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- /* Definitions of floating-point access for GNU compiler.
- Copyright (C) 1989-2020 Free Software Foundation, Inc.
-
- This file is part of GCC.
-
- GCC is free software; you can redistribute it and/or modify it under
- the terms of the GNU General Public License as published by the Free
- Software Foundation; either version 3, or (at your option) any later
- version.
-
- GCC is distributed in the hope that it will be useful, but WITHOUT ANY
- WARRANTY; without even the implied warranty of MERCHANTABILITY or
- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- for more details.
-
- You should have received a copy of the GNU General Public License
- along with GCC; see the file COPYING3. If not see
- <http://www.gnu.org/licenses/>. */
-
- #ifndef GCC_REAL_H
- #define GCC_REAL_H
-
- /* An expanded form of the represented number. */
-
- /* Enumerate the special cases of numbers that we encounter. */
- enum real_value_class {
- rvc_zero,
- rvc_normal,
- rvc_inf,
- rvc_nan
- };
-
- #define SIGNIFICAND_BITS (128 + HOST_BITS_PER_LONG)
- #define EXP_BITS (32 - 6)
- #define MAX_EXP ((1 << (EXP_BITS - 1)) - 1)
- #define SIGSZ (SIGNIFICAND_BITS / HOST_BITS_PER_LONG)
- #define SIG_MSB ((unsigned long)1 << (HOST_BITS_PER_LONG - 1))
-
- struct GTY(()) real_value {
- /* Use the same underlying type for all bit-fields, so as to make
- sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will
- be miscomputed. */
- unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2;
- /* 1 if number is decimal floating point. */
- unsigned int decimal : 1;
- /* 1 if number is negative. */
- unsigned int sign : 1;
- /* 1 if number is signalling. */
- unsigned int signalling : 1;
- /* 1 if number is canonical
- All are generally used for handling cases in real.c. */
- unsigned int canonical : 1;
- /* unbiased exponent of the number. */
- unsigned int uexp : EXP_BITS;
- /* significand of the number. */
- unsigned long sig[SIGSZ];
- };
-
- #define REAL_EXP(REAL) \
- ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \
- - (1 << (EXP_BITS - 1)))
- #define SET_REAL_EXP(REAL, EXP) \
- ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1)))
-
- /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it
- needs to be a macro. We do need to continue to have a structure tag
- so that other headers can forward declare it. */
- #define REAL_VALUE_TYPE struct real_value
-
- /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in
- consecutive "w" slots. Moreover, we've got to compute the number of "w"
- slots at preprocessor time, which means we can't use sizeof. Guess. */
-
- #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32)
- #define REAL_WIDTH \
- (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
- + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
-
- /* Verify the guess. */
- extern char test_real_width
- [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
-
- /* Calculate the format for CONST_DOUBLE. We need as many slots as
- are necessary to overlay a REAL_VALUE_TYPE on them. This could be
- as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).
-
- A number of places assume that there are always at least two 'w'
- slots in a CONST_DOUBLE, so we provide them even if one would suffice. */
-
- #if REAL_WIDTH == 1
- # define CONST_DOUBLE_FORMAT "ww"
- #else
- # if REAL_WIDTH == 2
- # define CONST_DOUBLE_FORMAT "ww"
- # else
- # if REAL_WIDTH == 3
- # define CONST_DOUBLE_FORMAT "www"
- # else
- # if REAL_WIDTH == 4
- # define CONST_DOUBLE_FORMAT "wwww"
- # else
- # if REAL_WIDTH == 5
- # define CONST_DOUBLE_FORMAT "wwwww"
- # else
- # if REAL_WIDTH == 6
- # define CONST_DOUBLE_FORMAT "wwwwww"
- # else
- #error "REAL_WIDTH > 6 not supported"
- # endif
- # endif
- # endif
- # endif
- # endif
- #endif
-
-
- /* Describes the properties of the specific target format in use. */
- struct real_format
- {
- /* Move to and from the target bytes. */
- void (*encode) (const struct real_format *, long *,
- const REAL_VALUE_TYPE *);
- void (*decode) (const struct real_format *, REAL_VALUE_TYPE *,
- const long *);
-
- /* The radix of the exponent and digits of the significand. */
- int b;
-
- /* Size of the significand in digits of radix B. */
- int p;
-
- /* Size of the significant of a NaN, in digits of radix B. */
- int pnan;
-
- /* The minimum negative integer, x, such that b**(x-1) is normalized. */
- int emin;
-
- /* The maximum integer, x, such that b**(x-1) is representable. */
- int emax;
-
- /* The bit position of the sign bit, for determining whether a value
- is positive/negative, or -1 for a complex encoding. */
- int signbit_ro;
-
- /* The bit position of the sign bit, for changing the sign of a number,
- or -1 for a complex encoding. */
- int signbit_rw;
-
- /* If this is an IEEE interchange format, the number of bits in the
- format; otherwise, if it is an IEEE extended format, one more
- than the greatest number of bits in an interchange format it
- extends; otherwise 0. Formats need not follow the IEEE 754-2008
- recommended practice regarding how signaling NaNs are identified,
- and may vary in the choice of default NaN, but must follow other
- IEEE practice regarding having NaNs, infinities and subnormal
- values, and the relation of minimum and maximum exponents, and,
- for interchange formats, the details of the encoding. */
- int ieee_bits;
-
- /* Default rounding mode for operations on this format. */
- bool round_towards_zero;
- bool has_sign_dependent_rounding;
-
- /* Properties of the format. */
- bool has_nans;
- bool has_inf;
- bool has_denorm;
- bool has_signed_zero;
- bool qnan_msb_set;
- bool canonical_nan_lsbs_set;
- const char *name;
- };
-
-
- /* The target format used for each floating point mode.
- Float modes are followed by decimal float modes, with entries for
- float modes indexed by (MODE - first float mode), and entries for
- decimal float modes indexed by (MODE - first decimal float mode) +
- the number of float modes. */
- extern const struct real_format *
- real_format_for_mode[MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1
- + MAX_MODE_DECIMAL_FLOAT - MIN_MODE_DECIMAL_FLOAT + 1];
-
- #define REAL_MODE_FORMAT(MODE) \
- (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE) \
- ? (((MODE) - MIN_MODE_DECIMAL_FLOAT) \
- + (MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1)) \
- : GET_MODE_CLASS (MODE) == MODE_FLOAT \
- ? ((MODE) - MIN_MODE_FLOAT) \
- : (gcc_unreachable (), 0)])
-
- #define FLOAT_MODE_FORMAT(MODE) \
- (REAL_MODE_FORMAT (as_a <scalar_float_mode> (GET_MODE_INNER (MODE))))
-
- /* The following macro determines whether the floating point format is
- composite, i.e. may contain non-consecutive mantissa bits, in which
- case compile-time FP overflow may not model run-time overflow. */
- #define MODE_COMPOSITE_P(MODE) \
- (FLOAT_MODE_P (MODE) \
- && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p)
-
- /* Accessor macros for format properties. */
- #define MODE_HAS_NANS(MODE) \
- (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans)
- #define MODE_HAS_INFINITIES(MODE) \
- (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf)
- #define MODE_HAS_SIGNED_ZEROS(MODE) \
- (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero)
- #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \
- (FLOAT_MODE_P (MODE) \
- && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding)
-
- /* This class allows functions in this file to accept a floating-point
- format as either a mode or an explicit real_format pointer. In the
- former case the mode must be VOIDmode (which means "no particular
- format") or must satisfy SCALAR_FLOAT_MODE_P. */
- class format_helper
- {
- public:
- format_helper (const real_format *format) : m_format (format) {}
- template<typename T> format_helper (const T &);
- const real_format *operator-> () const { return m_format; }
- operator const real_format *() const { return m_format; }
-
- bool decimal_p () const { return m_format && m_format->b == 10; }
- bool can_represent_integral_type_p (tree type) const;
-
- private:
- const real_format *m_format;
- };
-
- template<typename T>
- inline format_helper::format_helper (const T &m)
- : m_format (m == VOIDmode ? 0 : REAL_MODE_FORMAT (m))
- {}
-
- /* Declare functions in real.c. */
-
- /* True if the given mode has a NaN representation and the treatment of
- NaN operands is important. Certain optimizations, such as folding
- x * 0 into 0, are not correct for NaN operands, and are normally
- disabled for modes with NaNs. The user can ask for them to be
- done anyway using the -funsafe-math-optimizations switch. */
- extern bool HONOR_NANS (machine_mode);
- extern bool HONOR_NANS (const_tree);
- extern bool HONOR_NANS (const_rtx);
-
- /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs). */
- extern bool HONOR_SNANS (machine_mode);
- extern bool HONOR_SNANS (const_tree);
- extern bool HONOR_SNANS (const_rtx);
-
- /* As for HONOR_NANS, but true if the mode can represent infinity and
- the treatment of infinite values is important. */
- extern bool HONOR_INFINITIES (machine_mode);
- extern bool HONOR_INFINITIES (const_tree);
- extern bool HONOR_INFINITIES (const_rtx);
-
- /* Like HONOR_NANS, but true if the given mode distinguishes between
- positive and negative zero, and the sign of zero is important. */
- extern bool HONOR_SIGNED_ZEROS (machine_mode);
- extern bool HONOR_SIGNED_ZEROS (const_tree);
- extern bool HONOR_SIGNED_ZEROS (const_rtx);
-
- /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
- and the rounding mode is important. */
- extern bool HONOR_SIGN_DEPENDENT_ROUNDING (machine_mode);
- extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_tree);
- extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_rtx);
-
- /* Binary or unary arithmetic on tree_code. */
- extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *,
- const REAL_VALUE_TYPE *);
-
- /* Compare reals by tree_code. */
- extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
-
- /* Determine whether a floating-point value X is infinite. */
- extern bool real_isinf (const REAL_VALUE_TYPE *);
-
- /* Determine whether a floating-point value X is a NaN. */
- extern bool real_isnan (const REAL_VALUE_TYPE *);
-
- /* Determine whether a floating-point value X is a signaling NaN. */
- extern bool real_issignaling_nan (const REAL_VALUE_TYPE *);
-
- /* Determine whether a floating-point value X is finite. */
- extern bool real_isfinite (const REAL_VALUE_TYPE *);
-
- /* Determine whether a floating-point value X is negative. */
- extern bool real_isneg (const REAL_VALUE_TYPE *);
-
- /* Determine whether a floating-point value X is minus zero. */
- extern bool real_isnegzero (const REAL_VALUE_TYPE *);
-
- /* Test relationships between reals. */
- extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
- extern bool real_equal (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
- extern bool real_less (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
-
- /* Extend or truncate to a new format. */
- extern void real_convert (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *);
-
- /* Return true if truncating to NEW is exact. */
- extern bool exact_real_truncate (format_helper, const REAL_VALUE_TYPE *);
-
- /* Render R as a decimal floating point constant. */
- extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t,
- size_t, int);
-
- /* Render R as a decimal floating point constant, rounded so as to be
- parsed back to the same value when interpreted in mode MODE. */
- extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t,
- size_t, int, machine_mode);
-
- /* Render R as a hexadecimal floating point constant. */
- extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *,
- size_t, size_t, int);
-
- /* Render R as an integer. */
- extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *);
-
- /* Initialize R from a decimal or hexadecimal string. Return -1 if
- the value underflows, +1 if overflows, and 0 otherwise. */
- extern int real_from_string (REAL_VALUE_TYPE *, const char *);
- /* Wrapper to allow different internal representation for decimal floats. */
- extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, format_helper);
-
- extern long real_to_target (long *, const REAL_VALUE_TYPE *, format_helper);
-
- extern void real_from_target (REAL_VALUE_TYPE *, const long *,
- format_helper);
-
- extern void real_inf (REAL_VALUE_TYPE *);
-
- extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, format_helper);
-
- extern void real_maxval (REAL_VALUE_TYPE *, int, machine_mode);
-
- extern void real_2expN (REAL_VALUE_TYPE *, int, format_helper);
-
- extern unsigned int real_hash (const REAL_VALUE_TYPE *);
-
-
- /* Target formats defined in real.c. */
- extern const struct real_format ieee_single_format;
- extern const struct real_format mips_single_format;
- extern const struct real_format motorola_single_format;
- extern const struct real_format spu_single_format;
- extern const struct real_format ieee_double_format;
- extern const struct real_format mips_double_format;
- extern const struct real_format motorola_double_format;
- extern const struct real_format ieee_extended_motorola_format;
- extern const struct real_format ieee_extended_intel_96_format;
- extern const struct real_format ieee_extended_intel_96_round_53_format;
- extern const struct real_format ieee_extended_intel_128_format;
- extern const struct real_format ibm_extended_format;
- extern const struct real_format mips_extended_format;
- extern const struct real_format ieee_quad_format;
- extern const struct real_format mips_quad_format;
- extern const struct real_format vax_f_format;
- extern const struct real_format vax_d_format;
- extern const struct real_format vax_g_format;
- extern const struct real_format real_internal_format;
- extern const struct real_format decimal_single_format;
- extern const struct real_format decimal_double_format;
- extern const struct real_format decimal_quad_format;
- extern const struct real_format ieee_half_format;
- extern const struct real_format arm_half_format;
- extern const struct real_format arm_bfloat_half_format;
-
-
- /* ====================================================================== */
- /* Crap. */
-
- /* Determine whether a floating-point value X is infinite. */
- #define REAL_VALUE_ISINF(x) real_isinf (&(x))
-
- /* Determine whether a floating-point value X is a NaN. */
- #define REAL_VALUE_ISNAN(x) real_isnan (&(x))
-
- /* Determine whether a floating-point value X is a signaling NaN. */
- #define REAL_VALUE_ISSIGNALING_NAN(x) real_issignaling_nan (&(x))
-
- /* Determine whether a floating-point value X is negative. */
- #define REAL_VALUE_NEGATIVE(x) real_isneg (&(x))
-
- /* Determine whether a floating-point value X is minus zero. */
- #define REAL_VALUE_MINUS_ZERO(x) real_isnegzero (&(x))
-
- /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */
- #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) \
- real_to_target (OUT, &(IN), \
- float_mode_for_size (LONG_DOUBLE_TYPE_SIZE).require ())
-
- #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
- real_to_target (OUT, &(IN), float_mode_for_size (64).require ())
-
- /* IN is a REAL_VALUE_TYPE. OUT is a long. */
- #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
- ((OUT) = real_to_target (NULL, &(IN), float_mode_for_size (32).require ()))
-
- /* Real values to IEEE 754 decimal floats. */
-
- /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */
- #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \
- real_to_target (OUT, &(IN), decimal_float_mode_for_size (128).require ())
-
- #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
- real_to_target (OUT, &(IN), decimal_float_mode_for_size (64).require ())
-
- /* IN is a REAL_VALUE_TYPE. OUT is a long. */
- #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \
- ((OUT) = real_to_target (NULL, &(IN), \
- decimal_float_mode_for_size (32).require ()))
-
- extern REAL_VALUE_TYPE real_value_truncate (format_helper, REAL_VALUE_TYPE);
-
- extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *);
- extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *);
-
- extern int significand_size (format_helper);
-
- extern REAL_VALUE_TYPE real_from_string2 (const char *, format_helper);
-
- #define REAL_VALUE_ATOF(s, m) \
- real_from_string2 (s, m)
-
- #define CONST_DOUBLE_ATOF(s, m) \
- const_double_from_real_value (real_from_string2 (s, m), m)
-
- #define REAL_VALUE_FIX(r) \
- real_to_integer (&(r))
-
- /* ??? Not quite right. */
- #define REAL_VALUE_UNSIGNED_FIX(r) \
- real_to_integer (&(r))
-
- /* ??? These were added for Paranoia support. */
-
- /* Return floor log2(R). */
- extern int real_exponent (const REAL_VALUE_TYPE *);
-
- /* R = A * 2**EXP. */
- extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
-
- /* **** End of software floating point emulator interface macros **** */
-
- /* Constant real values 0, 1, 2, -1 and 0.5. */
-
- extern REAL_VALUE_TYPE dconst0;
- extern REAL_VALUE_TYPE dconst1;
- extern REAL_VALUE_TYPE dconst2;
- extern REAL_VALUE_TYPE dconstm1;
- extern REAL_VALUE_TYPE dconsthalf;
-
- #define dconst_e() (*dconst_e_ptr ())
- #define dconst_third() (*dconst_third_ptr ())
- #define dconst_quarter() (*dconst_quarter_ptr ())
- #define dconst_sixth() (*dconst_sixth_ptr ())
- #define dconst_ninth() (*dconst_ninth_ptr ())
- #define dconst_sqrt2() (*dconst_sqrt2_ptr ())
-
- /* Function to return the real value special constant 'e'. */
- extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
-
- /* Returns a cached REAL_VALUE_TYPE corresponding to 1/n, for various n. */
- extern const REAL_VALUE_TYPE *dconst_third_ptr (void);
- extern const REAL_VALUE_TYPE *dconst_quarter_ptr (void);
- extern const REAL_VALUE_TYPE *dconst_sixth_ptr (void);
- extern const REAL_VALUE_TYPE *dconst_ninth_ptr (void);
-
- /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2). */
- extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
-
- /* Function to return a real value (not a tree node)
- from a given integer constant. */
- REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree);
-
- /* Return a CONST_DOUBLE with value R and mode M. */
- extern rtx const_double_from_real_value (REAL_VALUE_TYPE, machine_mode);
-
- /* Replace R by 1/R in the given format, if the result is exact. */
- extern bool exact_real_inverse (format_helper, REAL_VALUE_TYPE *);
-
- /* Return true if arithmetic on values in IMODE that were promoted
- from values in TMODE is equivalent to direct arithmetic on values
- in TMODE. */
- bool real_can_shorten_arithmetic (machine_mode, machine_mode);
-
- /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node. */
- extern tree build_real (tree, REAL_VALUE_TYPE);
-
- /* Likewise, but first truncate the value to the type. */
- extern tree build_real_truncate (tree, REAL_VALUE_TYPE);
-
- /* Calculate R as X raised to the integer exponent N in format FMT. */
- extern bool real_powi (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *, HOST_WIDE_INT);
-
- /* Standard round to integer value functions. */
- extern void real_trunc (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *);
- extern void real_floor (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *);
- extern void real_ceil (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *);
- extern void real_round (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *);
- extern void real_roundeven (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *);
-
- /* Set the sign of R to the sign of X. */
- extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
-
- /* Check whether the real constant value given is an integer. */
- extern bool real_isinteger (const REAL_VALUE_TYPE *, format_helper);
- extern bool real_isinteger (const REAL_VALUE_TYPE *, HOST_WIDE_INT *);
-
- /* Calculate nextafter (X, Y) in format FMT. */
- extern bool real_nextafter (REAL_VALUE_TYPE *, format_helper,
- const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
-
- /* Write into BUF the maximum representable finite floating-point
- number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
- float string. BUF must be large enough to contain the result. */
- extern void get_max_float (const struct real_format *, char *, size_t, bool);
-
- #ifndef GENERATOR_FILE
- /* real related routines. */
- extern wide_int real_to_integer (const REAL_VALUE_TYPE *, bool *, int);
- extern void real_from_integer (REAL_VALUE_TYPE *, format_helper,
- const wide_int_ref &, signop);
- #endif
-
- /* Fills r with the largest value such that 1 + r*r won't overflow.
- This is used in both sin (atan (x)) and cos (atan(x)) optimizations. */
- extern void build_sinatan_real (REAL_VALUE_TYPE *, tree);
-
- #endif /* ! GCC_REAL_H */
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