*----------------------------------------------------------------------------*/
static inline bool floatx80_invalid_encoding(floatx80 a)
{
+#if defined(TARGET_M68K)
+ /*-------------------------------------------------------------------------
+ | With m68k, the explicit integer bit can be zero in the case of:
+ | - zeros (exp == 0, mantissa == 0)
+ | - denormalized numbers (exp == 0, mantissa != 0)
+ | - unnormalized numbers (exp != 0, exp < 0x7FFF)
+ | - infinities (exp == 0x7FFF, mantissa == 0)
+ | - not-a-numbers (exp == 0x7FFF, mantissa != 0)
+ |
+ | For infinities and NaNs, the explicit integer bit can be either one or
+ | zero.
+ |
+ | The IEEE 754 standard does not define a zero integer bit. Such a number
+ | is an unnormalized number. Hardware does not directly support
+ | denormalized and unnormalized numbers, but implicitly supports them by
+ | trapping them as unimplemented data types, allowing efficient conversion
+ | in software.
+ |
+ | See "M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL",
+ | "1.6 FLOATING-POINT DATA TYPES"
+ *------------------------------------------------------------------------*/
+ return false;
+#else
return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
+#endif
}
#define floatx80_zero make_floatx80(0x0000, 0x0000000000000000LL)