diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mpfr-impl.h | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/src/mpfr-impl.h b/src/mpfr-impl.h index dee42509f..188b72246 100644 --- a/src/mpfr-impl.h +++ b/src/mpfr-impl.h @@ -647,14 +647,23 @@ union ieee_double_decimal64 { double d; _Decimal64 d64; }; ******************************************************/ /* In the following macro, p is usually a mpfr_prec_t, but this macro - works with other integer types (without integer overflow). */ + works with other integer types (without integer overflow). Checking + that p >= 1 in debug mode is useful here because this macro can be + used on a computed precision (in particular, this formula does not + work for a degenerate case p = 0, and could give different results + on different platforms). But let us not use an assertion checking + in the MPFR_LAST_LIMB() and MPFR_LIMB_SIZE() macros below to avoid + too much expansion for assertions (in practice, this should be a + problem just when testing MPFR with the --enable-assert configure + option and the -ansi -pedantic-errors gcc compiler flags). */ #define MPFR_PREC2LIMBS(p) \ - (MPFR_ASSERTD (p >= 1), ((p) - 1) / GMP_NUMB_BITS + 1) + (MPFR_ASSERTD ((p) >= 1), ((p) - 1) / GMP_NUMB_BITS + 1) #define MPFR_PREC(x) ((x)->_mpfr_prec) #define MPFR_EXP(x) ((x)->_mpfr_exp) #define MPFR_MANT(x) ((x)->_mpfr_d) -#define MPFR_LIMB_SIZE(x) (MPFR_PREC2LIMBS (MPFR_PREC ((x)))) +#define MPFR_LAST_LIMB(x) ((MPFR_PREC (x) - 1) / GMP_NUMB_BITS) +#define MPFR_LIMB_SIZE(x) (MPFR_LAST_LIMB (x) + 1) /****************************************************** @@ -754,7 +763,8 @@ typedef intmax_t mpfr_eexp_t; #define MPFR_IS_FP(x) (!MPFR_IS_NAN(x) && !MPFR_IS_INF(x)) #define MPFR_IS_SINGULAR(x) (MPFR_EXP(x) <= MPFR_EXP_INF) #define MPFR_IS_PURE_FP(x) (!MPFR_IS_SINGULAR(x) && \ - (MPFR_ASSERTD (MPFR_MANT(x)[MPFR_LIMB_SIZE(x)-1] & MPFR_LIMB_HIGHBIT), 1)) + (MPFR_ASSERTD ((MPFR_MANT(x)[MPFR_LAST_LIMB(x)] \ + & MPFR_LIMB_HIGHBIT) != 0), 1)) #define MPFR_ARE_SINGULAR(x,y) \ (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)) || MPFR_UNLIKELY(MPFR_IS_SINGULAR(y))) @@ -1066,7 +1076,7 @@ extern unsigned char *mpfr_stack; /* Set a number to 1 (Fast) - It doesn't check if 1 is in the exponent range */ #define MPFR_SET_ONE(x) \ do { \ - mp_size_t _size = MPFR_LIMB_SIZE(x) - 1; \ + mp_size_t _size = MPFR_LAST_LIMB(x); \ MPFR_SET_POS(x); \ MPFR_EXP(x) = 1; \ MPN_ZERO ( MPFR_MANT(x), _size); \ |