/* Handle conversion from binary integers, floats and decimal types
   Copyright (C) 2007,2008 IBM Corporation.
   Copyright (C) 2014-2015 Free Software Foundation, Inc.

   Author(s): Pete Eberlein <eberlein@us.ibm.com>

   The Decimal Floating Point C Library is free software; you can
   redistribute it and/or modify it under the terms of the GNU Lesser
   General Public License version 2.1.

   The Decimal Floating Point C Library 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 Lesser General Public License version 2.1 for more details.

   You should have received a copy of the GNU Lesser General Public
   License version 2.1 along with the Decimal Floating Point C Library;
   if not, write to the Free Software Foundation, Inc., 51 Franklin
   Street, Fifth Floor, Boston, MA 02110-1301 USA.

   Please see dfp/COPYING.txt for more information.  */


#include <math.h>
#include <ieee754r_private.h>
#include <stdlib.h>

/* This is a horrible hack. When compiling C code, TFmode is long double on ppc64le, whatever
   this may be (ibm128 or ieee128).  However, the intrinsic function calls generated by libgcc
   always use the "tf" name to represent ibm128, and "kf" for ieee128.  We need to adjust
   the types to ensure we override the correct intrinsic conversion routines for the format,
   not the type. */
#if defined (__powerpc64__) && __LDBL_MANT_DIG__ == 113
typedef __ibm128 ldouble;
#else
typedef long double ldouble;
#endif

/* decimal source */
#if defined DECIMAL_TO_INTEGER || defined DECIMAL_TO_BINARY || defined DECIMAL_TO_DECIMAL

#if SRC==32
# define SRC_TYPE _Decimal32
# define IEEE_SRC_TYPE decimal32
# define SRC_LITERAL(n) n##DF
# define SRC_KIND sd
# define SIGNBIT __signbitd32
# define CLASSIFY(x) __fpclassifyd32(x)
#endif

#if SRC==64
# define SRC_TYPE _Decimal64
# define IEEE_SRC_TYPE decimal64
# define SRC_LITERAL(n) n##DD
# define SRC_KIND dd
# define SIGNBIT __signbitd64
# define CLASSIFY(x) __fpclassifyd64(x)
#endif

#if SRC==128
# define SRC_TYPE _Decimal128
# define IEEE_SRC_TYPE decimal128
# define SRC_LITERAL(n) n##DL
# define SRC_KIND td
# define SIGNBIT __signbitd128
# define CLASSIFY(x) __fpclassifyd128(x)
#endif

extern int SIGNBIT (SRC_TYPE);


#define DECIMAL_SIZE SRC

#endif //DECIMAL_TO_INTEGER || DECIMAL_TO_BINARY || DECIMAL_TO_DECIMAL

#define LDBL_FMT_IBM 1
#define LDBL_FMT_IEEE128 2
#define LDBL_FMT_INTEL 3
#define LDBL_FMT_IEEE64 4

/* Determine which long double we are using. */
#if __LDBL_MANT_DIG__ == 64
#define LDBL_FMT LDBL_FMT_INTEL
#define LDBL_GCC_NAME xf
#elif __LDBL_MANT_DIG__ == 113
#define LDBL_FMT LDBL_FMT_IEEE128
#define LDBL_GCC_NAME tf
#elif __LDBL_MANT_DIG__ == 106
#define LDBL_FMT LDBL_FMT_IBM
#define LDBL_GCC_NAME tf
#else
#error "Unsupported long double type"
#endif


/* float source */
#if defined BINARY_TO_DECIMAL

/* Borrowed from glibc. We assume no snan and GCC > 4.4 */
#define CLASSIFY(x) __builtin_fpclassify (FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, x)

#if SRC==32
#define SRC_TYPE float
#define SRC_LITERAL(n) n##f
#define SRC_KIND sf
#define SIGNBIT __builtin_signbitf
#endif

#if SRC==64
#define SRC_TYPE double
#define SRC_LITERAL(n) n##d
#define SRC_KIND df
#define SIGNBIT __builtin_signbit
#endif

#if SRC==128
#define SRC_TYPE ldouble
#define SRC_LITERAL(n) n##l
#define SRC_KIND LDBL_GCC_NAME

#if defined (__powerpc64__) && __LDBL_MANT_DIG__ == 113
/* This is type-generic on any gcc which supports ldbl=ieee128.  */
#define SIGNBIT __builtin_signbit
#else
#define SIGNBIT __builtin_signbitl
#endif

#endif

extern int SIGNBIT (SRC_TYPE);

#endif // BINARY_TO_DECIMAL


/* integer source */
#if defined INTEGER_TO_DECIMAL

#if SRC==32
#if defined UNSIGNED
#define SRC_TYPE unsigned int
#define INT_FMT "%u"
#define CAST_FOR_FMT(A) (unsigned int)A
#else
#define SRC_TYPE int
#define INT_FMT "%d"
#define CAST_FOR_FMT(A) (int)A
#endif
#define SRC_LITERAL(n) n
#define SRC_KIND si
#endif

#if SRC==64
#if defined UNSIGNED
#define SRC_TYPE unsigned long long
#define INT_FMT "%llu"
#define CAST_FOR_FMT(A) (unsigned long long)A
#else
#define SRC_TYPE long long
#define INT_FMT "%lld"
#define CAST_FOR_FMT(A) (long long)A
#endif
#define SRC_LITERAL(n) n
#define SRC_KIND di
#endif

#endif // INTEGER_TO_DECIMAL



/* decimal dest */
#if defined DECIMAL_TO_DECIMAL || defined INTEGER_TO_DECIMAL || defined BINARY_TO_DECIMAL

#if DEST==32
#define DEST_TYPE _Decimal32
#define IEEE_DEST_TYPE decimal32
#define DEST_LITERAL(n) n##DF
#define DEST_KIND sd
#endif

#if DEST==64
#define DEST_TYPE _Decimal64
#define IEEE_DEST_TYPE decimal64
#define DEST_LITERAL(n) n##DD
#define DEST_KIND dd
#endif

#if DEST==128
#define DEST_TYPE _Decimal128
#define IEEE_DEST_TYPE decimal128
#define DEST_LITERAL(n) n##DL
#define DEST_KIND td
#endif

#define DEST_INFINITY DEC_INFINITY
#define DEST_NAN DEC_NAN

#if defined DECIMAL_SIZE
#if DECIMAL_SIZE < DEST
#undef DECIMAL_SIZE
#define DECIMAL_SIZE DEST
#endif
#endif

#define CONTEXT_INIT PASTE(DEC_INIT_DECIMAL,DEST)

#endif //DECIMAL_TO_DECIMAL || INTEGER_TO_DECIMAL || BINARY_TO_DECIMAL


/* float dest */
#if defined DECIMAL_TO_BINARY

#if DEST==32
#define DEST_TYPE       float
#define DEST_LITERAL(n) n##F
#define DEST_KIND       sf
#define DEST_INFINITY   __builtin_inff ()
#define DEST_NAN        __builtin_nanf ("")
#endif

#if DEST==64
#define DEST_TYPE       double
#define DEST_LITERAL(n) n
#define DEST_KIND       df
#define DEST_INFINITY   __builtin_inf ()
#define DEST_NAN        __builtin_nan ("")
#endif

#if DEST==128
#define DEST_TYPE       ldouble
#define DEST_LITERAL(n) n##L
#define DEST_KIND       LDBL_GCC_NAME
#define DEST_INFINITY   __builtin_infl ()
#define DEST_NAN        __builtin_nanl ("")
#endif


#endif //DECIMAL_TO_BINARY


/* integer dest */
#if defined DECIMAL_TO_INTEGER

#if DEST==32
#if defined UNSIGNED
#define DEST_TYPE unsigned int
#define STR_TO_INT strtoul
#else
#define DEST_TYPE int
#define STR_TO_INT strtol
#endif
#define DEST_LITERAL(n) n
#define DEST_KIND si
#endif

#if DEST==64
#if defined UNSIGNED
#define DEST_TYPE unsigned long long
#define STR_TO_INT strtoull
#else
#define DEST_TYPE long long
#define STR_TO_INT strtoll
#endif
#define DEST_LITERAL(n) n
#define DEST_KIND di
#endif

#endif //DECIMAL_TO_INTEGER

extern ldouble binpowof10[];
extern const _Decimal128 decpowof2[];

#define BINPOWOF10 binpowof10
#define BINPOWOF10_LIMIT 308
#define POWOF10_MIN_DENORM_DBL_EXP 324
#define POWOF10_MIN_DENORM_FLT_EXP 45
#define POWOF10_MIN_DENORM_DBL_MAN 49406564584124654LL
#define POWOF10_MIN_DENORM_FLT_MAN 1401298460000000LL

#define DECPOWOF2 decpowof2

#define FREXPSF		__builtin_frexpf
#define FREXPDF		__builtin_frexp
#define FREXPTF		__builtin_frexpl

#ifndef PASTE
# define PASTE(a,b) PASTE2(a,b)
# define PASTE2(x,y) x##y
#endif
#define PASTE4(a,b,c,d) PASTE(PASTE(a,b),PASTE(c,d))
#define PASTE5(a,b,c,d,e) PASTE(PASTE4(a,b,c,d),e)

#if defined DECIMAL_TO_DECIMAL
#define FUNCTION_NAME PASTE4(NAME,SRC_KIND,DEST_KIND,2)
#else
#define FUNCTION_NAME PASTE4(NAME,SRC_KIND,DEST_KIND,)
#endif

/* Functions will need to be prefixed with __bid_ or __dpd_ depending on 
 * how GCC was configured. --enable-decimal-float=[bid,dpd] */
#if __DECIMAL_BID_FORMAT__==1
#define PREFIXED_FUNCTION_NAME  PASTE(__bid_,FUNCTION_NAME)
#else
/* #define PREFIXED_FUNCTION_NAME  PASTE(__dfp_,FUNCTION_NAME) */
#define PREFIXED_FUNCTION_NAME  PASTE(__dpd_,FUNCTION_NAME)
#endif

#if (SRC == 128 && (defined DECIMAL_TO_DECIMAL || defined DECIMAL_TO_INTEGER)) || \
    (DEST == 128 && (defined DECIMAL_TO_DECIMAL || defined INTEGER_TO_DECIMAL))
#include "decimal128.h"
#endif
#if (SRC == 64 && (defined DECIMAL_TO_DECIMAL || defined DECIMAL_TO_INTEGER)) || \
    (DEST == 64 && (defined DECIMAL_TO_DECIMAL || defined INTEGER_TO_DECIMAL))
#include "decimal64.h"
#endif
#if (SRC == 32 && (defined DECIMAL_TO_DECIMAL || defined DECIMAL_TO_INTEGER)) || \
    (DEST == 32 && (defined DECIMAL_TO_DECIMAL || defined INTEGER_TO_DECIMAL))
#include "decimal32.h"
#endif

#define DFP_EXCEPTIONS_ENABLED 1

#define DFP_IEEE_FLAGS(status) (					\
      (((status) & DEC_IEEE_854_Division_by_zero) ? FE_DIVBYZERO : 0) |	\
      (((status) & DEC_IEEE_854_Inexact) ? FE_INEXACT : 0) |		\
      (((status) & DEC_IEEE_854_Invalid_operation) ? FE_INVALID : 0) |	\
      (((status) & DEC_IEEE_854_Overflow) ? FE_OVERFLOW : 0) |		\
      (((status) & DEC_IEEE_854_Underflow) ? FE_UNDERFLOW : 0))

#include <fenv_libdfp.h>

#ifdef fegetenv_register
# define DFP_TEST_EXCEPTIONS(status)	({	\
	fenv_union_t u; 			\
	u.fenv = fegetenv_register(); 		\
	u.l & (status);				\
	})
# define DFP_CLEAR_EXCEPTIONS(status)	{	\
	fenv_union_t u;				\
	u.fenv = fegetenv_register();		\
	u.l &= ~status;				\
	fesetenv_register(u.fenv);		\
	}
#else
# include <fenv.h>
/* Non-register targets might want to use the standard functions.
 * Note that it is necessary to include these symbols in libdfp
 * to avoid libm dependencies.  */
# define DFP_TEST_EXCEPTIONS(status)	fetestexcept (status)
# define DFP_CLEAR_EXCEPTIONS(status)	feclearexcept (status)
#endif

#define DFP_HANDLE_EXCEPTIONS(status)	feraiseexcept(status)

#define CONVERT_WRAPPER(...)			\
DEST_TYPE					\
PREFIXED_FUNCTION_NAME (SRC_TYPE a)		\
{						\
	DEST_TYPE result = DEST_LITERAL(0.0);	\
						\
	switch (CLASSIFY (a)) {			\
		case FP_ZERO:			\
			result = SIGNBIT(a) ?   \
			  DEST_LITERAL(-0.0) :  \
			  DEST_LITERAL(0.0);	\
			break;			\
		case FP_INFINITE: 		\
			result = SIGNBIT(a) ? 	\
			  -DEST_INFINITY : 	\
			  DEST_INFINITY;	\
			break;			\
		case FP_NAN:			\
			result = DEST_NAN;	\
			break;			\
		default: {			\
			__VA_ARGS__		\
			}			\
	}					\
	return result;				\
}

// A hack for GCC12 to ensure we call the "correct" libgcc function.
// See GCC PR10423.
#if defined (__powerpc64__) && __LDBL_MANT_DIG__ == 113
extern __ibm128 __floatditf(long long);
#define TOIBM128(x) __floatditf(x)
#else
#define TOIBM128(x) (x)
#endif