summaryrefslogtreecommitdiff
path: root/Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c
diff options
context:
space:
mode:
Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c')
-rw-r--r--Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c36
1 files changed, 11 insertions, 25 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c b/Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c
index ed1191d53c2..11bf3a1d34b 100644
--- a/Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c
+++ b/Build/source/libs/mpfr/mpfr-src/src/mul_2ui.c
@@ -1,6 +1,6 @@
/* mpfr_mul_2ui -- multiply a floating-point number by a power of two
-Copyright 1999, 2001-2019 Free Software Foundation, Inc.
+Copyright 1999, 2001-2020 Free Software Foundation, Inc.
Contributed by the AriC and Caramba projects, INRIA.
This file is part of the GNU MPFR Library.
@@ -35,31 +35,17 @@ mpfr_mul_2ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int n, mpfr_rnd_t rnd_mod
inexact = (y != x) ? mpfr_set (y, x, rnd_mode) : 0;
- if (MPFR_LIKELY( MPFR_IS_PURE_FP(y)) )
+ if (MPFR_LIKELY (MPFR_IS_PURE_FP (y)))
{
- /* n will have to be casted to long to make sure that the addition
- and subtraction below (for overflow detection) are signed */
- while (MPFR_UNLIKELY(n > LONG_MAX))
- {
- int inex2;
-
- n -= LONG_MAX;
- inex2 = mpfr_mul_2ui(y, y, LONG_MAX, rnd_mode);
- if (inex2)
- return inex2; /* overflow */
- }
-
- /* MPFR_EMIN_MIN + (long) n is signed and doesn't lead to an overflow;
- the first test useful so that the real test can't lead to an
- overflow. */
- {
- mpfr_exp_t exp = MPFR_GET_EXP (y);
- if (MPFR_UNLIKELY( __gmpfr_emax < MPFR_EMIN_MIN + (long) n ||
- exp > __gmpfr_emax - (long) n))
- return mpfr_overflow (y, rnd_mode, MPFR_SIGN(y));
-
- MPFR_SET_EXP (y, exp + (long) n);
- }
+ mpfr_exp_t exp = MPFR_GET_EXP (y);
+ mpfr_exp_t diffexp;
+
+ diffexp = __gmpfr_emax - exp; /* diff of two valid exponents */
+ if (MPFR_UNLIKELY (n > diffexp)) /* exp + n > emax */
+ return mpfr_overflow (y, rnd_mode, MPFR_SIGN (y));
+ /* Now, 0 <= n <= diffexp, thus n fits in a mpfr_exp_t,
+ and exp + n <= emax (no integer overflow). */
+ MPFR_SET_EXP (y, exp + (mpfr_exp_t) n);
}
return inexact;