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 /* A POD version of mode class T.  */
 297
 298 template<typename T>
 299 struct pod_mode
 300 {
 301   typedef typename mode_traits<T>::from_int from_int;
 302
 303   machine_mode m_mode;
 304   ALWAYS_INLINE operator machine_mode () const { return m_mode; }
 305   ALWAYS_INLINE operator T () const { return from_int (m_mode); }
 306   ALWAYS_INLINE pod_mode &operator = (const T &m) { m_mode = m; return *this; }
 307 };
 308
 309 /* Return true if mode M has type T.  */
 310
 311 template<typename T>
 312 inline bool
 313 is_a (machine_mode m)
 314 {
 315   return T::includes_p (m);
 316 }
 317
 318 /* Assert that mode M has type T, and return it in that form.  */
 319
 320 template<typename T>
 321 inline T
 322 as_a (machine_mode m)
 323 {
 324   gcc_checking_assert (T::includes_p (m));
 325   return typename mode_traits<T>::from_int (m);
 326 }
 327
 328 /* Convert M to an opt_mode<T>.  */
 329
 330 template<typename T>
 331 inline opt_mode<T>
 332 dyn_cast (machine_mode m)
 333 {
 334   if (T::includes_p (m))
 335     return T (typename mode_traits<T>::from_int (m));
 336   return opt_mode<T> ();
 337 }
 338
 339 /* Return true if mode M has type T, storing it as a T in *RESULT
 340    if so.  */
 341
 342 template<typename T, typename U>
 343 inline bool
 344 is_a (machine_mode m, U *result)
 345 {
 346   if (T::includes_p (m))
 347     {
 348       *result = T (typename mode_traits<T>::from_int (m));
 349       return true;
 350     }
 351   return false;
 352 }
 353
 354 /* Represents a machine mode that is known to be a SCALAR_INT_MODE_P.  */
 355 class scalar_int_mode
 356 {
 357 public:
 358   typedef mode_traits<scalar_int_mode>::from_int from_int;
 359
 360   ALWAYS_INLINE scalar_int_mode () {}
 361   ALWAYS_INLINE scalar_int_mode (from_int m) : m_mode (machine_mode (m)) {}
 362   ALWAYS_INLINE operator machine_mode () const { return m_mode; }
 363
 364   static bool includes_p (machine_mode);
 365
 366 protected:
 367   machine_mode m_mode;
 368 };
 369
 370 /* Return true if M is a scalar_int_mode.  */
 371
 372 inline bool
 373 scalar_int_mode::includes_p (machine_mode m)
 374 {
 375   return SCALAR_INT_MODE_P (m);
 376 }
 377
 378 /* Represents a machine mode that is known to be a SCALAR_FLOAT_MODE_P.  */
 379 class scalar_float_mode
 380 {
 381 public:
 382   typedef mode_traits<scalar_float_mode>::from_int from_int;
 383
 384   ALWAYS_INLINE scalar_float_mode () {}
 385   ALWAYS_INLINE scalar_float_mode (from_int m) : m_mode (machine_mode (m)) {}
 386   ALWAYS_INLINE operator machine_mode () const { return m_mode; }
 387
 388   static bool includes_p (machine_mode);
 389
 390 protected:
 391   machine_mode m_mode;
 392 };
 393
 394 /* Return true if M is a scalar_float_mode.  */
 395
 396 inline bool
 397 scalar_float_mode::includes_p (machine_mode m)
 398 {
 399   return SCALAR_FLOAT_MODE_P (m);
 400 }
 401
 402 /* Return the base GET_MODE_SIZE value for MODE.  */
 403
 404 ALWAYS_INLINE unsigned short
 405 mode_to_bytes (machine_mode mode)
 406 {
 407 #if GCC_VERSION >= 4001
 408   return (__builtin_constant_p (mode)
 409           ? mode_size_inline (mode) : mode_size[mode]);
 410 #else
 411   return mode_size[mode];
 412 #endif
 413 }
 414
 415 /* Return the base GET_MODE_BITSIZE value for MODE.  */
 416
 417 ALWAYS_INLINE unsigned short
 418 mode_to_bits (machine_mode mode)
 419 {
 420   return mode_to_bytes (mode) * BITS_PER_UNIT;
 421 }
 422
 423 /* Return the base GET_MODE_PRECISION value for MODE.  */
 424
 425 ALWAYS_INLINE unsigned short
 426 mode_to_precision (machine_mode mode)
 427 {
 428   return mode_precision[mode];
 429 }
 430
 431 /* Return the base GET_MODE_INNER value for MODE.  */
 432
 433 ALWAYS_INLINE machine_mode
 434 mode_to_inner (machine_mode mode)
 435 {
 436 #if GCC_VERSION >= 4001
 437   return (machine_mode) (__builtin_constant_p (mode)
 438                          ? mode_inner_inline (mode) : mode_inner[mode]);
 439 #else
 440   return (machine_mode) mode_inner[mode];
 441 #endif
 442 }
 443
 444 /* Return the base GET_MODE_UNIT_SIZE value for MODE.  */
 445
 446 ALWAYS_INLINE unsigned char
 447 mode_to_unit_size (machine_mode mode)
 448 {
 449 #if GCC_VERSION >= 4001
 450   return (__builtin_constant_p (mode)
 451           ? mode_unit_size_inline (mode) : mode_unit_size[mode]);
 452 #else
 453   return mode_unit_size[mode];
 454 #endif
 455 }
 456
 457 /* Return the base GET_MODE_UNIT_PRECISION value for MODE.  */
 458
 459 ALWAYS_INLINE unsigned short
 460 mode_to_unit_precision (machine_mode mode)
 461 {
 462 #if GCC_VERSION >= 4001
 463   return (__builtin_constant_p (mode)
 464           ? mode_unit_precision_inline (mode) : mode_unit_precision[mode]);
 465 #else
 466   return mode_unit_precision[mode];
 467 #endif
 468 }
 469
 470 /* Return the base GET_MODE_NUNITS value for MODE.  */
 471
 472 ALWAYS_INLINE unsigned short
 473 mode_to_nunits (machine_mode mode)
 474 {
 475 #if GCC_VERSION >= 4001
 476   return (__builtin_constant_p (mode)
 477           ? mode_nunits_inline (mode) : mode_nunits[mode]);
 478 #else
 479   return mode_nunits[mode];
 480 #endif
 481 }
 482
 483 /* Get the size in bytes of an object of mode MODE.  */
 484
 485 #define GET_MODE_SIZE(MODE) (mode_to_bytes (MODE))
 486
 487 /* Get the size in bits of an object of mode MODE.  */
 488
 489 #define GET_MODE_BITSIZE(MODE) (mode_to_bits (MODE))
 490
 491 /* Get the number of value bits of an object of mode MODE.  */
 492
 493 #define GET_MODE_PRECISION(MODE) (mode_to_precision (MODE))
 494
 495 /* Get the number of integral bits of an object of mode MODE.  */
 496 extern CONST_MODE_IBIT unsigned char mode_ibit[NUM_MACHINE_MODES];
 497 #define GET_MODE_IBIT(MODE) mode_ibit[MODE]
 498
 499 /* Get the number of fractional bits of an object of mode MODE.  */
 500 extern CONST_MODE_FBIT unsigned char mode_fbit[NUM_MACHINE_MODES];
 501 #define GET_MODE_FBIT(MODE) mode_fbit[MODE]
 502
 503 /* Get a bitmask containing 1 for all bits in a word
 504    that fit within mode MODE.  */
 505
 506 extern const unsigned HOST_WIDE_INT mode_mask_array[NUM_MACHINE_MODES];
 507
 508 #define GET_MODE_MASK(MODE) mode_mask_array[MODE]
 509
 510 /* Return the mode of the basic parts of MODE.  For vector modes this is the
 511    mode of the vector elements.  For complex modes it is the mode of the real
 512    and imaginary parts.  For other modes it is MODE itself.  */
 513
 514 #define GET_MODE_INNER(MODE) (mode_to_inner (MODE))
 515
 516 /* Get the size in bytes or bits of the basic parts of an
 517    object of mode MODE.  */
 518
 519 #define GET_MODE_UNIT_SIZE(MODE) mode_to_unit_size (MODE)
 520
 521 #define GET_MODE_UNIT_BITSIZE(MODE) \
 522   ((unsigned short) (GET_MODE_UNIT_SIZE (MODE) * BITS_PER_UNIT))
 523
 524 #define GET_MODE_UNIT_PRECISION(MODE) (mode_to_unit_precision (MODE))
 525
 526 /* Get the number of units in an object of mode MODE.  This is 2 for
 527    complex modes and the number of elements for vector modes.  */
 528
 529 #define GET_MODE_NUNITS(MODE) (mode_to_nunits (MODE))
 530
 531 /* Get the next wider natural mode (eg, QI -> HI -> SI -> DI -> TI).  */
 532
 533 template<typename T>
 534 ALWAYS_INLINE opt_mode<T>
 535 GET_MODE_WIDER_MODE (const T &m)
 536 {
 537   return typename opt_mode<T>::from_int (mode_wider[m]);
 538 }
 539
 540 /* For scalars, this is a mode with twice the precision.  For vectors,
 541    this is a mode with the same inner mode but with twice the elements.  */
 542
 543 template<typename T>
 544 ALWAYS_INLINE opt_mode<T>
 545 GET_MODE_2XWIDER_MODE (const T &m)
 546 {
 547   return typename opt_mode<T>::from_int (mode_2xwider[m]);
 548 }
 549
 550 /* Get the complex mode from the component mode.  */
 551 extern const unsigned char mode_complex[NUM_MACHINE_MODES];
 552 #define GET_MODE_COMPLEX_MODE(MODE) ((machine_mode) mode_complex[MODE])
 553
 554 /* Return the mode for data of a given size SIZE and mode class CLASS.
 555    If LIMIT is nonzero, then don't use modes bigger than MAX_FIXED_MODE_SIZE.
 556    The value is BLKmode if no other mode is found.  */
 557
 558 extern machine_mode mode_for_size (unsigned int, enum mode_class, int);
 559
 560 /* Return the machine mode to use for a MODE_INT of SIZE bits, if one
 561    exists.  If LIMIT is nonzero, modes wider than MAX_FIXED_MODE_SIZE
 562    will not be used.  */
 563
 564 inline opt_scalar_int_mode
 565 int_mode_for_size (unsigned int size, int limit)
 566 {
 567   return dyn_cast <scalar_int_mode> (mode_for_size (size, MODE_INT, limit));
 568 }
 569
 570 /* Return the machine mode to use for a MODE_FLOAT of SIZE bits, if one
 571    exists.  */
 572
 573 inline opt_scalar_float_mode
 574 float_mode_for_size (unsigned int size)
 575 {
 576   return dyn_cast <scalar_float_mode> (mode_for_size (size, MODE_FLOAT, 0));
 577 }
 578
 579 /* Similar to mode_for_size, but find the smallest mode for a given width.  */
 580
 581 extern machine_mode smallest_mode_for_size (unsigned int,
 582                                                  enum mode_class);
 583
 584
 585 /* Return an integer mode of the exact same size as the input mode,
 586    or BLKmode on failure.  */
 587
 588 extern machine_mode int_mode_for_mode (machine_mode);
 589
 590 extern machine_mode bitwise_mode_for_mode (machine_mode);
 591
 592 /* Return a mode that is suitable for representing a vector,
 593    or BLKmode on failure.  */
 594
 595 extern machine_mode mode_for_vector (machine_mode, unsigned);
 596
 597 /* A class for iterating through possible bitfield modes.  */
 598 class bit_field_mode_iterator
 599 {
 600 public:
 601   bit_field_mode_iterator (HOST_WIDE_INT, HOST_WIDE_INT,
 602                            HOST_WIDE_INT, HOST_WIDE_INT,
 603                            unsigned int, bool);
 604   bool next_mode (machine_mode *);
 605   bool prefer_smaller_modes ();
 606
 607 private:
 608   machine_mode m_mode;
 609   /* We use signed values here because the bit position can be negative
 610      for invalid input such as gcc.dg/pr48335-8.c.  */
 611   HOST_WIDE_INT m_bitsize;
 612   HOST_WIDE_INT m_bitpos;
 613   HOST_WIDE_INT m_bitregion_start;
 614   HOST_WIDE_INT m_bitregion_end;
 615   unsigned int m_align;
 616   bool m_volatilep;
 617   int m_count;
 618 };
 619
 620 /* Find the best mode to use to access a bit field.  */
 621
 622 extern machine_mode get_best_mode (int, int,
 623                                         unsigned HOST_WIDE_INT,
 624                                         unsigned HOST_WIDE_INT,
 625                                         unsigned int,
 626                                         machine_mode, bool);
 627
 628 /* Determine alignment, 1<=result<=BIGGEST_ALIGNMENT.  */
 629
 630 extern CONST_MODE_BASE_ALIGN unsigned short mode_base_align[NUM_MACHINE_MODES];
 631
 632 extern unsigned get_mode_alignment (machine_mode);
 633
 634 #define GET_MODE_ALIGNMENT(MODE) get_mode_alignment (MODE)
 635
 636 /* For each class, get the narrowest mode in that class.  */
 637
 638 extern const unsigned char class_narrowest_mode[MAX_MODE_CLASS];
 639 #define GET_CLASS_NARROWEST_MODE(CLASS) \
 640   ((machine_mode) class_narrowest_mode[CLASS])
 641
 642 /* Return the narrowest mode in T's class.  */
 643
 644 template<typename T>
 645 inline T
 646 get_narrowest_mode (T mode)
 647 {
 648   return typename mode_traits<T>::from_int
 649     (class_narrowest_mode[GET_MODE_CLASS (mode)]);
 650 }
 651
 652 /* Define the integer modes whose sizes are BITS_PER_UNIT and BITS_PER_WORD
 653    and the mode whose class is Pmode and whose size is POINTER_SIZE.  */
 654
 655 extern scalar_int_mode byte_mode;
 656 extern scalar_int_mode word_mode;
 657 extern scalar_int_mode ptr_mode;
 658
 659 /* Target-dependent machine mode initialization - in insn-modes.c.  */
 660 extern void init_adjust_machine_modes (void);
 661
 662 #define TRULY_NOOP_TRUNCATION_MODES_P(MODE1, MODE2) \
 663   TRULY_NOOP_TRUNCATION (GET_MODE_PRECISION (MODE1), \
 664                          GET_MODE_PRECISION (MODE2))
 665
 666 #define HWI_COMPUTABLE_MODE_P(MODE) \
 667   (SCALAR_INT_MODE_P (MODE) \
 668    && GET_MODE_PRECISION (MODE) <= HOST_BITS_PER_WIDE_INT)
 669
 670 struct int_n_data_t {
 671   /* These parts are initailized by genmodes output */
 672   unsigned int bitsize;
 673   scalar_int_mode_pod m;
 674   /* RID_* is RID_INTN_BASE + index into this array */
 675 };
 676
 677 /* This is also in tree.h.  genmodes.c guarantees the're sorted from
 678    smallest bitsize to largest bitsize. */
 679 extern bool int_n_enabled_p[NUM_INT_N_ENTS];
 680 extern const int_n_data_t int_n_data[NUM_INT_N_ENTS];
 681
 682 /* Return true if MODE has class MODE_FLOAT, storing it as a
 683    scalar_float_mode in *FLOAT_MODE if so.  */
 684
 685 template<typename T>
 686 inline bool
 687 is_float_mode (machine_mode mode, T *float_mode)
 688 {
 689   if (GET_MODE_CLASS (mode) == MODE_FLOAT)
 690     {
 691       *float_mode = scalar_float_mode (scalar_float_mode::from_int (mode));
 692       return true;
 693     }
 694   return false;
 695 }
 696
 697 namespace mode_iterator
 698 {
 699   /* Start mode iterator *ITER at the first mode in class MCLASS, if any.  */
 700
 701   template<typename T>
 702   inline void
 703   start (opt_mode<T> *iter, enum mode_class mclass)
 704   {
 705     if (GET_CLASS_NARROWEST_MODE (mclass) == E_VOIDmode)
 706       *iter = opt_mode<T> ();
 707     else
 708       *iter = as_a<T> (GET_CLASS_NARROWEST_MODE (mclass));
 709   }
 710
 711   inline void
 712   start (machine_mode *iter, enum mode_class mclass)
 713   {
 714     *iter = GET_CLASS_NARROWEST_MODE (mclass);
 715   }
 716
 717   /* Return true if mode iterator *ITER has not reached the end.  */
 718
 719   template<typename T>
 720   inline bool
 721   iterate_p (opt_mode<T> *iter)
 722   {
 723     return iter->exists ();
 724   }
 725
 726   inline bool
 727   iterate_p (machine_mode *iter)
 728   {
 729     return *iter != E_VOIDmode;
 730   }
 731
 732   /* Set mode iterator *ITER to the next widest mode in the same class,
 733      if any.  */
 734
 735   template<typename T>
 736   inline void
 737   get_wider (opt_mode<T> *iter)
 738   {
 739     *iter = GET_MODE_WIDER_MODE (iter->require ());
 740   }
 741
 742   inline void
 743   get_wider (machine_mode *iter)
 744   {
 745     *iter = GET_MODE_WIDER_MODE (*iter).else_void ();
 746   }
 747
 748   /* Set mode iterator *ITER to the next widest mode in the same class.
 749      Such a mode is known to exist.  */
 750
 751   template<typename T>
 752   inline void
 753   get_known_wider (T *iter)
 754   {
 755     *iter = GET_MODE_WIDER_MODE (*iter).require ();
 756   }
 757
 758   /* Set mode iterator *ITER to the mode that is two times wider than the
 759      current one, if such a mode exists.  */
 760
 761   inline void
 762   get_2xwider (machine_mode *iter)
 763   {
 764     *iter = GET_MODE_2XWIDER_MODE (*iter).else_void ();
 765   }
 766 }
 767
 768 /* Make ITERATOR iterate over all the modes in mode class CLASS,
 769    from narrowest to widest.  */
 770 #define FOR_EACH_MODE_IN_CLASS(ITERATOR, CLASS)  \
 771   for (mode_iterator::start (&(ITERATOR), CLASS); \
 772        mode_iterator::iterate_p (&(ITERATOR)); \
 773        mode_iterator::get_wider (&(ITERATOR)))
 774
 775 /* Make ITERATOR iterate over all the modes in the range [START, END),
 776    in order of increasing width.  */
 777 #define FOR_EACH_MODE(ITERATOR, START, END) \
 778   for ((ITERATOR) = (START); \
 779        (ITERATOR) != (END); \
 780        mode_iterator::get_known_wider (&(ITERATOR)))
 781
 782 /* Make ITERATOR iterate over START and all wider modes in the same
 783    class, in order of increasing width.  */
 784 #define FOR_EACH_MODE_FROM(ITERATOR, START) \
 785   for ((ITERATOR) = (START); \
 786        mode_iterator::iterate_p (&(ITERATOR)); \
 787        mode_iterator::get_wider (&(ITERATOR)))
 788
 789 /* Make ITERATOR iterate over modes in the range [NARROWEST, END)
 790    in order of increasing width, where NARROWEST is the narrowest mode
 791    in END's class.  */
 792 #define FOR_EACH_MODE_UNTIL(ITERATOR, END) \
 793   FOR_EACH_MODE (ITERATOR, get_narrowest_mode (END), END)
 794
 795 /* Make ITERATOR iterate over modes in the same class as MODE, in order
 796    of increasing width.  Start at the first mode wider than START,
 797    or don't iterate at all if there is no wider mode.  */
 798 #define FOR_EACH_WIDER_MODE(ITERATOR, START) \
 799   for ((ITERATOR) = (START), mode_iterator::get_wider (&(ITERATOR)); \
 800        mode_iterator::iterate_p (&(ITERATOR)); \
 801        mode_iterator::get_wider (&(ITERATOR)))
 802
 803 /* Make ITERATOR iterate over modes in the same class as MODE, in order
 804    of increasing width, and with each mode being twice the width of the
 805    previous mode.  Start at the mode that is two times wider than START,
 806    or don't iterate at all if there is no such mode.  */
 807 #define FOR_EACH_2XWIDER_MODE(ITERATOR, START) \
 808   for ((ITERATOR) = (START), mode_iterator::get_2xwider (&(ITERATOR)); \
 809        mode_iterator::iterate_p (&(ITERATOR)); \
 810        mode_iterator::get_2xwider (&(ITERATOR)))
 811
 812 #endif /* not HAVE_MACHINE_MODES */