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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/ui_sub.c')
-rw-r--r--Build/source/libs/mpfr/mpfr-src/src/ui_sub.c64
1 files changed, 34 insertions, 30 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c b/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c
index 0ef7917c389..d5fae6e1c13 100644
--- a/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c
+++ b/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c
@@ -31,48 +31,52 @@ mpfr_ui_sub (mpfr_ptr y, unsigned long int u, mpfr_srcptr x, mpfr_rnd_t rnd_mode
u, mpfr_get_prec(x), mpfr_log_prec, x, rnd_mode),
("y[%Pu]=%.*Rg", mpfr_get_prec(y), mpfr_log_prec, y));
+ /* (unsigned long) 0 is assumed to be a real 0 (unsigned) */
if (MPFR_UNLIKELY (u == 0))
return mpfr_neg (y, x, rnd_mode);
- if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)))
+ if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x)))
{
- if (MPFR_IS_NAN(x))
+ if (MPFR_IS_NAN (x))
{
- MPFR_SET_NAN(y);
+ MPFR_SET_NAN (y);
MPFR_RET_NAN;
}
- else if (MPFR_IS_INF(x))
+ if (MPFR_IS_INF (x))
{
/* u - Inf = -Inf and u - -Inf = +Inf */
- MPFR_SET_INF(y);
- MPFR_SET_OPPOSITE_SIGN(y,x);
- MPFR_RET(0); /* +/-infinity is exact */
+ MPFR_SET_INF (y);
+ MPFR_SET_OPPOSITE_SIGN (y, x);
+ MPFR_RET (0); /* +/-infinity is exact */
}
- else /* x is zero */
- /* u - 0 = u */
- return mpfr_set_ui(y, u, rnd_mode);
+ MPFR_ASSERTD (MPFR_IS_ZERO (x) && u != 0);
+ /* Note: the fact that u != 0 is important due to signed zeros. */
+ /* u - 0 = u */
+ return mpfr_set_ui (y, u, rnd_mode);
}
- else
- {
- mpfr_t uu;
- mp_limb_t up[1];
- int cnt;
- int inex;
- MPFR_SAVE_EXPO_DECL (expo);
+ /* Main code */
+ {
+ mpfr_t uu;
+ mp_limb_t up[1];
+ int cnt;
+ int inex;
+ MPFR_SAVE_EXPO_DECL (expo);
- MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS);
- MPFR_ASSERTN(u == (mp_limb_t) u);
- count_leading_zeros (cnt, (mp_limb_t) u);
- up[0] = (mp_limb_t) u << cnt;
+ MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS);
+ MPFR_STAT_STATIC_ASSERT (MPFR_LIMB_MAX >= ULONG_MAX);
+ /* So, u fits in a mp_limb_t, which justifies the casts below. */
+ MPFR_ASSERTD (u != 0);
+ count_leading_zeros (cnt, (mp_limb_t) u);
+ up[0] = (mp_limb_t) u << cnt;
- /* Optimization note: Exponent save/restore operations may be
- removed if mpfr_sub works even when uu is out-of-range. */
- MPFR_SAVE_EXPO_MARK (expo);
- MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
- inex = mpfr_sub (y, uu, x, rnd_mode);
- MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, __gmpfr_flags);
- MPFR_SAVE_EXPO_FREE (expo);
- return mpfr_check_range(y, inex, rnd_mode);
- }
+ /* Optimization note: Exponent save/restore operations may be
+ removed if mpfr_sub works even when uu is out-of-range. */
+ MPFR_SAVE_EXPO_MARK (expo);
+ MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
+ inex = mpfr_sub (y, uu, x, rnd_mode);
+ MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, __gmpfr_flags);
+ MPFR_SAVE_EXPO_FREE (expo);
+ return mpfr_check_range (y, inex, rnd_mode);
+ }
}