/* Floating point routines for GDB, the GNU debugger.
- Copyright (C) 2017 Free Software Foundation, Inc.
+ Copyright (C) 2017-2019 Free Software Foundation, Inc.
This file is part of GDB.
#include "gdbtypes.h"
#include "floatformat.h"
#include "target-float.h"
-
+#include "gdbarch.h"
/* Target floating-point operations.
}
unsigned char *ufrom = (unsigned char *) from;
- T dto;
long exponent;
unsigned long mant;
unsigned int mant_bits, mant_off;
{
double dto;
- floatformat_to_double (fmt->split_half ? fmt->split_half : fmt,
- from, &dto);
+ floatformat_to_double /* ARI: floatformat_to_double */
+ (fmt->split_half ? fmt->split_half : fmt, from, &dto);
*to = (T) dto;
return;
}
mant_bits_left = fmt->man_len;
mant_off = fmt->man_start;
- dto = 0.0;
+ T dto = 0.0;
special_exponent = exponent == 0 || exponent == fmt->exp_nan;
T host_float;
from_target (type, addr, &host_float);
+
+ DIAGNOSTIC_PUSH
+ DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
return string_printf (host_format.c_str (), host_float);
+ DIAGNOSTIC_POP
}
/* Parse string IN into a target floating-number of type TYPE and
scan_format += scanf_length_modifier<T>::value;
scan_format += "g%n";
+ DIAGNOSTIC_PUSH
+ DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
num = sscanf (in.c_str (), scan_format.c_str(), &host_float, &n);
+ DIAGNOSTIC_POP
/* The sscanf man page suggests not making any assumptions on the effect
of %n on the result, so we don't.
{
T host_float;
from_target (type, addr, &host_float);
- /* Converting an out-of-range value is undefined behavior in C, but we
- prefer to return a defined value here. */
- if (host_float > std::numeric_limits<LONGEST>::max())
- return std::numeric_limits<LONGEST>::max();
- if (host_float < std::numeric_limits<LONGEST>::min())
+ T min_possible_range = static_cast<T>(std::numeric_limits<LONGEST>::min());
+ T max_possible_range = -min_possible_range;
+ /* host_float can be converted to an integer as long as it's in
+ the range [min_possible_range, max_possible_range). If not, it is either
+ too large, or too small, or is NaN; in this case return the maximum or
+ minimum possible value. */
+ if (host_float < max_possible_range && host_float >= min_possible_range)
+ return static_cast<LONGEST> (host_float);
+ if (host_float < min_possible_range)
return std::numeric_limits<LONGEST>::min();
- return (LONGEST) host_float;
+ /* This line will be executed if host_float is NaN. */
+ return std::numeric_limits<LONGEST>::max();
}
/* Convert signed integer VAL to a target floating-number of type TYPE
}
+/* Implementation of target_float_ops using the MPFR library
+ mpfr_t as intermediate type. */
+
+#ifdef HAVE_LIBMPFR
+
+#define MPFR_USE_INTMAX_T
+
+#include <mpfr.h>
+
+class mpfr_float_ops : public target_float_ops
+{
+public:
+ std::string to_string (const gdb_byte *addr, const struct type *type,
+ const char *format) const override;
+ bool from_string (gdb_byte *addr, const struct type *type,
+ const std::string &string) const override;
+
+ LONGEST to_longest (const gdb_byte *addr,
+ const struct type *type) const override;
+ void from_longest (gdb_byte *addr, const struct type *type,
+ LONGEST val) const override;
+ void from_ulongest (gdb_byte *addr, const struct type *type,
+ ULONGEST val) const override;
+ double to_host_double (const gdb_byte *addr,
+ const struct type *type) const override;
+ void from_host_double (gdb_byte *addr, const struct type *type,
+ double val) const override;
+ void convert (const gdb_byte *from, const struct type *from_type,
+ gdb_byte *to, const struct type *to_type) const override;
+
+ void binop (enum exp_opcode opcode,
+ const gdb_byte *x, const struct type *type_x,
+ const gdb_byte *y, const struct type *type_y,
+ gdb_byte *res, const struct type *type_res) const override;
+ int compare (const gdb_byte *x, const struct type *type_x,
+ const gdb_byte *y, const struct type *type_y) const override;
+
+private:
+ /* Local wrapper class to handle mpfr_t initalization and cleanup. */
+ class gdb_mpfr
+ {
+ public:
+ mpfr_t val;
+
+ gdb_mpfr (const struct type *type)
+ {
+ const struct floatformat *fmt = floatformat_from_type (type);
+ mpfr_init2 (val, floatformat_precision (fmt));
+ }
+
+ gdb_mpfr (const gdb_mpfr &source)
+ {
+ mpfr_init2 (val, mpfr_get_prec (source.val));
+ }
+
+ ~gdb_mpfr ()
+ {
+ mpfr_clear (val);
+ }
+ };
+
+ void from_target (const struct floatformat *fmt,
+ const gdb_byte *from, gdb_mpfr &to) const;
+ void from_target (const struct type *type,
+ const gdb_byte *from, gdb_mpfr &to) const;
+
+ void to_target (const struct type *type,
+ const gdb_mpfr &from, gdb_byte *to) const;
+ void to_target (const struct floatformat *fmt,
+ const gdb_mpfr &from, gdb_byte *to) const;
+};
+
+
+/* Convert TO/FROM target floating-point format to mpfr_t. */
+
+void
+mpfr_float_ops::from_target (const struct floatformat *fmt,
+ const gdb_byte *orig_from, gdb_mpfr &to) const
+{
+ const gdb_byte *from = orig_from;
+ mpfr_exp_t exponent;
+ unsigned long mant;
+ unsigned int mant_bits, mant_off;
+ int mant_bits_left;
+ int special_exponent; /* It's a NaN, denorm or zero. */
+ enum floatformat_byteorders order;
+ unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES];
+ enum float_kind kind;
+
+ gdb_assert (fmt->totalsize
+ <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT);
+
+ /* Handle non-numbers. */
+ kind = floatformat_classify (fmt, from);
+ if (kind == float_infinite)
+ {
+ mpfr_set_inf (to.val, floatformat_is_negative (fmt, from) ? -1 : 1);
+ return;
+ }
+ if (kind == float_nan)
+ {
+ mpfr_set_nan (to.val);
+ return;
+ }
+
+ order = floatformat_normalize_byteorder (fmt, from, newfrom);
+
+ if (order != fmt->byteorder)
+ from = newfrom;
+
+ if (fmt->split_half)
+ {
+ gdb_mpfr top (to), bot (to);
+
+ from_target (fmt->split_half, from, top);
+ /* Preserve the sign of 0, which is the sign of the top half. */
+ if (mpfr_zero_p (top.val))
+ {
+ mpfr_set (to.val, top.val, MPFR_RNDN);
+ return;
+ }
+ from_target (fmt->split_half,
+ from + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2, bot);
+ mpfr_add (to.val, top.val, bot.val, MPFR_RNDN);
+ return;
+ }
+
+ exponent = get_field (from, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len);
+ /* Note that if exponent indicates a NaN, we can't really do anything useful
+ (not knowing if the host has NaN's, or how to build one). So it will
+ end up as an infinity or something close; that is OK. */
+
+ mant_bits_left = fmt->man_len;
+ mant_off = fmt->man_start;
+ mpfr_set_zero (to.val, 0);
+
+ special_exponent = exponent == 0 || exponent == fmt->exp_nan;
+
+ /* Don't bias NaNs. Use minimum exponent for denorms. For
+ simplicity, we don't check for zero as the exponent doesn't matter.
+ Note the cast to int; exp_bias is unsigned, so it's important to
+ make sure the operation is done in signed arithmetic. */
+ if (!special_exponent)
+ exponent -= fmt->exp_bias;
+ else if (exponent == 0)
+ exponent = 1 - fmt->exp_bias;
+
+ /* Build the result algebraically. Might go infinite, underflow, etc;
+ who cares. */
+
+ /* If this format uses a hidden bit, explicitly add it in now. Otherwise,
+ increment the exponent by one to account for the integer bit. */
+
+ if (!special_exponent)
+ {
+ if (fmt->intbit == floatformat_intbit_no)
+ mpfr_set_ui_2exp (to.val, 1, exponent, MPFR_RNDN);
+ else
+ exponent++;
+ }
+
+ gdb_mpfr tmp (to);
+
+ while (mant_bits_left > 0)
+ {
+ mant_bits = std::min (mant_bits_left, 32);
+
+ mant = get_field (from, order, fmt->totalsize, mant_off, mant_bits);
+
+ mpfr_set_ui (tmp.val, mant, MPFR_RNDN);
+ mpfr_mul_2si (tmp.val, tmp.val, exponent - mant_bits, MPFR_RNDN);
+ mpfr_add (to.val, to.val, tmp.val, MPFR_RNDN);
+ exponent -= mant_bits;
+ mant_off += mant_bits;
+ mant_bits_left -= mant_bits;
+ }
+
+ /* Negate it if negative. */
+ if (get_field (from, order, fmt->totalsize, fmt->sign_start, 1))
+ mpfr_neg (to.val, to.val, MPFR_RNDN);
+}
+
+void
+mpfr_float_ops::from_target (const struct type *type,
+ const gdb_byte *from, gdb_mpfr &to) const
+{
+ from_target (floatformat_from_type (type), from, to);
+}
+
+void
+mpfr_float_ops::to_target (const struct floatformat *fmt,
+ const gdb_mpfr &from, gdb_byte *orig_to) const
+{
+ unsigned char *to = orig_to;
+ mpfr_exp_t exponent;
+ unsigned int mant_bits, mant_off;
+ int mant_bits_left;
+ enum floatformat_byteorders order = fmt->byteorder;
+ unsigned char newto[FLOATFORMAT_LARGEST_BYTES];
+
+ if (order != floatformat_little)
+ order = floatformat_big;
+
+ if (order != fmt->byteorder)
+ to = newto;
+
+ memset (to, 0, floatformat_totalsize_bytes (fmt));
+
+ if (fmt->split_half)
+ {
+ gdb_mpfr top (from), bot (from);
+
+ mpfr_set (top.val, from.val, MPFR_RNDN);
+ /* If the rounded top half is Inf, the bottom must be 0 not NaN
+ or Inf. */
+ if (mpfr_inf_p (top.val))
+ mpfr_set_zero (bot.val, 0);
+ else
+ mpfr_sub (bot.val, from.val, top.val, MPFR_RNDN);
+
+ to_target (fmt->split_half, top, to);
+ to_target (fmt->split_half, bot,
+ to + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2);
+ return;
+ }
+
+ gdb_mpfr tmp (from);
+
+ if (mpfr_zero_p (from.val))
+ goto finalize_byteorder; /* Result is zero */
+
+ mpfr_set (tmp.val, from.val, MPFR_RNDN);
+
+ if (mpfr_nan_p (tmp.val)) /* Result is NaN */
+ {
+ /* From is NaN */
+ put_field (to, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, fmt->exp_nan);
+ /* Be sure it's not infinity, but NaN value is irrel. */
+ put_field (to, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 1);
+ goto finalize_byteorder;
+ }
+
+ /* If negative, set the sign bit. */
+ if (mpfr_sgn (tmp.val) < 0)
+ {
+ put_field (to, order, fmt->totalsize, fmt->sign_start, 1, 1);
+ mpfr_neg (tmp.val, tmp.val, MPFR_RNDN);
+ }
+
+ if (mpfr_inf_p (tmp.val)) /* Result is Infinity. */
+ {
+ /* Infinity exponent is same as NaN's. */
+ put_field (to, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, fmt->exp_nan);
+ /* Infinity mantissa is all zeroes. */
+ put_field (to, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 0);
+ goto finalize_byteorder;
+ }
+
+ mpfr_frexp (&exponent, tmp.val, tmp.val, MPFR_RNDN);
+
+ if (exponent + fmt->exp_bias <= 0)
+ {
+ /* The value is too small to be expressed in the destination
+ type (not enough bits in the exponent. Treat as 0. */
+ put_field (to, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, 0);
+ put_field (to, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 0);
+ goto finalize_byteorder;
+ }
+
+ if (exponent + fmt->exp_bias >= (1 << fmt->exp_len))
+ {
+ /* The value is too large to fit into the destination.
+ Treat as infinity. */
+ put_field (to, order, fmt->totalsize, fmt->exp_start,
+ fmt->exp_len, fmt->exp_nan);
+ put_field (to, order, fmt->totalsize, fmt->man_start,
+ fmt->man_len, 0);
+ goto finalize_byteorder;
+ }
+
+ put_field (to, order, fmt->totalsize, fmt->exp_start, fmt->exp_len,
+ exponent + fmt->exp_bias - 1);
+
+ mant_bits_left = fmt->man_len;
+ mant_off = fmt->man_start;
+ while (mant_bits_left > 0)
+ {
+ unsigned long mant_long;
+
+ mant_bits = mant_bits_left < 32 ? mant_bits_left : 32;
+
+ mpfr_mul_2ui (tmp.val, tmp.val, 32, MPFR_RNDN);
+ mant_long = mpfr_get_ui (tmp.val, MPFR_RNDZ) & 0xffffffffL;
+ mpfr_sub_ui (tmp.val, tmp.val, mant_long, MPFR_RNDZ);
+
+ /* If the integer bit is implicit, then we need to discard it.
+ If we are discarding a zero, we should be (but are not) creating
+ a denormalized number which means adjusting the exponent
+ (I think). */
+ if (mant_bits_left == fmt->man_len
+ && fmt->intbit == floatformat_intbit_no)
+ {
+ mant_long <<= 1;
+ mant_long &= 0xffffffffL;
+ /* If we are processing the top 32 mantissa bits of a doublest
+ so as to convert to a float value with implied integer bit,
+ we will only be putting 31 of those 32 bits into the
+ final value due to the discarding of the top bit. In the
+ case of a small float value where the number of mantissa
+ bits is less than 32, discarding the top bit does not alter
+ the number of bits we will be adding to the result. */
+ if (mant_bits == 32)
+ mant_bits -= 1;
+ }
+
+ if (mant_bits < 32)
+ {
+ /* The bits we want are in the most significant MANT_BITS bits of
+ mant_long. Move them to the least significant. */
+ mant_long >>= 32 - mant_bits;
+ }
+
+ put_field (to, order, fmt->totalsize,
+ mant_off, mant_bits, mant_long);
+ mant_off += mant_bits;
+ mant_bits_left -= mant_bits;
+ }
+
+ finalize_byteorder:
+ /* Do we need to byte-swap the words in the result? */
+ if (order != fmt->byteorder)
+ floatformat_normalize_byteorder (fmt, newto, orig_to);
+}
+
+void
+mpfr_float_ops::to_target (const struct type *type,
+ const gdb_mpfr &from, gdb_byte *to) const
+{
+ /* Ensure possible padding bytes in the target buffer are zeroed out. */
+ memset (to, 0, TYPE_LENGTH (type));
+
+ to_target (floatformat_from_type (type), from, to);
+}
+
+/* Convert the byte-stream ADDR, interpreted as floating-point type TYPE,
+ to a string, optionally using the print format FORMAT. */
+std::string
+mpfr_float_ops::to_string (const gdb_byte *addr,
+ const struct type *type,
+ const char *format) const
+{
+ const struct floatformat *fmt = floatformat_from_type (type);
+
+ /* Unless we need to adhere to a specific format, provide special
+ output for certain cases. */
+ if (format == nullptr)
+ {
+ /* Detect invalid representations. */
+ if (!floatformat_is_valid (fmt, addr))
+ return "<invalid float value>";
+
+ /* Handle NaN and Inf. */
+ enum float_kind kind = floatformat_classify (fmt, addr);
+ if (kind == float_nan)
+ {
+ const char *sign = floatformat_is_negative (fmt, addr)? "-" : "";
+ const char *mantissa = floatformat_mantissa (fmt, addr);
+ return string_printf ("%snan(0x%s)", sign, mantissa);
+ }
+ else if (kind == float_infinite)
+ {
+ const char *sign = floatformat_is_negative (fmt, addr)? "-" : "";
+ return string_printf ("%sinf", sign);
+ }
+ }
+
+ /* Determine the format string to use on the host side. */
+ std::string host_format = floatformat_printf_format (fmt, format, 'R');
+
+ gdb_mpfr tmp (type);
+ from_target (type, addr, tmp);
+
+ int size = mpfr_snprintf (NULL, 0, host_format.c_str (), tmp.val);
+ std::string str (size, '\0');
+ mpfr_sprintf (&str[0], host_format.c_str (), tmp.val);
+
+ return str;
+}
+
+/* Parse string STRING into a target floating-number of type TYPE and
+ store it as byte-stream ADDR. Return whether parsing succeeded. */
+bool
+mpfr_float_ops::from_string (gdb_byte *addr,
+ const struct type *type,
+ const std::string &in) const
+{
+ gdb_mpfr tmp (type);
+
+ char *endptr;
+ mpfr_strtofr (tmp.val, in.c_str (), &endptr, 0, MPFR_RNDN);
+
+ /* We only accept the whole string. */
+ if (*endptr)
+ return false;
+
+ to_target (type, tmp, addr);
+ return true;
+}
+
+/* Convert the byte-stream ADDR, interpreted as floating-point type TYPE,
+ to an integer value (rounding towards zero). */
+LONGEST
+mpfr_float_ops::to_longest (const gdb_byte *addr,
+ const struct type *type) const
+{
+ gdb_mpfr tmp (type);
+ from_target (type, addr, tmp);
+ return mpfr_get_sj (tmp.val, MPFR_RNDZ);
+}
+
+/* Convert signed integer VAL to a target floating-number of type TYPE
+ and store it as byte-stream ADDR. */
+void
+mpfr_float_ops::from_longest (gdb_byte *addr,
+ const struct type *type,
+ LONGEST val) const
+{
+ gdb_mpfr tmp (type);
+ mpfr_set_sj (tmp.val, val, MPFR_RNDN);
+ to_target (type, tmp, addr);
+}
+
+/* Convert unsigned integer VAL to a target floating-number of type TYPE
+ and store it as byte-stream ADDR. */
+void
+mpfr_float_ops::from_ulongest (gdb_byte *addr,
+ const struct type *type,
+ ULONGEST val) const
+{
+ gdb_mpfr tmp (type);
+ mpfr_set_uj (tmp.val, val, MPFR_RNDN);
+ to_target (type, tmp, addr);
+}
+
+/* Convert the byte-stream ADDR, interpreted as floating-point type TYPE,
+ to a floating-point value in the host "double" format. */
+double
+mpfr_float_ops::to_host_double (const gdb_byte *addr,
+ const struct type *type) const
+{
+ gdb_mpfr tmp (type);
+ from_target (type, addr, tmp);
+ return mpfr_get_d (tmp.val, MPFR_RNDN);
+}
+
+/* Convert floating-point value VAL in the host "double" format to a target
+ floating-number of type TYPE and store it as byte-stream ADDR. */
+void
+mpfr_float_ops::from_host_double (gdb_byte *addr,
+ const struct type *type,
+ double val) const
+{
+ gdb_mpfr tmp (type);
+ mpfr_set_d (tmp.val, val, MPFR_RNDN);
+ to_target (type, tmp, addr);
+}
+
+/* Convert a floating-point number of type FROM_TYPE from the target
+ byte-stream FROM to a floating-point number of type TO_TYPE, and
+ store it to the target byte-stream TO. */
+void
+mpfr_float_ops::convert (const gdb_byte *from,
+ const struct type *from_type,
+ gdb_byte *to,
+ const struct type *to_type) const
+{
+ gdb_mpfr from_tmp (from_type), to_tmp (to_type);
+ from_target (from_type, from, from_tmp);
+ mpfr_set (to_tmp.val, from_tmp.val, MPFR_RNDN);
+ to_target (to_type, to_tmp, to);
+}
+
+/* Perform the binary operation indicated by OPCODE, using as operands the
+ target byte streams X and Y, interpreted as floating-point numbers of
+ types TYPE_X and TYPE_Y, respectively. Convert the result to type
+ TYPE_RES and store it into the byte-stream RES. */
+void
+mpfr_float_ops::binop (enum exp_opcode op,
+ const gdb_byte *x, const struct type *type_x,
+ const gdb_byte *y, const struct type *type_y,
+ gdb_byte *res, const struct type *type_res) const
+{
+ gdb_mpfr x_tmp (type_x), y_tmp (type_y), tmp (type_res);
+
+ from_target (type_x, x, x_tmp);
+ from_target (type_y, y, y_tmp);
+
+ switch (op)
+ {
+ case BINOP_ADD:
+ mpfr_add (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ case BINOP_SUB:
+ mpfr_sub (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ case BINOP_MUL:
+ mpfr_mul (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ case BINOP_DIV:
+ mpfr_div (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ case BINOP_EXP:
+ mpfr_pow (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ case BINOP_MIN:
+ mpfr_min (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ case BINOP_MAX:
+ mpfr_max (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN);
+ break;
+
+ default:
+ error (_("Integer-only operation on floating point number."));
+ break;
+ }
+
+ to_target (type_res, tmp, res);
+}
+
+/* Compare the two target byte streams X and Y, interpreted as floating-point
+ numbers of types TYPE_X and TYPE_Y, respectively. Return zero if X and Y
+ are equal, -1 if X is less than Y, and 1 otherwise. */
+int
+mpfr_float_ops::compare (const gdb_byte *x, const struct type *type_x,
+ const gdb_byte *y, const struct type *type_y) const
+{
+ gdb_mpfr x_tmp (type_x), y_tmp (type_y);
+
+ from_target (type_x, x, x_tmp);
+ from_target (type_y, y, y_tmp);
+
+ if (mpfr_equal_p (x_tmp.val, y_tmp.val))
+ return 0;
+ else if (mpfr_less_p (x_tmp.val, y_tmp.val))
+ return -1;
+ else
+ return 1;
+}
+
+#endif
+
+
/* Helper routines operating on decimal floating-point data. */
/* Decimal floating point is one of the extension to IEEE 754, which is
#define OPPOSITE_BYTE_ORDER BFD_ENDIAN_BIG
#endif
- if (gdbarch_byte_order (get_type_arch (type)) == OPPOSITE_BYTE_ORDER)
+ if (type_byte_order (type) == OPPOSITE_BYTE_ORDER)
for (i = 0; i < len; i++)
to[i] = from[len - i - 1];
else
case TYPE_CODE_DECFLOAT:
return (TYPE_LENGTH (type1) == TYPE_LENGTH (type2)
- && (gdbarch_byte_order (get_type_arch (type1))
- == gdbarch_byte_order (get_type_arch (type2))));
+ && (type_byte_order (type1)
+ == type_byte_order (type2)));
default:
gdb_assert_not_reached ("unexpected type code");
}
/* For binary floating-point formats that do not match any host format,
+ use mpfr_t as intermediate format to provide precise target-floating
+ point emulation. However, if the MPFR library is not available,
use the largest host floating-point type as intermediate format. */
case target_float_ops_kind::binary:
{
+#ifdef HAVE_LIBMPFR
+ static mpfr_float_ops binary_float_ops;
+#else
static host_float_ops<long double> binary_float_ops;
+#endif
return &binary_float_ops;
}
projects / deliverable / binutils-gdb.git / blobdiff