode_class) mode_class[MODE])
  95
  96 /* Nonzero if MODE is an integral mode.  */
  97 #define INTEGRAL_MODE_P(MODE)                   \
  98   (GET_MODE_CLASS (MODE) == MODE_INT            \
  99    || GET_MODE_CLASS (MODE) == MODE_PARTIAL_INT \
 100    || GET_MODE_CLASS (MODE) == MODE_COMPLEX_INT \
 101    || GET_MODE_CLASS (MODE) == MODE_VECTOR_INT)
 102
 103 /* Nonzero if MODE is a floating-point mode.  */
 104 #define FLOAT_MODE_P(MODE)              \
 105   (GET_MODE_CLASS (MODE) == MODE_FLOAT  \
 106    || GET_MODE_CLASS (MODE) == MODE_DECIMAL_FLOAT \
 107    || GET_MODE_CLASS (MODE) == MODE_COMPLEX_FLOAT \
 108    || GET_MODE_CLASS (MODE) == MODE_VECTOR_FLOAT)
 109
 110 /* Nonzero if MODE is a complex mode.  */
 111 #define COMPLEX_MODE_P(MODE)                    \
 112   (GET_MODE_CLASS (MODE) == MODE_COMPLEX_INT    \
 113    || GET_MODE_CLASS (MODE) == MODE_COMPLEX_FLOAT)
 114
 115 /* Nonzero if MODE is a vector mode.  */
 116 #define VECTOR_MODE_P(MODE)                     \
 117   (GET_MODE_CLASS (MODE) == MODE_VECTOR_INT     \
 118    || GET_MODE_CLASS (MODE) == MODE_VECTOR_FLOAT        \
 119    || GET_MODE_CLASS (MODE) == MODE_VECTOR_FRACT        \
 120    || GET_MODE_CLASS (MODE) == MODE_VECTOR_UFRACT       \
 121    || GET_MODE_CLASS (MODE) == MODE_VECTOR_ACCUM        \
 122    || GET_MODE_CLASS (MODE) == MODE_VECTOR_UACCUM)
 123
 124 /* Nonzero if MODE is a scalar integral mode.  */
 125 #define SCALAR_INT_MODE_P(MODE)                 \
 126   (GET_MODE_CLASS (MODE) == MODE_INT            \
 127    || GET_MODE_CLASS (MODE) == MODE_PARTIAL_INT)
 128
 129 /* Nonzero if MODE is a scalar floating point mode.  */
 130 #define SCALAR_FLOAT_MODE_P(MODE)               \
 131   (GET_MODE_CLASS (MODE) == MODE_FLOAT          \
 132    || GET_MODE_CLASS (MODE) == MODE_DECIMAL_FLOAT)
 133
 134 /* Nonzero if MODE is a decimal floating point mode.  */
 135 #define DECIMAL_FLOAT_MODE_P(MODE)              \
 136   (GET_MODE_CLASS (MODE) == MODE_DECIMAL_FLOAT)
 137
 138 /* Nonzero if MODE is a scalar fract mode.  */
 139 #define SCALAR_FRACT_MODE_P(MODE)       \
 140   (GET_MODE_CLASS (MODE) == MODE_FRACT)
 141
 142 /* Nonzero if MODE is a scalar ufract mode.  */
 143 #define SCALAR_UFRACT_MODE_P(MODE)      \
 144   (GET_MODE_CLASS (MODE) == MODE_UFRACT)
 145
 146 /* Nonzero if MODE is a scalar fract or ufract mode.  */
 147 #define ALL_SCALAR_FRACT_MODE_P(MODE)   \
 148   (SCALAR_FRACT_MODE_P (MODE) || SCALAR_UFRACT_MODE_P (MODE))
 149
 150 /* Nonzero if MODE is a scalar accum mode.  */
 151 #define SCALAR_ACCUM_MODE_P(MODE)       \
 152   (GET_MODE_CLASS (MODE) == MODE_ACCUM)
 153
 154 /* Nonzero if MODE is a scalar uaccum mode.  */
 155 #define SCALAR_UACCUM_MODE_P(MODE)      \
 156   (GET_MODE_CLASS (MODE) == MODE_UACCUM)
 157
 158 /* Nonzero if MODE is a scalar accum or uaccum mode.  */
 159 #define ALL_SCALAR_ACCUM_MODE_P(MODE)   \
 160   (SCALAR_ACCUM_MODE_P (MODE) || SCALAR_UACCUM_MODE_P (MODE))
 161
 162 /* Nonzero if MODE is a scalar fract or accum mode.  */
 163 #define SIGNED_SCALAR_FIXED_POINT_MODE_P(MODE)  \
 164   (SCALAR_FRACT_MODE_P (MODE) || SCALAR_ACCUM_MODE_P (MODE))
 165
 166 /* Nonzero if MODE is a scalar ufract or uaccum mode.  */
 167 #define UNSIGNED_SCALAR_FIXED_POINT_MODE_P(MODE)        \
 168   (SCALAR_UFRACT_MODE_P (MODE) || SCALAR_UACCUM_MODE_P (MODE))
 169
 170 /* Nonzero if MODE is a scalar fract, ufract, accum or uaccum mode.  */
 171 #define ALL_SCALAR_FIXED_POINT_MODE_P(MODE)     \
 172   (SIGNED_SCALAR_FIXED_POINT_MODE_P (MODE)      \
 173    || UNSIGNED_SCALAR_FIXED_POINT_MODE_P (MODE))
 174
 175 /* Nonzero if MODE is a scalar/vector fract mode.  */
 176 #define FRACT_MODE_P(MODE)              \
 177   (GET_MODE_CLASS (MODE) == MODE_FRACT  \
 178    || GET_MODE_CLASS (MODE) == MODE_VECTOR_FRACT)
 179
 180 /* Nonzero if MODE is a scalar/vector ufract mode.  */
 181 #define UFRACT_MODE_P(MODE)             \
 182   (GET_MODE_CLASS (MODE) == MODE_UFRACT \
 183    || GET_MODE_CLASS (MODE) == MODE_VECTOR_UFRACT)
 184
 185 /* Nonzero if MODE is a scalar/vector fract or ufract mode.  */
 186 #define ALL_FRACT_MODE_P(MODE)          \
 187   (FRACT_MODE_P (MODE) || UFRACT_MODE_P (MODE))
 188
 189 /* Nonzero if MODE is a scalar/vector accum mode.  */
 190 #define ACCUM_MODE_P(MODE)              \
 191   (GET_MODE_CLASS (MODE) == MODE_ACCUM  \
 192    || GET_MODE_CLASS (MODE) == MODE_VECTOR_ACCUM)
 193
 194 /* Nonzero if MODE is a scalar/vector uaccum mode.  */
 195 #define UACCUM_MODE_P(MODE)             \
 196   (GET_MODE_CLASS (MODE) == MODE_UACCUM \
 197    || GET_MODE_CLASS (MODE) == MODE_VECTOR_UACCUM)
 198
 199 /* Nonzero if MODE is a scalar/vector accum or uaccum mode.  */
 200 #define ALL_ACCUM_MODE_P(MODE)          \
 201   (ACCUM_MODE_P (MODE) || UACCUM_MODE_P (MODE))
 202
 203 /* Nonzero if MODE is a scalar/vector fract or accum mode.  */
 204 #define SIGNED_FIXED_POINT_MODE_P(MODE)         \
 205   (FRACT_MODE_P (MODE) || ACCUM_MODE_P (MODE))
 206
 207 /* Nonzero if MODE is a scalar/vector ufract or uaccum mode.  */
 208 #define UNSIGNED_FIXED_POINT_MODE_P(MODE)       \
 209   (UFRACT_MODE_P (MODE) || UACCUM_MODE_P (MODE))
 210
 211 /* Nonzero if MODE is a scalar/vector fract, ufract, accum or uaccum mode.  */
 212 #define ALL_FIXED_POINT_MODE_P(MODE)            \
 213   (SIGNED_FIXED_POINT_MODE_P (MODE)             \
 214    || UNSIGNED_FIXED_POINT_MODE_P (MODE))
 215
 216 /* Nonzero if CLASS modes can be widened.  */
 217 #define CLASS_HAS_WIDER_MODES_P(CLASS)         \
 218   (CLASS == MODE_INT                           \
 219    || CLASS == MODE_PARTIAL_INT                \
 220    || CLASS == MODE_FLOAT                      \
 221    || CLASS == MODE_DECIMAL_FLOAT              \
 222    || CLASS == MODE_COMPLEX_FLOAT              \
 223    || CLASS == MODE_FRACT                      \
 224    || CLASS == MODE_UFRACT                     \
 225    || CLASS == MODE_ACCUM                      \
 226    || CLASS == MODE_UACCUM)
 227
 228 #define POINTER_BOUNDS_MODE_P(MODE)      \
 229   (GET_MODE_CLASS (MODE) == MODE_POINTER_BOUNDS)
 230
 231 /* An optional T (i.e. a T or nothing), where T is some form of mode class.  */
 232 template<typename T>
 233 class opt_mode
 234 {
 235 public:
 236   enum from_int { dummy = MAX_MACHINE_MODE };
 237
 238   ALWAYS_INLINE opt_mode () : m_mode (E_VOIDmode) {}
 239   ALWAYS_INLINE opt_mode (const T &m) : m_mode (m) {}
 240   ALWAYS_INLINE opt_mode (from_int m) : m_mode (machine_mode (m)) {}
 241
 242   machine_mode else_void () const;
 243   T require () const;
 244
 245   bool exists () const;
 246   template<typename U> bool exists (U *) const;
 247
 248 private:
 249   machine_mode m_mode;
 250 };
 251
 252 /* If the object contains a T, return its enum value, otherwise return
 253    E_VOIDmode.  */
 254
 255 template<typename T>
 256 ALWAYS_INLINE machine_mode
 257 opt_mode<T>::else_void () const
 258 {
 259   return m_mode;
 260 }
 261
 262 /* Assert that the object contains a T and return it.  */
 263
 264 template<typename T>
 265 inline T
 266 opt_mode<T>::require () const
 267 {
 268   gcc_checking_assert (m_mode != E_VOIDmode);
 269   return typename mode_traits<T>::from_int (m_mode);
 270 }
 271
 272 /* Return true if the object contains a T rather than nothing.  */
 273
 274 template<typename T>
 275 ALWAYS_INLINE bool
 276 opt_mode<T>::exists () const
 277 {
 278   return m_mode != E_VOIDmode;
 279 }
 280
 281 /* Return true if the object contains a T, storing it in *MODE if so.  */
 282
 283 template<typename T>
 284 template<typename U>
 285 inline bool
 286 opt_mode<T>::exists (U *mode) const
 287 {
 288   if (m_mode != E_VOIDmode)
 289     {
 290       *mode = T (typename mode_traits<T>::from_int (m_mode));
 291       return true;
 292     }
 293   return false;
 294 }
 295
 296 /* Return true if mode M has type T.  */
 297
 298 template<typename T>
 299 inline bool
 300 is_a (machine_mode m)
 301 {
 302   return T::includes_p (m);
 303 }
 304
 305 /* Assert that mode M has type T, and return it in that form.  */
 306
 307 template<typename T>
 308 inline T
 309 as_a (machine_mode m)
 310 {
 311   gcc_checking_assert (T::includes_p (m));
 312   return typename mode_traits<T>::from_int (m);
 313 }
 314
 315 /* Convert M to an opt_mode<T>.  */
 316
 317 template<typename T>
 318 inline opt_mode<T>
 319 dyn_cast (machine_mode m)
 320 {
 321   if (T::includes_p (m))
 322     return T (typename mode_traits<T>::from_int (m));
 323   return opt_mode<T> ();
 324 }
 325
 326 /* Return true if mode M has type T, storing it as a T in *RESULT
 327    if so.  */
 328
 329 template<typename T, typename U>
 330 inline bool
 331 is_a (machine_mode m, U *result)
 332 {
 333   if (T::includes_p (m))
 334     {
 335       *result = T (typename mode_traits<T>::from_int (m));
 336       return true;
 337     }
 338   return false;
 339 }
 340
 341 /* Represents a machine mode that is known to be a SCALAR_INT_MODE_P.  */
 342 class scalar_int_mode
 343 {
 344 public:
 345   typedef mode_traits<scalar_int_mode>::from_int from_int;
 346
 347   ALWAYS_INLINE scalar_int_mode () {}
 348   ALWAYS_INLINE scalar_int_mode (from_int m) : m_mode (machine_mode (m)) {}
 349   ALWAYS_INLINE operator machine_mode () const { return m_mode; }
 350
 351   static bool includes_p (machine_mode);
 352
 353 protected:
 354   machine_mode m_mode;
 355 };
 356
 357 /* Return true if M is a scalar_int_mode.  */
 358
 359 inline bool
 360 scalar_int_mode::includes_p (machine_mode m)
 361 {
 362   return SCALAR_INT_MODE_P (m);
 363 }
 364
 365 /* Represents a machine mode that is known to be a SCALAR_FLOAT_MODE_P.  */
 366 class scalar_float_mode
 367 {
 368 public:
 369   typedef mode_traits<scalar_float_mode>::from_int from_int;
 370
 371   ALWAYS_INLINE scalar_float_mode () {}
 372   ALWAYS_INLINE scalar_float_mode (from_int m) : m_mode (machine_mode (m)) {}
 373   ALWAYS_INLINE operator machine_mode () const { return m_mode; }
 374
 375   static bool includes_p (machine_mode);
 376
 377 protected:
 378   machine_mode m_mode;
 379 };
 380
 381 /* Return true if M is a scalar_float_mode.  */
 382
 383 inline bool
 384 scalar_float_mode::includes_p (machine_mode m)
 385 {
 386   return SCALAR_FLOAT_MODE_P (m);
 387 }
 388
 389 /* Return the base GET_MODE_SIZE value for MODE.  */
 390
 391 ALWAYS_INLINE unsigned short
 392 mode_to_bytes (machine_mode mode)
 393 {
 394 #if GCC_VERSION >= 4001
 395   return (__builtin_constant_p (mode)
 396           ? mode_size_inline (mode) : mode_size[mode]);
 397 #else
 398   return mode_size[mode];
 399 #endif
 400 }
 401
 402 /* Return the base GET_MODE_BITSIZE value for MODE.  */
 403
 404 ALWAYS_INLINE unsigned short
 405 mode_to_bits (machine_mode mode)
 406 {
 407   return mode_to_bytes (mode) * BITS_PER_UNIT;
 408 }
 409
 410 /* Return the base GET_MODE_PRECISION value for MODE.  */
 411
 412 ALWAYS_INLINE unsigned short
 413 mode_to_precision (machine_mode mode)
 414 {
 415   return mode_precision[mode];
 416 }
 417
 418 /* Return the base GET_MODE_INNER value for MODE.  */
 419
 420 ALWAYS_INLINE machine_mode
 421 mode_to_inner (machine_mode mode)
 422 {
 423 #if GCC_VERSION >= 4001
 424   return (machine_mode) (__builtin_constant_p (mode)
 425                          ? mode_inner_inline (mode) : mode_inner[mode]);
 426 #else
 427   return (machine_mode) mode_inner[mode];
 428 #endif
 429 }
 430
 431 /* Return the base GET_MODE_UNIT_SIZE value for MODE.  */
 432
 433 ALWAYS_INLINE unsigned char
 434 mode_to_unit_size (machine_mode mode)
 435 {
 436 #if GCC_VERSION >= 4001
 437   return (__builtin_constant_p (mode)
 438           ? mode_unit_size_inline (mode) : mode_unit_size[mode]);
 439 #else
 440   return mode_unit_size[mode];
 441 #endif
 442 }
 443
 444 /* Return the base GET_MODE_UNIT_PRECISION value for MODE.  */
 445
 446 ALWAYS_INLINE unsigned short
 447 mode_to_unit_precision (machine_mode mode)
 448 {
 449 #if GCC_VERSION >= 4001
 450   return (__builtin_constant_p (mode)
 451           ? mode_unit_precision_inline (mode) : mode_unit_precision[mode]);
 452 #else
 453   return mode_unit_precision[mode];
 454 #endif
 455 }
 456
 457 /* Return the base GET_MODE_NUNITS value for MODE.  */
 458
 459 ALWAYS_INLINE unsigned short
 460 mode_to_nunits (machine_mode mode)
 461 {
 462 #if GCC_VERSION >= 4001
 463   return (__builtin_constant_p (mode)
 464           ? mode_nunits_inline (mode) : mode_nunits[mode]);
 465 #else
 466   return mode_nunits[mode];
 467 #endif
 468 }
 469
 470 /* Get the size in bytes of an object of mode MODE.  */
 471
 472 #define GET_MODE_SIZE(MODE) (mode_to_bytes (MODE))
 473
 474 /* Get the size in bits of an object of mode MODE.  */
 475
 476 #define GET_MODE_BITSIZE(MODE) (mode_to_bits (MODE))
 477
 478 /* Get the number of value bits of an object of mode MODE.  */
 479
 480 #define GET_MODE_PRECISION(MODE) (mode_to_precision (MODE))
 481
 482 /* Get the number of integral bits of an object of mode MODE.  */
 483 extern CONST_MODE_IBIT unsigned char mode_ibit[NUM_MACHINE_MODES];
 484 #define GET_MODE_IBIT(MODE) mode_ibit[MODE]
 485
 486 /* Get the number of fractional bits of an object of mode MODE.  */
 487 extern CONST_MODE_FBIT unsigned char mode_fbit[NUM_MACHINE_MODES];
 488 #define GET_MODE_FBIT(MODE) mode_fbit[MODE]
 489
 490 /* Get a bitmask containing 1 for all bits in a word
 491    that fit within mode MODE.  */
 492
 493 extern const unsigned HOST_WIDE_INT mode_mask_array[NUM_MACHINE_MODES];
 494
 495 #define GET_MODE_MASK(MODE) mode_mask_array[MODE]
 496
 497 /* Return the mode of the basic parts of MODE.  For vector modes this is the
 498    mode of the vector elements.  For complex modes it is the mode of the real
 499    and imaginary parts.  For other modes it is MODE itself.  */
 500
 501 #define GET_MODE_INNER(MODE) (mode_to_inner (MODE))
 502
 503 /* Get the size in bytes or bits of the basic parts of an
 504    object of mode MODE.  */
 505
 506 #define GET_MODE_UNIT_SIZE(MODE) mode_to_unit_size (MODE)
 507
 508 #define GET_MODE_UNIT_BITSIZE(MODE) \
 509   ((unsigned short) (GET_MODE_UNIT_SIZE (MODE) * BITS_PER_UNIT))
 510
 511 #define GET_MODE_UNIT_PRECISION(MODE) (mode_to_unit_precision (MODE))
 512
 513 /* Get the number of units in an object of mode MODE.  This is 2 for
 514    complex modes and the number of elements for vector modes.  */
 515
 516 #define GET_MODE_NUNITS(MODE) (mode_to_nunits (MODE))
 517
 518 /* Get the next wider natural mode (eg, QI -> HI -> SI -> DI -> TI).  */
 519
 520 template<typename T>
 521 ALWAYS_INLINE opt_mode<T>
 522 GET_MODE_WIDER_MODE (const T &m)
 523 {
 524   return typename opt_mode<T>::from_int (mode_wider[m]);
 525 }
 526
 527 /* For scalars, this is a mode with twice the precision.  For vectors,
 528    this is a mode with the same inner mode but with twice the elements.  */
 529
 530 template<typename T>
 531 ALWAYS_INLINE opt_mode<T>
 532 GET_MODE_2XWIDER_MODE (const T &m)
 533 {
 534   return typename opt_mode<T>::from_int (mode_2xwider[m]);
 535 }
 536
 537 /* Get the complex mode from the component mode.  */
 538 extern const unsigned char mode_complex[NUM_MACHINE_MODES];
 539 #define GET_MODE_COMPLEX_MODE(MODE) ((machine_mode) mode_complex[MODE])
 540
 541 /* Return the mode for data of a given size SIZE and mode class CLASS.
 542    If LIMIT is nonzero, then don't use modes bigger than MAX_FIXED_MODE_SIZE.
 543    The value is BLKmode if no other mode is found.  */
 544
 545 extern machine_mode mode_for_size (unsigned int, enum mode_class, int);
 546
 547 /* Return the machine mode to use for a MODE_FLOAT of SIZE bits, if one
 548    exists.  */
 549
 550 inline opt_scalar_float_mode
 551 float_mode_for_size (unsigned int size)
 552 {
 553   return dyn_cast <scalar_float_mode> (mode_for_size (size, MODE_FLOAT, 0));
 554 }
 555
 556 /* Similar to mode_for_size, but find the smallest mode for a given width.  */
 557
 558 extern machine_mode smallest_mode_for_size (unsigned int,
 559                                                  enum mode_class);
 560
 561
 562 /* Return an integer mode of the exact same size as the input mode,
 563    or BLKmode on failure.  */
 564
 565 extern machine_mode int_mode_for_mode (machine_mode);
 566
 567 extern machine_mode bitwise_mode_for_mode (machine_mode);
 568
 569 /* Return a mode that is suitable for representing a vector,
 570    or BLKmode on failure.  */
 571
 572 extern machine_mode mode_for_vector (machine_mode, unsigned);
 573
 574 /* A class for iterating through possible bitfield modes.  */
 575 class bit_field_mode_iterator
 576 {
 577 public:
 578   bit_field_mode_iterator (HOST_WIDE_INT, HOST_WIDE_INT,
 579                            HOST_WIDE_INT, HOST_WIDE_INT,
 580                            unsigned int, bool);
 581   bool next_mode (machine_mode *);
 582   bool prefer_smaller_modes ();
 583
 584 private:
 585   machine_mode m_mode;
 586   /* We use signed values here because the bit position can be negative
 587      for invalid input such as gcc.dg/pr48335-8.c.  */
 588   HOST_WIDE_INT m_bitsize;
 589   HOST_WIDE_INT m_bitpos;
 590   HOST_WIDE_INT m_bitregion_start;
 591   HOST_WIDE_INT m_bitregion_end;
 592   unsigned int m_align;
 593   bool m_volatilep;
 594   int m_count;
 595 };
 596
 597 /* Find the best mode to use to access a bit field.  */
 598
 599 extern machine_mode get_best_mode (int, int,
 600                                         unsigned HOST_WIDE_INT,
 601                                         unsigned HOST_WIDE_INT,
 602                                         unsigned int,
 603                                         machine_mode, bool);
 604
 605 /* Determine alignment, 1<=result<=BIGGEST_ALIGNMENT.  */
 606
 607 extern CONST_MODE_BASE_ALIGN unsigned short mode_base_align[NUM_MACHINE_MODES];
 608
 609 extern unsigned get_mode_alignment (machine_mode);
 610
 611 #define GET_MODE_ALIGNMENT(MODE) get_mode_alignment (MODE)
 612
 613 /* For each class, get the narrowest mode in that class.  */
 614
 615 extern const unsigned char class_narrowest_mode[MAX_MODE_CLASS];
 616 #define GET_CLASS_NARROWEST_MODE(CLASS) \
 617   ((machine_mode) class_narrowest_mode[CLASS])
 618
 619 /* Return the narrowest mode in T's class.  */
 620
 621 template<typename T>
 622 inline T
 623 get_narrowest_mode (T mode)
 624 {
 625   return typename mode_traits<T>::from_int
 626     (class_narrowest_mode[GET_MODE_CLASS (mode)]);
 627 }
 628
 629 /* Define the integer modes whose sizes are BITS_PER_UNIT and BITS_PER_WORD
 630    and the mode whose class is Pmode and whose size is POINTER_SIZE.  */
 631
 632 extern scalar_int_mode byte_mode;
 633 extern scalar_int_mode word_mode;
 634 extern scalar_int_mode ptr_mode;
 635
 636 /* Target-dependent machine mode initialization - in insn-modes.c.  */
 637 extern void init_adjust_machine_modes (void);
 638
 639 #define TRULY_NOOP_TRUNCATION_MODES_P(MODE1, MODE2) \
 640   TRULY_NOOP_TRUNCATION (GET_MODE_PRECISION (MODE1), \
 641                          GET_MODE_PRECISION (MODE2))
 642
 643 #define HWI_COMPUTABLE_MODE_P(MODE) \
 644   (SCALAR_INT_MODE_P (MODE) \
 645    && GET_MODE_PRECISION (MODE) <= HOST_BITS_PER_WIDE_INT)
 646
 647 struct int_n_data_t {
 648   /* These parts are initailized by genmodes output */
 649   unsigned int bitsize;
 650   machine_mode m;
 651   /* RID_* is RID_INTN_BASE + index into this array */
 652 };
 653
 654 /* This is also in tree.h.  genmodes.c guarantees the're sorted from
 655    smallest bitsize to largest bitsize. */
 656 extern bool int_n_enabled_p[NUM_INT_N_ENTS];
 657 extern const int_n_data_t int_n_data[NUM_INT_N_ENTS];
 658
 659 /* Return true if MODE has class MODE_FLOAT, storing it as a
 660    scalar_float_mode in *FLOAT_MODE if so.  */
 661
 662 template<typename T>
 663 inline bool
 664 is_float_mode (machine_mode mode, T *float_mode)
 665 {
 666   if (GET_MODE_CLASS (mode) == MODE_FLOAT)
 667     {
 668       *float_mode = scalar_float_mode (scalar_float_mode::from_int (mode));
 669       return true;
 670     }
 671   return false;
 672 }
 673
 674 namespace mode_iterator
 675 {
 676   /* Start mode iterator *ITER at the first mode in class MCLASS, if any.  */
 677
 678   template<typename T>
 679   inline void
 680   start (opt_mode<T> *iter, enum mode_class mclass)
 681   {
 682     if (GET_CLASS_NARROWEST_MODE (mclass) == E_VOIDmode)
 683       *iter = opt_mode<T> ();
 684     else
 685       *iter = as_a<T> (GET_CLASS_NARROWEST_MODE (mclass));
 686   }
 687
 688   inline void
 689   start (machine_mode *iter, enum mode_class mclass)
 690   {
 691     *iter = GET_CLASS_NARROWEST_MODE (mclass);
 692   }
 693
 694   /* Return true if mode iterator *ITER has not reached the end.  */
 695
 696   template<typename T>
 697   inline bool
 698   iterate_p (opt_mode<T> *iter)
 699   {
 700     return iter->exists ();
 701   }
 702
 703   inline bool
 704   iterate_p (machine_mode *iter)
 705   {
 706     return *iter != E_VOIDmode;
 707   }
 708
 709   /* Set mode iterator *ITER to the next widest mode in the same class,
 710      if any.  */
 711
 712   template<typename T>
 713   inline void
 714   get_wider (opt_mode<T> *iter)
 715   {
 716     *iter = GET_MODE_WIDER_MODE (iter->require ());
 717   }
 718
 719   inline void
 720   get_wider (machine_mode *iter)
 721   {
 722     *iter = GET_MODE_WIDER_MODE (*iter).else_void ();
 723   }
 724
 725   /* Set mode iterator *ITER to the next widest mode in the same class.
 726      Such a mode is known to exist.  */
 727
 728   template<typename T>
 729   inline void
 730   get_known_wider (T *iter)
 731   {
 732     *iter = GET_MODE_WIDER_MODE (*iter).require ();
 733   }
 734
 735   /* Set mode iterator *ITER to the mode that is two times wider than the
 736      current one, if such a mode exists.  */
 737
 738   inline void
 739   get_2xwider (machine_mode *iter)
 740   {
 741     *iter = GET_MODE_2XWIDER_MODE (*iter).else_void ();
 742   }
 743 }
 744
 745 /* Make ITERATOR iterate over all the modes in mode class CLASS,
 746    from narrowest to widest.  */
 747 #define FOR_EACH_MODE_IN_CLASS(ITERATOR, CLASS)  \
 748   for (mode_iterator::start (&(ITERATOR), CLASS); \
 749        mode_iterator::iterate_p (&(ITERATOR)); \
 750        mode_iterator::get_wider (&(ITERATOR)))
 751
 752 /* Make ITERATOR iterate over all the modes in the range [START, END),
 753    in order of increasing width.  */
 754 #define FOR_EACH_MODE(ITERATOR, START, END) \
 755   for ((ITERATOR) = (START); \
 756        (ITERATOR) != (END); \
 757        mode_iterator::get_known_wider (&(ITERATOR)))
 758
 759 /* Make ITERATOR iterate over START and all wider modes in the same
 760    class, in order of increasing width.  */
 761 #define FOR_EACH_MODE_FROM(ITERATOR, START) \
 762   for ((ITERATOR) = (START); \
 763        mode_iterator::iterate_p (&(ITERATOR)); \
 764        mode_iterator::get_wider (&(ITERATOR)))
 765
 766 /* Make ITERATOR iterate over modes in the range [NARROWEST, END)
 767    in order of increasing width, where NARROWEST is the narrowest mode
 768    in END's class.  */
 769 #define FOR_EACH_MODE_UNTIL(ITERATOR, END) \
 770   FOR_EACH_MODE (ITERATOR, get_narrowest_mode (END), END)
 771
 772 /* Make ITERATOR iterate over modes in the same class as MODE, in order
 773    of increasing width.  Start at the first mode wider than START,
 774    or don't iterate at all if there is no wider mode.  */
 775 #define FOR_EACH_WIDER_MODE(ITERATOR, START) \
 776   for ((ITERATOR) = (START), mode_iterator::get_wider (&(ITERATOR)); \
 777        mode_iterator::iterate_p (&(ITERATOR)); \
 778        mode_iterator::get_wider (&(ITERATOR)))
 779
 780 /* Make ITERATOR iterate over modes in the same class as MODE, in order
 781    of increasing width, and with each mode being twice the width of the
 782    previous mode.  Start at the mode that is two times wider than START,
 783    or don't iterate at all if there is no such mode.  */
 784 #define FOR_EACH_2XWIDER_MODE(ITERATOR, START) \
 785   for ((ITERATOR) = (START), mode_iterator::get_2xwider (&(ITERATOR)); \
 786        mode_iterator::iterate_p (&(ITERATOR)); \
 787        mode_iterator::get_2xwider (&(ITERATOR)))
 788
 789 #endif /* not HAVE_MACHINE_MODES */