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| author | Ian Lance Taylor <ian@gcc.gnu.org> | 2017-08-09 17:15:02 +0000 |
|---|---|---|
| committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2017-08-09 17:15:02 +0000 |
| commit | a171ac0380a22f992d9c57a4189ddfc834d0e022 (patch) | |
| tree | 154cca144f12a16ddd90a6311693784825b3485a | |
| parent | 0ca970cd53e8fb86462ae36fab068f3a8073bc86 (diff) | |
| download | gcc-a171ac0380a22f992d9c57a4189ddfc834d0e022.zip gcc-a171ac0380a22f992d9c57a4189ddfc834d0e022.tar.gz gcc-a171ac0380a22f992d9c57a4189ddfc834d0e022.tar.bz2 | |
compiler: handle >32bit exponent in Ldexp
Libgo's implementation of math.Ldexp declared the libc "ldexp" as
taking an 'int' exponent argument, which is not quite right for 64-bit
platforms (exp arg is always int32); this could yield incorrect
results for exponent values outside the range of Minint32/Maxint32.
Fix by upating the type for the libc version of ldexp, and adding
guards to screen for out-of-range exponents.
Fixes #21323.
Reviewed-on: https://go-review.googlesource.com/54250
From-SVN: r250992
| -rw-r--r-- | gcc/go/gofrontend/MERGE | 2 | ||||
| -rw-r--r-- | libgo/go/math/ldexp.go | 9 |
2 files changed, 8 insertions, 3 deletions
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index b86cb85..4fe569c 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -db685a1a9aa8b3b916dd6d1284895e01d73158e1 +5fd112e5c2968e94761c41519c451d789e23a92b The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/libgo/go/math/ldexp.go b/libgo/go/math/ldexp.go index 2898f5d..e91a090 100644 --- a/libgo/go/math/ldexp.go +++ b/libgo/go/math/ldexp.go @@ -13,10 +13,15 @@ package math // Ldexp(NaN, exp) = NaN //extern ldexp -func libc_ldexp(float64, int) float64 +func libc_ldexp(float64, int32) float64 func Ldexp(frac float64, exp int) float64 { - r := libc_ldexp(frac, exp) + if exp > MaxInt32 { + exp = MaxInt32 + } else if exp < MinInt32 { + exp = MinInt32 + } + r := libc_ldexp(frac, int32(exp)) return r } |