cosmopolitan/third_party/duktape/duk_dblunion.h

425 lines
17 KiB
C

/*
* Union to access IEEE double memory representation, indexes for double
* memory representation, and some macros for double manipulation.
*
* Also used by packed duk_tval. Use a union for bit manipulation to
* minimize aliasing issues in practice. The C99 standard does not
* guarantee that this should work, but it's a very widely supported
* practice for low level manipulation.
*
* IEEE double format summary:
*
* seeeeeee eeeeffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
* A B C D E F G H
*
* s sign bit
* eee... exponent field
* fff... fraction
*
* See http://en.wikipedia.org/wiki/Double_precision_floating-point_format.
*
* NaNs are represented as exponent 0x7ff and mantissa != 0. The NaN is a
* signaling NaN when the highest bit of the mantissa is zero, and a quiet
* NaN when the highest bit is set.
*
* At least three memory layouts are relevant here:
*
* A B C D E F G H Big endian (e.g. 68k) DUK_USE_DOUBLE_BE
* H G F E D C B A Little endian (e.g. x86) DUK_USE_DOUBLE_LE
* D C B A H G F E Mixed endian (e.g. ARM FPA) DUK_USE_DOUBLE_ME
*
* Legacy ARM (FPA) is a special case: ARM double values are in mixed
* endian format while ARM duk_uint64_t values are in standard little endian
* format (H G F E D C B A). When a double is read as a duk_uint64_t
* from memory, the register will contain the (logical) value
* E F G H A B C D. This requires some special handling below.
* See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0056d/Bcfhgcgd.html.
*
* Indexes of various types (8-bit, 16-bit, 32-bit) in memory relative to
* the logical (big endian) order:
*
* byte order duk_uint8_t duk_uint16_t duk_uint32_t
* BE 01234567 0123 01
* LE 76543210 3210 10
* ME (ARM) 32107654 1032 01
*
* Some processors may alter NaN values in a floating point load+store.
* For instance, on X86 a FLD + FSTP may convert a signaling NaN to a
* quiet one. This is catastrophic when NaN space is used in packed
* duk_tval values. See: misc/clang_aliasing.c.
*/
#if !defined(DUK_DBLUNION_H_INCLUDED)
#define DUK_DBLUNION_H_INCLUDED
/*
* Union for accessing double parts, also serves as packed duk_tval
*/
union duk_double_union {
double d;
float f[2];
#if defined(DUK_USE_64BIT_OPS)
duk_uint64_t ull[1];
#endif
duk_uint32_t ui[2];
duk_uint16_t us[4];
duk_uint8_t uc[8];
#if defined(DUK_USE_PACKED_TVAL)
void *vp[2]; /* used by packed duk_tval, assumes sizeof(void *) == 4 */
#endif
};
typedef union duk_double_union duk_double_union;
/*
* Indexes of various types with respect to big endian (logical) layout
*/
#if defined(DUK_USE_DOUBLE_LE)
#if defined(DUK_USE_64BIT_OPS)
#define DUK_DBL_IDX_ULL0 0
#endif
#define DUK_DBL_IDX_UI0 1
#define DUK_DBL_IDX_UI1 0
#define DUK_DBL_IDX_US0 3
#define DUK_DBL_IDX_US1 2
#define DUK_DBL_IDX_US2 1
#define DUK_DBL_IDX_US3 0
#define DUK_DBL_IDX_UC0 7
#define DUK_DBL_IDX_UC1 6
#define DUK_DBL_IDX_UC2 5
#define DUK_DBL_IDX_UC3 4
#define DUK_DBL_IDX_UC4 3
#define DUK_DBL_IDX_UC5 2
#define DUK_DBL_IDX_UC6 1
#define DUK_DBL_IDX_UC7 0
#define DUK_DBL_IDX_VP0 DUK_DBL_IDX_UI0 /* packed tval */
#define DUK_DBL_IDX_VP1 DUK_DBL_IDX_UI1 /* packed tval */
#elif defined(DUK_USE_DOUBLE_BE)
#if defined(DUK_USE_64BIT_OPS)
#define DUK_DBL_IDX_ULL0 0
#endif
#define DUK_DBL_IDX_UI0 0
#define DUK_DBL_IDX_UI1 1
#define DUK_DBL_IDX_US0 0
#define DUK_DBL_IDX_US1 1
#define DUK_DBL_IDX_US2 2
#define DUK_DBL_IDX_US3 3
#define DUK_DBL_IDX_UC0 0
#define DUK_DBL_IDX_UC1 1
#define DUK_DBL_IDX_UC2 2
#define DUK_DBL_IDX_UC3 3
#define DUK_DBL_IDX_UC4 4
#define DUK_DBL_IDX_UC5 5
#define DUK_DBL_IDX_UC6 6
#define DUK_DBL_IDX_UC7 7
#define DUK_DBL_IDX_VP0 DUK_DBL_IDX_UI0 /* packed tval */
#define DUK_DBL_IDX_VP1 DUK_DBL_IDX_UI1 /* packed tval */
#elif defined(DUK_USE_DOUBLE_ME)
#if defined(DUK_USE_64BIT_OPS)
#define DUK_DBL_IDX_ULL0 0 /* not directly applicable, byte order differs from a double */
#endif
#define DUK_DBL_IDX_UI0 0
#define DUK_DBL_IDX_UI1 1
#define DUK_DBL_IDX_US0 1
#define DUK_DBL_IDX_US1 0
#define DUK_DBL_IDX_US2 3
#define DUK_DBL_IDX_US3 2
#define DUK_DBL_IDX_UC0 3
#define DUK_DBL_IDX_UC1 2
#define DUK_DBL_IDX_UC2 1
#define DUK_DBL_IDX_UC3 0
#define DUK_DBL_IDX_UC4 7
#define DUK_DBL_IDX_UC5 6
#define DUK_DBL_IDX_UC6 5
#define DUK_DBL_IDX_UC7 4
#define DUK_DBL_IDX_VP0 DUK_DBL_IDX_UI0 /* packed tval */
#define DUK_DBL_IDX_VP1 DUK_DBL_IDX_UI1 /* packed tval */
#else
#error internal error
#endif
/*
* Helper macros for reading/writing memory representation parts, used
* by duk_numconv.c and duk_tval.h.
*/
#define DUK_DBLUNION_SET_DOUBLE(u,v) do { \
(u)->d = (v); \
} while (0)
#define DUK_DBLUNION_SET_HIGH32(u,v) do { \
(u)->ui[DUK_DBL_IDX_UI0] = (duk_uint32_t) (v); \
} while (0)
#if defined(DUK_USE_64BIT_OPS)
#if defined(DUK_USE_DOUBLE_ME)
#define DUK_DBLUNION_SET_HIGH32_ZERO_LOW32(u,v) do { \
(u)->ull[DUK_DBL_IDX_ULL0] = (duk_uint64_t) (v); \
} while (0)
#else
#define DUK_DBLUNION_SET_HIGH32_ZERO_LOW32(u,v) do { \
(u)->ull[DUK_DBL_IDX_ULL0] = ((duk_uint64_t) (v)) << 32; \
} while (0)
#endif
#else /* DUK_USE_64BIT_OPS */
#define DUK_DBLUNION_SET_HIGH32_ZERO_LOW32(u,v) do { \
(u)->ui[DUK_DBL_IDX_UI0] = (duk_uint32_t) (v); \
(u)->ui[DUK_DBL_IDX_UI1] = (duk_uint32_t) 0; \
} while (0)
#endif /* DUK_USE_64BIT_OPS */
#define DUK_DBLUNION_SET_LOW32(u,v) do { \
(u)->ui[DUK_DBL_IDX_UI1] = (duk_uint32_t) (v); \
} while (0)
#define DUK_DBLUNION_GET_DOUBLE(u) ((u)->d)
#define DUK_DBLUNION_GET_HIGH32(u) ((u)->ui[DUK_DBL_IDX_UI0])
#define DUK_DBLUNION_GET_LOW32(u) ((u)->ui[DUK_DBL_IDX_UI1])
#if defined(DUK_USE_64BIT_OPS)
#if defined(DUK_USE_DOUBLE_ME)
#define DUK_DBLUNION_SET_UINT64(u,v) do { \
(u)->ui[DUK_DBL_IDX_UI0] = (duk_uint32_t) ((v) >> 32); \
(u)->ui[DUK_DBL_IDX_UI1] = (duk_uint32_t) (v); \
} while (0)
#define DUK_DBLUNION_GET_UINT64(u) \
((((duk_uint64_t) (u)->ui[DUK_DBL_IDX_UI0]) << 32) | \
((duk_uint64_t) (u)->ui[DUK_DBL_IDX_UI1]))
#else
#define DUK_DBLUNION_SET_UINT64(u,v) do { \
(u)->ull[DUK_DBL_IDX_ULL0] = (duk_uint64_t) (v); \
} while (0)
#define DUK_DBLUNION_GET_UINT64(u) ((u)->ull[DUK_DBL_IDX_ULL0])
#endif
#define DUK_DBLUNION_SET_INT64(u,v) DUK_DBLUNION_SET_UINT64((u), (duk_uint64_t) (v))
#define DUK_DBLUNION_GET_INT64(u) ((duk_int64_t) DUK_DBLUNION_GET_UINT64((u)))
#endif /* DUK_USE_64BIT_OPS */
/*
* Double NaN manipulation macros related to NaN normalization needed when
* using the packed duk_tval representation. NaN normalization is necessary
* to keep double values compatible with the duk_tval format.
*
* When packed duk_tval is used, the NaN space is used to store pointers
* and other tagged values in addition to NaNs. Actual NaNs are normalized
* to a specific quiet NaN. The macros below are used by the implementation
* to check and normalize NaN values when they might be created. The macros
* are essentially NOPs when the non-packed duk_tval representation is used.
*
* A FULL check is exact and checks all bits. A NOTFULL check is used by
* the packed duk_tval and works correctly for all NaNs except those that
* begin with 0x7ff0. Since the 'normalized NaN' values used with packed
* duk_tval begin with 0x7ff8, the partial check is reliable when packed
* duk_tval is used. The 0x7ff8 prefix means the normalized NaN will be a
* quiet NaN regardless of its remaining lower bits.
*
* The ME variant below is specifically for ARM byte order, which has the
* feature that while doubles have a mixed byte order (32107654), unsigned
* long long values has a little endian byte order (76543210). When writing
* a logical double value through a ULL pointer, the 32-bit words need to be
* swapped; hence the #if defined()s below for ULL writes with DUK_USE_DOUBLE_ME.
* This is not full ARM support but suffices for some environments.
*/
#if defined(DUK_USE_64BIT_OPS)
#if defined(DUK_USE_DOUBLE_ME)
/* Macros for 64-bit ops + mixed endian doubles. */
#define DUK__DBLUNION_SET_NAN_FULL(u) do { \
(u)->ull[DUK_DBL_IDX_ULL0] = DUK_U64_CONSTANT(0x000000007ff80000); \
} while (0)
#define DUK__DBLUNION_IS_NAN_FULL(u) \
((((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0x000000007ff00000)) == DUK_U64_CONSTANT(0x000000007ff00000)) && \
((((u)->ull[DUK_DBL_IDX_ULL0]) & DUK_U64_CONSTANT(0xffffffff000fffff)) != 0))
#define DUK__DBLUNION_IS_NORMALIZED_NAN_FULL(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x000000007ff80000))
#define DUK__DBLUNION_IS_ANYINF(u) \
(((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0xffffffff7fffffff)) == DUK_U64_CONSTANT(0x000000007ff00000))
#define DUK__DBLUNION_IS_POSINF(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x000000007ff00000))
#define DUK__DBLUNION_IS_NEGINF(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x00000000fff00000))
#define DUK__DBLUNION_IS_ANYZERO(u) \
(((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0xffffffff7fffffff)) == DUK_U64_CONSTANT(0x0000000000000000))
#define DUK__DBLUNION_IS_POSZERO(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x0000000000000000))
#define DUK__DBLUNION_IS_NEGZERO(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x0000000080000000))
#else
/* Macros for 64-bit ops + big/little endian doubles. */
#define DUK__DBLUNION_SET_NAN_FULL(u) do { \
(u)->ull[DUK_DBL_IDX_ULL0] = DUK_U64_CONSTANT(0x7ff8000000000000); \
} while (0)
#define DUK__DBLUNION_IS_NAN_FULL(u) \
((((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0x7ff0000000000000)) == DUK_U64_CONSTANT(0x7ff0000000000000)) && \
((((u)->ull[DUK_DBL_IDX_ULL0]) & DUK_U64_CONSTANT(0x000fffffffffffff)) != 0))
#define DUK__DBLUNION_IS_NORMALIZED_NAN_FULL(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x7ff8000000000000))
#define DUK__DBLUNION_IS_ANYINF(u) \
(((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0x7fffffffffffffff)) == DUK_U64_CONSTANT(0x7ff0000000000000))
#define DUK__DBLUNION_IS_POSINF(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x7ff0000000000000))
#define DUK__DBLUNION_IS_NEGINF(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0xfff0000000000000))
#define DUK__DBLUNION_IS_ANYZERO(u) \
(((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0x7fffffffffffffff)) == DUK_U64_CONSTANT(0x0000000000000000))
#define DUK__DBLUNION_IS_POSZERO(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x0000000000000000))
#define DUK__DBLUNION_IS_NEGZERO(u) \
((u)->ull[DUK_DBL_IDX_ULL0] == DUK_U64_CONSTANT(0x8000000000000000))
#endif
#else /* DUK_USE_64BIT_OPS */
/* Macros for no 64-bit ops, any endianness. */
#define DUK__DBLUNION_SET_NAN_FULL(u) do { \
(u)->ui[DUK_DBL_IDX_UI0] = (duk_uint32_t) 0x7ff80000UL; \
(u)->ui[DUK_DBL_IDX_UI1] = (duk_uint32_t) 0x00000000UL; \
} while (0)
#define DUK__DBLUNION_IS_NAN_FULL(u) \
((((u)->ui[DUK_DBL_IDX_UI0] & 0x7ff00000UL) == 0x7ff00000UL) && \
(((u)->ui[DUK_DBL_IDX_UI0] & 0x000fffffUL) != 0 || \
(u)->ui[DUK_DBL_IDX_UI1] != 0))
#define DUK__DBLUNION_IS_NORMALIZED_NAN_FULL(u) \
(((u)->ui[DUK_DBL_IDX_UI0] == 0x7ff80000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#define DUK__DBLUNION_IS_ANYINF(u) \
((((u)->ui[DUK_DBL_IDX_UI0] & 0x7fffffffUL) == 0x7ff00000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#define DUK__DBLUNION_IS_POSINF(u) \
(((u)->ui[DUK_DBL_IDX_UI0] == 0x7ff00000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#define DUK__DBLUNION_IS_NEGINF(u) \
(((u)->ui[DUK_DBL_IDX_UI0] == 0xfff00000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#define DUK__DBLUNION_IS_ANYZERO(u) \
((((u)->ui[DUK_DBL_IDX_UI0] & 0x7fffffffUL) == 0x00000000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#define DUK__DBLUNION_IS_POSZERO(u) \
(((u)->ui[DUK_DBL_IDX_UI0] == 0x00000000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#define DUK__DBLUNION_IS_NEGZERO(u) \
(((u)->ui[DUK_DBL_IDX_UI0] == 0x80000000UL) && \
((u)->ui[DUK_DBL_IDX_UI1] == 0x00000000UL))
#endif /* DUK_USE_64BIT_OPS */
#define DUK__DBLUNION_SET_NAN_NOTFULL(u) do { \
(u)->us[DUK_DBL_IDX_US0] = 0x7ff8UL; \
} while (0)
#define DUK__DBLUNION_IS_NAN_NOTFULL(u) \
/* E == 0x7ff, topmost four bits of F != 0 => assume NaN */ \
((((u)->us[DUK_DBL_IDX_US0] & 0x7ff0UL) == 0x7ff0UL) && \
(((u)->us[DUK_DBL_IDX_US0] & 0x000fUL) != 0x0000UL))
#define DUK__DBLUNION_IS_NORMALIZED_NAN_NOTFULL(u) \
/* E == 0x7ff, F == 8 => normalized NaN */ \
((u)->us[DUK_DBL_IDX_US0] == 0x7ff8UL)
#define DUK__DBLUNION_NORMALIZE_NAN_CHECK_FULL(u) do { \
if (DUK__DBLUNION_IS_NAN_FULL((u))) { \
DUK__DBLUNION_SET_NAN_FULL((u)); \
} \
} while (0)
#define DUK__DBLUNION_NORMALIZE_NAN_CHECK_NOTFULL(u) do { \
if (DUK__DBLUNION_IS_NAN_NOTFULL((u))) { \
DUK__DBLUNION_SET_NAN_NOTFULL((u)); \
} \
} while (0)
/* Concrete macros for NaN handling used by the implementation internals.
* Chosen so that they match the duk_tval representation: with a packed
* duk_tval, ensure NaNs are properly normalized; with a non-packed duk_tval
* these are essentially NOPs.
*/
#if defined(DUK_USE_PACKED_TVAL)
#if defined(DUK_USE_FULL_TVAL)
#define DUK_DBLUNION_NORMALIZE_NAN_CHECK(u) DUK__DBLUNION_NORMALIZE_NAN_CHECK_FULL((u))
#define DUK_DBLUNION_IS_NAN(u) DUK__DBLUNION_IS_NAN_FULL((u))
#define DUK_DBLUNION_IS_NORMALIZED_NAN(u) DUK__DBLUNION_IS_NORMALIZED_NAN_FULL((u))
#define DUK_DBLUNION_SET_NAN(d) DUK__DBLUNION_SET_NAN_FULL((d))
#else
#define DUK_DBLUNION_NORMALIZE_NAN_CHECK(u) DUK__DBLUNION_NORMALIZE_NAN_CHECK_NOTFULL((u))
#define DUK_DBLUNION_IS_NAN(u) DUK__DBLUNION_IS_NAN_NOTFULL((u))
#define DUK_DBLUNION_IS_NORMALIZED_NAN(u) DUK__DBLUNION_IS_NORMALIZED_NAN_NOTFULL((u))
#define DUK_DBLUNION_SET_NAN(d) DUK__DBLUNION_SET_NAN_NOTFULL((d))
#endif
#define DUK_DBLUNION_IS_NORMALIZED(u) \
(!DUK_DBLUNION_IS_NAN((u)) || /* either not a NaN */ \
DUK_DBLUNION_IS_NORMALIZED_NAN((u))) /* or is a normalized NaN */
#else /* DUK_USE_PACKED_TVAL */
#define DUK_DBLUNION_NORMALIZE_NAN_CHECK(u) /* nop: no need to normalize */
#define DUK_DBLUNION_IS_NAN(u) DUK__DBLUNION_IS_NAN_FULL((u)) /* (DUK_ISNAN((u)->d)) */
#define DUK_DBLUNION_IS_NORMALIZED_NAN(u) DUK__DBLUNION_IS_NAN_FULL((u)) /* (DUK_ISNAN((u)->d)) */
#define DUK_DBLUNION_IS_NORMALIZED(u) 1 /* all doubles are considered normalized */
#define DUK_DBLUNION_SET_NAN(u) do { \
/* in non-packed representation we don't care about which NaN is used */ \
(u)->d = DUK_DOUBLE_NAN; \
} while (0)
#endif /* DUK_USE_PACKED_TVAL */
#define DUK_DBLUNION_IS_ANYINF(u) DUK__DBLUNION_IS_ANYINF((u))
#define DUK_DBLUNION_IS_POSINF(u) DUK__DBLUNION_IS_POSINF((u))
#define DUK_DBLUNION_IS_NEGINF(u) DUK__DBLUNION_IS_NEGINF((u))
#define DUK_DBLUNION_IS_ANYZERO(u) DUK__DBLUNION_IS_ANYZERO((u))
#define DUK_DBLUNION_IS_POSZERO(u) DUK__DBLUNION_IS_POSZERO((u))
#define DUK_DBLUNION_IS_NEGZERO(u) DUK__DBLUNION_IS_NEGZERO((u))
/* XXX: native 64-bit byteswaps when available */
/* 64-bit byteswap, same operation independent of target endianness. */
#define DUK_DBLUNION_BSWAP64(u) do { \
duk_uint32_t duk__bswaptmp1, duk__bswaptmp2; \
duk__bswaptmp1 = (u)->ui[0]; \
duk__bswaptmp2 = (u)->ui[1]; \
duk__bswaptmp1 = DUK_BSWAP32(duk__bswaptmp1); \
duk__bswaptmp2 = DUK_BSWAP32(duk__bswaptmp2); \
(u)->ui[0] = duk__bswaptmp2; \
(u)->ui[1] = duk__bswaptmp1; \
} while (0)
/* Byteswap an IEEE double in the duk_double_union from host to network
* order. For a big endian target this is a no-op.
*/
#if defined(DUK_USE_DOUBLE_LE)
#define DUK_DBLUNION_DOUBLE_HTON(u) do { \
duk_uint32_t duk__bswaptmp1, duk__bswaptmp2; \
duk__bswaptmp1 = (u)->ui[0]; \
duk__bswaptmp2 = (u)->ui[1]; \
duk__bswaptmp1 = DUK_BSWAP32(duk__bswaptmp1); \
duk__bswaptmp2 = DUK_BSWAP32(duk__bswaptmp2); \
(u)->ui[0] = duk__bswaptmp2; \
(u)->ui[1] = duk__bswaptmp1; \
} while (0)
#elif defined(DUK_USE_DOUBLE_ME)
#define DUK_DBLUNION_DOUBLE_HTON(u) do { \
duk_uint32_t duk__bswaptmp1, duk__bswaptmp2; \
duk__bswaptmp1 = (u)->ui[0]; \
duk__bswaptmp2 = (u)->ui[1]; \
duk__bswaptmp1 = DUK_BSWAP32(duk__bswaptmp1); \
duk__bswaptmp2 = DUK_BSWAP32(duk__bswaptmp2); \
(u)->ui[0] = duk__bswaptmp1; \
(u)->ui[1] = duk__bswaptmp2; \
} while (0)
#elif defined(DUK_USE_DOUBLE_BE)
#define DUK_DBLUNION_DOUBLE_HTON(u) do { } while (0)
#else
#error internal error, double endianness insane
#endif
/* Reverse operation is the same. */
#define DUK_DBLUNION_DOUBLE_NTOH(u) DUK_DBLUNION_DOUBLE_HTON((u))
/* Some sign bit helpers. */
#if defined(DUK_USE_64BIT_OPS)
#define DUK_DBLUNION_HAS_SIGNBIT(u) (((u)->ull[DUK_DBL_IDX_ULL0] & DUK_U64_CONSTANT(0x8000000000000000)) != 0)
#define DUK_DBLUNION_GET_SIGNBIT(u) (((u)->ull[DUK_DBL_IDX_ULL0] >> 63U))
#else
#define DUK_DBLUNION_HAS_SIGNBIT(u) (((u)->ui[DUK_DBL_IDX_UI0] & 0x80000000UL) != 0)
#define DUK_DBLUNION_GET_SIGNBIT(u) (((u)->ui[DUK_DBL_IDX_UI0] >> 31U))
#endif
#endif /* DUK_DBLUNION_H_INCLUDED */