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-rw-r--r--base/rand_util.cc6
1 files changed, 5 insertions, 1 deletions
diff --git a/base/rand_util.cc b/base/rand_util.cc
index a71bb0c..b823fa0 100644
--- a/base/rand_util.cc
+++ b/base/rand_util.cc
@@ -24,6 +24,10 @@ int RandInt(int min, int max) {
}
double RandDouble() {
+ return BitsToOpenEndedUnitInterval(base::RandUint64());
+}
+
+double BitsToOpenEndedUnitInterval(uint64 bits) {
// We try to get maximum precision by masking out as many bits as will fit
// in the target type's mantissa, and raising it to an appropriate power to
// produce output in the range [0, 1). For IEEE 754 doubles, the mantissa
@@ -31,7 +35,7 @@ double RandDouble() {
COMPILE_ASSERT(std::numeric_limits<double>::radix == 2, otherwise_use_scalbn);
static const int kBits = std::numeric_limits<double>::digits;
- uint64 random_bits = base::RandUint64() & ((GG_UINT64_C(1) << kBits) - 1);
+ uint64 random_bits = bits & ((GG_UINT64_C(1) << kBits) - 1);
double result = ldexp(static_cast<double>(random_bits), -1 * kBits);
DCHECK_GE(result, 0.0);
DCHECK_LT(result, 1.0);