[deliverable/binutils-gdb.git] / gdb / dfp.c

/* Decimal floating point support for GDB.

   Copyright (C) 2007-2017 Free Software Foundation, Inc.

   This file is part of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "expression.h"
#include "dfp.h"

/* The order of the following headers is important for making sure
   decNumber structure is large enough to hold decimal128 digits.  */

#include "dpd/decimal128.h"
#include "dpd/decimal64.h"
#include "dpd/decimal32.h"

/* When using decimal128, this is the maximum string length + 1
   (value comes from libdecnumber's DECIMAL128_String constant).  */
#define MAX_DECIMAL_STRING  43

/* In GDB, we are using an array of gdb_byte to represent decimal values.
   They are stored in host byte order.  This routine does the conversion if
   the target byte order is different.  */
static void
match_endianness (const gdb_byte *from, int len, enum bfd_endian byte_order,
		  gdb_byte *to)
{
  int i;

#if WORDS_BIGENDIAN
#define OPPOSITE_BYTE_ORDER BFD_ENDIAN_LITTLE
#else
#define OPPOSITE_BYTE_ORDER BFD_ENDIAN_BIG
#endif

  if (byte_order == OPPOSITE_BYTE_ORDER)
    for (i = 0; i < len; i++)
      to[i] = from[len - i - 1];
  else
    for (i = 0; i < len; i++)
      to[i] = from[i];

  return;
}

/* Helper function to get the appropriate libdecnumber context for each size
   of decimal float.  */
static void
set_decnumber_context (decContext *ctx, int len)
{
  switch (len)
    {
      case 4:
	decContextDefault (ctx, DEC_INIT_DECIMAL32);
	break;
      case 8:
	decContextDefault (ctx, DEC_INIT_DECIMAL64);
	break;
      case 16:
	decContextDefault (ctx, DEC_INIT_DECIMAL128);
	break;
    }

  ctx->traps = 0;
}

/* Check for errors signaled in the decimal context structure.  */
static void
decimal_check_errors (decContext *ctx)
{
  /* An error here could be a division by zero, an overflow, an underflow or
     an invalid operation (from the DEC_Errors constant in decContext.h).
     Since GDB doesn't complain about division by zero, overflow or underflow
     errors for binary floating, we won't complain about them for decimal
     floating either.  */
  if (ctx->status & DEC_IEEE_854_Invalid_operation)
    {
      /* Leave only the error bits in the status flags.  */
      ctx->status &= DEC_IEEE_854_Invalid_operation;
      error (_("Cannot perform operation: %s"),
	     decContextStatusToString (ctx));
    }
}

/* Helper function to convert from libdecnumber's appropriate representation
   for computation to each size of decimal float.  */
static void
decimal_from_number (const decNumber *from, gdb_byte *to, int len)
{
  decContext set;

  set_decnumber_context (&set, len);

  switch (len)
    {
      case 4:
	decimal32FromNumber ((decimal32 *) to, from, &set);
	break;
      case 8:
	decimal64FromNumber ((decimal64 *) to, from, &set);
	break;
      case 16:
	decimal128FromNumber ((decimal128 *) to, from, &set);
	break;
    }
}

/* Helper function to convert each size of decimal float to libdecnumber's
   appropriate representation for computation.  */
static void
decimal_to_number (const gdb_byte *from, int len, decNumber *to)
{
  switch (len)
    {
      case 4:
	decimal32ToNumber ((decimal32 *) from, to);
	break;
      case 8:
	decimal64ToNumber ((decimal64 *) from, to);
	break;
      case 16:
	decimal128ToNumber ((decimal128 *) from, to);
	break;
      default:
	error (_("Unknown decimal floating point type."));
	break;
    }
}

/* Convert decimal type to its string representation.  LEN is the length
   of the decimal type, 4 bytes for decimal32, 8 bytes for decimal64 and
   16 bytes for decimal128.  */
std::string
decimal_to_string (const gdb_byte *decbytes, int len,
		   enum bfd_endian byte_order, const char *format)
{
  gdb_byte dec[16];

  match_endianness (decbytes, len, byte_order, dec);

  if (format != nullptr)
    {
      /* We don't handle format strings (yet).  If the host printf supports
	 decimal floating point types, just use this.  Otherwise, fall back
	 to printing the number while ignoring the format string.  */
#if defined (PRINTF_HAS_DECFLOAT)
      /* FIXME: This makes unwarranted assumptions about the host ABI!  */
      return string_printf (format, dec);
#endif
    }

  std::string result;
  result.resize (MAX_DECIMAL_STRING);

  switch (len)
    {
      case 4:
	decimal32ToString ((decimal32 *) dec, &result[0]);
	break;
      case 8:
	decimal64ToString ((decimal64 *) dec, &result[0]);
	break;
      case 16:
	decimal128ToString ((decimal128 *) dec, &result[0]);
	break;
      default:
	error (_("Unknown decimal floating point type."));
	break;
    }

  return result;
}

/* Convert the string form of a decimal value to its decimal representation.
   LEN is the length of the decimal type, 4 bytes for decimal32, 8 bytes for
   decimal64 and 16 bytes for decimal128.  */
bool
decimal_from_string (gdb_byte *decbytes, int len, enum bfd_endian byte_order,
		     const std::string &string)
{
  decContext set;
  gdb_byte dec[16];

  set_decnumber_context (&set, len);

  switch (len)
    {
      case 4:
	decimal32FromString ((decimal32 *) dec, string.c_str (), &set);
	break;
      case 8:
	decimal64FromString ((decimal64 *) dec, string.c_str (), &set);
	break;
      case 16:
	decimal128FromString ((decimal128 *) dec, string.c_str (), &set);
	break;
      default:
	error (_("Unknown decimal floating point type."));
	break;
    }

  match_endianness (dec, len, byte_order, decbytes);

  /* Check for errors in the DFP operation.  */
  decimal_check_errors (&set);

  return true;
}

/* Converts a LONGEST to a decimal float of specified LEN bytes.  */
void
decimal_from_longest (LONGEST from,
		      gdb_byte *to, int len, enum bfd_endian byte_order)
{
  gdb_byte dec[16];
  decNumber number;
  if ((int32_t) from != from)
    /* libdecnumber can convert only 32-bit integers.  */
    error (_("Conversion of large integer to a "
	     "decimal floating type is not supported."));

  decNumberFromInt32 (&number, (int32_t) from);

  decimal_from_number (&number, dec, len);
  match_endianness (dec, len, byte_order, to);
}

/* Converts a ULONGEST to a decimal float of specified LEN bytes.  */
void
decimal_from_ulongest (ULONGEST from,
		       gdb_byte *to, int len, enum bfd_endian byte_order)
{
  gdb_byte dec[16];
  decNumber number;

  if ((uint32_t) from != from)
    /* libdecnumber can convert only 32-bit integers.  */
    error (_("Conversion of large integer to a "
	     "decimal floating type is not supported."));

  decNumberFromUInt32 (&number, (uint32_t) from);

  decimal_from_number (&number, dec, len);
  match_endianness (dec, len, byte_order, to);
}

/* Converts a decimal float of LEN bytes to a LONGEST.  */
LONGEST
decimal_to_longest (const gdb_byte *from, int len, enum bfd_endian byte_order)
{
  /* libdecnumber has a function to convert from decimal to integer, but
     it doesn't work when the decimal number has a fractional part.  */
  std::string str = decimal_to_string (from, len, byte_order);
  return strtoll (str.c_str (), NULL, 10);
}

/* Converts a value of a float type to a decimal float of
   specified LEN bytes.

   This is an ugly way to do the conversion, but libdecnumber does
   not offer a direct way to do it.  */
void
decimal_from_doublest (DOUBLEST from,
		       gdb_byte *to, int len, enum bfd_endian byte_order)
{
  std::string str = string_printf ("%.30" DOUBLEST_PRINT_FORMAT, from);
  decimal_from_string (to, len, byte_order, str);
}

/* Converts a decimal float of LEN bytes to a double value.  */
DOUBLEST
decimal_to_doublest (const gdb_byte *from, int len, enum bfd_endian byte_order)
{
  /* This is an ugly way to do the conversion, but libdecnumber does
     not offer a direct way to do it.  */
  std::string str = decimal_to_string (from, len, byte_order);
  return strtod (str.c_str (), NULL);
}

/* Perform operation OP with operands X and Y with sizes LEN_X and LEN_Y
   and byte orders BYTE_ORDER_X and BYTE_ORDER_Y, and store value in
   RESULT with size LEN_RESULT and byte order BYTE_ORDER_RESULT.  */
void
decimal_binop (enum exp_opcode op,
	       const gdb_byte *x, int len_x, enum bfd_endian byte_order_x,
	       const gdb_byte *y, int len_y, enum bfd_endian byte_order_y,
	       gdb_byte *result, int len_result,
	       enum bfd_endian byte_order_result)
{
  decContext set;
  decNumber number1, number2, number3;
  gdb_byte dec1[16], dec2[16], dec3[16];

  match_endianness (x, len_x, byte_order_x, dec1);
  match_endianness (y, len_y, byte_order_y, dec2);

  decimal_to_number (dec1, len_x, &number1);
  decimal_to_number (dec2, len_y, &number2);

  set_decnumber_context (&set, len_result);

  switch (op)
    {
      case BINOP_ADD:
	decNumberAdd (&number3, &number1, &number2, &set);
	break;
      case BINOP_SUB:
	decNumberSubtract (&number3, &number1, &number2, &set);
	break;
      case BINOP_MUL:
	decNumberMultiply (&number3, &number1, &number2, &set);
	break;
      case BINOP_DIV:
	decNumberDivide (&number3, &number1, &number2, &set);
	break;
      case BINOP_EXP:
	decNumberPower (&number3, &number1, &number2, &set);
	break;
     default:
	error (_("Operation not valid for decimal floating point number."));
	break;
    }

  /* Check for errors in the DFP operation.  */
  decimal_check_errors (&set);

  decimal_from_number (&number3, dec3, len_result);

  match_endianness (dec3, len_result, byte_order_result, result);
}

/* Returns true if X (which is LEN bytes wide) is the number zero.  */
int
decimal_is_zero (const gdb_byte *x, int len, enum bfd_endian byte_order)
{
  decNumber number;
  gdb_byte dec[16];

  match_endianness (x, len, byte_order, dec);
  decimal_to_number (dec, len, &number);

  return decNumberIsZero (&number);
}

/* Compares two numbers numerically.  If X is less than Y then the return value
   will be -1.  If they are equal, then the return value will be 0.  If X is
   greater than the Y then the return value will be 1.  */
int
decimal_compare (const gdb_byte *x, int len_x, enum bfd_endian byte_order_x,
		 const gdb_byte *y, int len_y, enum bfd_endian byte_order_y)
{
  decNumber number1, number2, result;
  decContext set;
  gdb_byte dec1[16], dec2[16];
  int len_result;

  match_endianness (x, len_x, byte_order_x, dec1);
  match_endianness (y, len_y, byte_order_y, dec2);

  decimal_to_number (dec1, len_x, &number1);
  decimal_to_number (dec2, len_y, &number2);

  /* Perform the comparison in the larger of the two sizes.  */
  len_result = len_x > len_y ? len_x : len_y;
  set_decnumber_context (&set, len_result);

  decNumberCompare (&result, &number1, &number2, &set);

  /* Check for errors in the DFP operation.  */
  decimal_check_errors (&set);

  if (decNumberIsNaN (&result))
    error (_("Comparison with an invalid number (NaN)."));
  else if (decNumberIsZero (&result))
    return 0;
  else if (decNumberIsNegative (&result))
    return -1;
  else
    return 1;
}

/* Convert a decimal value from a decimal type with LEN_FROM bytes to a
   decimal type with LEN_TO bytes.  */
void
decimal_convert (const gdb_byte *from, int len_from,
		 enum bfd_endian byte_order_from, gdb_byte *to, int len_to,
		 enum bfd_endian byte_order_to)
{
  decNumber number;
  gdb_byte dec[16];

  match_endianness (from, len_from, byte_order_from, dec);

  decimal_to_number (dec, len_from, &number);
  decimal_from_number (&number, dec, len_to);

  match_endianness (dec, len_to, byte_order_to, to);
}
Commit	Line	Data
9b913628 TJB	1	/* Decimal floating point support for GDB.
9b913628 TJB	2
61baf725	3	Copyright (C) 2007-2017 Free Software Foundation, Inc.
9b913628 TJB	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 3 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	19
	20	#include "defs.h"
4ef30785	21	#include "expression.h"
4ef30785	22	#include "dfp.h"
9b913628 TJB	23
	24	/* The order of the following headers is important for making sure
	25	decNumber structure is large enough to hold decimal128 digits. */
	26
	27	#include "dpd/decimal128.h"
	28	#include "dpd/decimal64.h"
	29	#include "dpd/decimal32.h"
	30
3b4b2f16 UW	31	/* When using decimal128, this is the maximum string length + 1
	32	(value comes from libdecnumber's DECIMAL128_String constant). */
	33	#define MAX_DECIMAL_STRING 43
	34
9b913628 TJB	35	/* In GDB, we are using an array of gdb_byte to represent decimal values.
	36	They are stored in host byte order. This routine does the conversion if
	37	the target byte order is different. */
	38	static void
e17a4113 UW	39	match_endianness (const gdb_byte *from, int len, enum bfd_endian byte_order,
e17a4113 UW	40	gdb_byte *to)
9b913628 TJB	41	{
	42	int i;
	43
	44	#if WORDS_BIGENDIAN
	45	#define OPPOSITE_BYTE_ORDER BFD_ENDIAN_LITTLE
	46	#else
	47	#define OPPOSITE_BYTE_ORDER BFD_ENDIAN_BIG
	48	#endif
	49
e17a4113	50	if (byte_order == OPPOSITE_BYTE_ORDER)
9b913628 TJB	51	for (i = 0; i < len; i++)
	52	to[i] = from[len - i - 1];
	53	else
	54	for (i = 0; i < len; i++)
	55	to[i] = from[i];
	56
	57	return;
	58	}
	59
4ef30785 TJB	60	/* Helper function to get the appropriate libdecnumber context for each size
	61	of decimal float. */
	62	static void
	63	set_decnumber_context (decContext *ctx, int len)
	64	{
	65	switch (len)
	66	{
	67	case 4:
	68	decContextDefault (ctx, DEC_INIT_DECIMAL32);
	69	break;
	70	case 8:
	71	decContextDefault (ctx, DEC_INIT_DECIMAL64);
	72	break;
	73	case 16:
	74	decContextDefault (ctx, DEC_INIT_DECIMAL128);
	75	break;
	76	}
	77
	78	ctx->traps = 0;
	79	}
	80
	81	/* Check for errors signaled in the decimal context structure. */
	82	static void
	83	decimal_check_errors (decContext *ctx)
	84	{
	85	/* An error here could be a division by zero, an overflow, an underflow or
	86	an invalid operation (from the DEC_Errors constant in decContext.h).
	87	Since GDB doesn't complain about division by zero, overflow or underflow
	88	errors for binary floating, we won't complain about them for decimal
	89	floating either. */
	90	if (ctx->status & DEC_IEEE_854_Invalid_operation)
	91	{
	92	/* Leave only the error bits in the status flags. */
	93	ctx->status &= DEC_IEEE_854_Invalid_operation;
3e43a32a MS	94	error (_("Cannot perform operation: %s"),
3e43a32a MS	95	decContextStatusToString (ctx));
4ef30785 TJB	96	}
	97	}
	98
	99	/* Helper function to convert from libdecnumber's appropriate representation
	100	for computation to each size of decimal float. */
	101	static void
	102	decimal_from_number (const decNumber from, gdb_byte to, int len)
	103	{
	104	decContext set;
	105
	106	set_decnumber_context (&set, len);
	107
	108	switch (len)
	109	{
	110	case 4:
	111	decimal32FromNumber ((decimal32 *) to, from, &set);
	112	break;
	113	case 8:
	114	decimal64FromNumber ((decimal64 *) to, from, &set);
	115	break;
	116	case 16:
	117	decimal128FromNumber ((decimal128 *) to, from, &set);
	118	break;
	119	}
	120	}
	121
	122	/* Helper function to convert each size of decimal float to libdecnumber's
	123	appropriate representation for computation. */
	124	static void
	125	decimal_to_number (const gdb_byte from, int len, decNumber to)
	126	{
	127	switch (len)
	128	{
	129	case 4:
	130	decimal32ToNumber ((decimal32 *) from, to);
	131	break;
	132	case 8:
	133	decimal64ToNumber ((decimal64 *) from, to);
	134	break;
	135	case 16:
	136	decimal128ToNumber ((decimal128 *) from, to);
	137	break;
	138	default:
b37520b6	139	error (_("Unknown decimal floating point type."));
4ef30785 TJB	140	break;
	141	}
	142	}
	143
9b913628 TJB	144	/* Convert decimal type to its string representation. LEN is the length
	145	of the decimal type, 4 bytes for decimal32, 8 bytes for decimal64 and
	146	16 bytes for decimal128. */
3b4b2f16	147	std::string
e17a4113	148	decimal_to_string (const gdb_byte *decbytes, int len,
16e812b2	149	enum bfd_endian byte_order, const char *format)
9b913628 TJB	150	{
	151	gdb_byte dec[16];
	152
e17a4113	153	match_endianness (decbytes, len, byte_order, dec);
4ef30785	154
16e812b2 UW	155	if (format != nullptr)
	156	{
	157	/* We don't handle format strings (yet). If the host printf supports
	158	decimal floating point types, just use this. Otherwise, fall back
	159	to printing the number while ignoring the format string. */
	160	#if defined (PRINTF_HAS_DECFLOAT)
	161	/* FIXME: This makes unwarranted assumptions about the host ABI! */
	162	return string_printf (format, dec);
	163	#endif
	164	}
	165
3b4b2f16 UW	166	std::string result;
	167	result.resize (MAX_DECIMAL_STRING);
	168
9b913628 TJB	169	switch (len)
	170	{
	171	case 4:
3b4b2f16	172	decimal32ToString ((decimal32 *) dec, &result[0]);
9b913628 TJB	173	break;
9b913628 TJB	174	case 8:
3b4b2f16	175	decimal64ToString ((decimal64 *) dec, &result[0]);
9b913628 TJB	176	break;
9b913628 TJB	177	case 16:
3b4b2f16	178	decimal128ToString ((decimal128 *) dec, &result[0]);
9b913628 TJB	179	break;
9b913628 TJB	180	default:
a4ae0ca1	181	error (_("Unknown decimal floating point type."));
9b913628 TJB	182	break;
9b913628 TJB	183	}
3b4b2f16 UW	184
3b4b2f16 UW	185	return result;
9b913628 TJB	186	}
	187
	188	/* Convert the string form of a decimal value to its decimal representation.
	189	LEN is the length of the decimal type, 4 bytes for decimal32, 8 bytes for
	190	decimal64 and 16 bytes for decimal128. */
3b4b2f16	191	bool
e17a4113	192	decimal_from_string (gdb_byte *decbytes, int len, enum bfd_endian byte_order,
09a7c6aa	193	const std::string &string)
9b913628 TJB	194	{
	195	decContext set;
	196	gdb_byte dec[16];
	197
4ef30785 TJB	198	set_decnumber_context (&set, len);
4ef30785 TJB	199
9b913628 TJB	200	switch (len)
	201	{
	202	case 4:
3b4b2f16	203	decimal32FromString ((decimal32 *) dec, string.c_str (), &set);
9b913628 TJB	204	break;
9b913628 TJB	205	case 8:
3b4b2f16	206	decimal64FromString ((decimal64 *) dec, string.c_str (), &set);
9b913628 TJB	207	break;
9b913628 TJB	208	case 16:
3b4b2f16	209	decimal128FromString ((decimal128 *) dec, string.c_str (), &set);
9b913628 TJB	210	break;
9b913628 TJB	211	default:
a4ae0ca1	212	error (_("Unknown decimal floating point type."));
9b913628 TJB	213	break;
	214	}
	215
e17a4113	216	match_endianness (dec, len, byte_order, decbytes);
9b913628	217
4ef30785 TJB	218	/* Check for errors in the DFP operation. */
	219	decimal_check_errors (&set);
	220
3b4b2f16	221	return true;
9b913628	222	}
4ef30785	223
3b4b2f16	224	/* Converts a LONGEST to a decimal float of specified LEN bytes. */
4ef30785	225	void
3b4b2f16 UW	226	decimal_from_longest (LONGEST from,
3b4b2f16 UW	227	gdb_byte *to, int len, enum bfd_endian byte_order)
4ef30785	228	{
4ef30785 TJB	229	gdb_byte dec[16];
4ef30785 TJB	230	decNumber number;
3b4b2f16 UW	231	if ((int32_t) from != from)
	232	/* libdecnumber can convert only 32-bit integers. */
	233	error (_("Conversion of large integer to a "
	234	"decimal floating type is not supported."));
4ef30785	235
3b4b2f16	236	decNumberFromInt32 (&number, (int32_t) from);
4ef30785	237
3b4b2f16 UW	238	decimal_from_number (&number, dec, len);
	239	match_endianness (dec, len, byte_order, to);
	240	}
	241
	242	/* Converts a ULONGEST to a decimal float of specified LEN bytes. */
	243	void
	244	decimal_from_ulongest (ULONGEST from,
	245	gdb_byte *to, int len, enum bfd_endian byte_order)
	246	{
	247	gdb_byte dec[16];
	248	decNumber number;
	249
	250	if ((uint32_t) from != from)
4ef30785	251	/* libdecnumber can convert only 32-bit integers. */
3e43a32a MS	252	error (_("Conversion of large integer to a "
3e43a32a MS	253	"decimal floating type is not supported."));
4ef30785	254
3b4b2f16	255	decNumberFromUInt32 (&number, (uint32_t) from);
4ef30785 TJB	256
4ef30785 TJB	257	decimal_from_number (&number, dec, len);
e17a4113	258	match_endianness (dec, len, byte_order, to);
4ef30785 TJB	259	}
4ef30785 TJB	260
3b4b2f16 UW	261	/* Converts a decimal float of LEN bytes to a LONGEST. */
	262	LONGEST
	263	decimal_to_longest (const gdb_byte *from, int len, enum bfd_endian byte_order)
	264	{
	265	/* libdecnumber has a function to convert from decimal to integer, but
	266	it doesn't work when the decimal number has a fractional part. */
	267	std::string str = decimal_to_string (from, len, byte_order);
	268	return strtoll (str.c_str (), NULL, 10);
	269	}
	270
4ef30785 TJB	271	/* Converts a value of a float type to a decimal float of
	272	specified LEN bytes.
	273
	274	This is an ugly way to do the conversion, but libdecnumber does
	275	not offer a direct way to do it. */
	276	void
3b4b2f16	277	decimal_from_doublest (DOUBLEST from,
e17a4113	278	gdb_byte *to, int len, enum bfd_endian byte_order)
4ef30785	279	{
3b4b2f16 UW	280	std::string str = string_printf ("%.30" DOUBLEST_PRINT_FORMAT, from);
3b4b2f16 UW	281	decimal_from_string (to, len, byte_order, str);
4ef30785 TJB	282	}
	283
	284	/* Converts a decimal float of LEN bytes to a double value. */
	285	DOUBLEST
e17a4113	286	decimal_to_doublest (const gdb_byte *from, int len, enum bfd_endian byte_order)
4ef30785	287	{
4ef30785 TJB	288	/* This is an ugly way to do the conversion, but libdecnumber does
4ef30785 TJB	289	not offer a direct way to do it. */
3b4b2f16 UW	290	std::string str = decimal_to_string (from, len, byte_order);
3b4b2f16 UW	291	return strtod (str.c_str (), NULL);
4ef30785 TJB	292	}
4ef30785 TJB	293
289bd67a	294	/* Perform operation OP with operands X and Y with sizes LEN_X and LEN_Y
e17a4113 UW	295	and byte orders BYTE_ORDER_X and BYTE_ORDER_Y, and store value in
e17a4113 UW	296	RESULT with size LEN_RESULT and byte order BYTE_ORDER_RESULT. */
4ef30785	297	void
e17a4113 UW	298	decimal_binop (enum exp_opcode op,
	299	const gdb_byte *x, int len_x, enum bfd_endian byte_order_x,
	300	const gdb_byte *y, int len_y, enum bfd_endian byte_order_y,
	301	gdb_byte *result, int len_result,
	302	enum bfd_endian byte_order_result)
4ef30785 TJB	303	{
	304	decContext set;
	305	decNumber number1, number2, number3;
	306	gdb_byte dec1[16], dec2[16], dec3[16];
	307
e17a4113 UW	308	match_endianness (x, len_x, byte_order_x, dec1);
e17a4113 UW	309	match_endianness (y, len_y, byte_order_y, dec2);
4ef30785	310
289bd67a UW	311	decimal_to_number (dec1, len_x, &number1);
289bd67a UW	312	decimal_to_number (dec2, len_y, &number2);
4ef30785	313
289bd67a	314	set_decnumber_context (&set, len_result);
4ef30785 TJB	315
	316	switch (op)
	317	{
	318	case BINOP_ADD:
	319	decNumberAdd (&number3, &number1, &number2, &set);
	320	break;
	321	case BINOP_SUB:
	322	decNumberSubtract (&number3, &number1, &number2, &set);
	323	break;
	324	case BINOP_MUL:
	325	decNumberMultiply (&number3, &number1, &number2, &set);
	326	break;
	327	case BINOP_DIV:
	328	decNumberDivide (&number3, &number1, &number2, &set);
	329	break;
	330	case BINOP_EXP:
	331	decNumberPower (&number3, &number1, &number2, &set);
	332	break;
66c02b9e UW	333	default:
66c02b9e UW	334	error (_("Operation not valid for decimal floating point number."));
4ef30785 TJB	335	break;
	336	}
	337
	338	/* Check for errors in the DFP operation. */
	339	decimal_check_errors (&set);
	340
289bd67a	341	decimal_from_number (&number3, dec3, len_result);
4ef30785	342
e17a4113	343	match_endianness (dec3, len_result, byte_order_result, result);
4ef30785 TJB	344	}
	345
	346	/* Returns true if X (which is LEN bytes wide) is the number zero. */
	347	int
e17a4113	348	decimal_is_zero (const gdb_byte *x, int len, enum bfd_endian byte_order)
4ef30785 TJB	349	{
	350	decNumber number;
	351	gdb_byte dec[16];
	352
e17a4113	353	match_endianness (x, len, byte_order, dec);
4ef30785 TJB	354	decimal_to_number (dec, len, &number);
	355
	356	return decNumberIsZero (&number);
	357	}
	358
	359	/* Compares two numbers numerically. If X is less than Y then the return value
	360	will be -1. If they are equal, then the return value will be 0. If X is
	361	greater than the Y then the return value will be 1. */
	362	int
e17a4113 UW	363	decimal_compare (const gdb_byte *x, int len_x, enum bfd_endian byte_order_x,
e17a4113 UW	364	const gdb_byte *y, int len_y, enum bfd_endian byte_order_y)
4ef30785 TJB	365	{
	366	decNumber number1, number2, result;
	367	decContext set;
	368	gdb_byte dec1[16], dec2[16];
	369	int len_result;
	370
e17a4113 UW	371	match_endianness (x, len_x, byte_order_x, dec1);
e17a4113 UW	372	match_endianness (y, len_y, byte_order_y, dec2);
4ef30785	373
289bd67a UW	374	decimal_to_number (dec1, len_x, &number1);
289bd67a UW	375	decimal_to_number (dec2, len_y, &number2);
4ef30785	376
289bd67a UW	377	/* Perform the comparison in the larger of the two sizes. */
289bd67a UW	378	len_result = len_x > len_y ? len_x : len_y;
4ef30785 TJB	379	set_decnumber_context (&set, len_result);
	380
	381	decNumberCompare (&result, &number1, &number2, &set);
	382
	383	/* Check for errors in the DFP operation. */
	384	decimal_check_errors (&set);
	385
	386	if (decNumberIsNaN (&result))
	387	error (_("Comparison with an invalid number (NaN)."));
	388	else if (decNumberIsZero (&result))
	389	return 0;
	390	else if (decNumberIsNegative (&result))
	391	return -1;
	392	else
	393	return 1;
	394	}
	395
	396	/* Convert a decimal value from a decimal type with LEN_FROM bytes to a
	397	decimal type with LEN_TO bytes. */
	398	void
e17a4113 UW	399	decimal_convert (const gdb_byte *from, int len_from,
	400	enum bfd_endian byte_order_from, gdb_byte *to, int len_to,
	401	enum bfd_endian byte_order_to)
4ef30785 TJB	402	{
4ef30785 TJB	403	decNumber number;
cd0b43b1 JM	404	gdb_byte dec[16];
cd0b43b1 JM	405
e17a4113	406	match_endianness (from, len_from, byte_order_from, dec);
cd0b43b1 JM	407
	408	decimal_to_number (dec, len_from, &number);
	409	decimal_from_number (&number, dec, len_to);
4ef30785	410
e17a4113	411	match_endianness (dec, len_to, byte_order_to, to);
4ef30785	412	}