diff options
| -rw-r--r-- | api/next/61716.txt | 7 | ||||
| -rw-r--r-- | src/math/rand/v2/rand.go | 26 | ||||
| -rw-r--r-- | src/math/rand/v2/rand_test.go | 2 |
3 files changed, 8 insertions, 27 deletions
diff --git a/api/next/61716.txt b/api/next/61716.txt index 353ad379d0..44d40ef1f3 100644 --- a/api/next/61716.txt +++ b/api/next/61716.txt @@ -31,9 +31,6 @@ pkg math/rand/v2, method (*Rand) Uint32() uint32 #61716 pkg math/rand/v2, method (*Rand) Uint64() uint64 #61716 pkg math/rand/v2, method (*Zipf) Uint64() uint64 #61716 pkg math/rand/v2, type Rand struct #61716 -pkg math/rand/v2, type Source interface { Int64 } #61716 -pkg math/rand/v2, type Source interface, Int64() int64 #61716 -pkg math/rand/v2, type Source64 interface { Int64, Uint64 } #61716 -pkg math/rand/v2, type Source64 interface, Int64() int64 #61716 -pkg math/rand/v2, type Source64 interface, Uint64() uint64 #61716 +pkg math/rand/v2, type Source interface { Uint64 } #61716 +pkg math/rand/v2, type Source interface, Uint64() uint64 #61716 pkg math/rand/v2, type Zipf struct #61716 diff --git a/src/math/rand/v2/rand.go b/src/math/rand/v2/rand.go index c9d1ec11df..337a6aa5a0 100644 --- a/src/math/rand/v2/rand.go +++ b/src/math/rand/v2/rand.go @@ -21,22 +21,11 @@ import ( _ "unsafe" // for go:linkname ) -// A Source represents a source of uniformly-distributed -// pseudo-random int64 values in the range [0, 1<<63). +// A Source is a source of uniformly-distributed +// pseudo-random uint64 values in the range [0, 1<<64). // // A Source is not safe for concurrent use by multiple goroutines. type Source interface { - Int64() int64 -} - -// A Source64 is a Source that can also generate -// uniformly-distributed pseudo-random uint64 values in -// the range [0, 1<<64) directly. -// If a Rand r's underlying Source s implements Source64, -// then r.Uint64 returns the result of one call to s.Uint64 -// instead of making two calls to s.Int64. -type Source64 interface { - Source Uint64() uint64 } @@ -57,28 +46,23 @@ func newSource(seed int64) *rngSource { // A Rand is a source of random numbers. type Rand struct { src Source - s64 Source64 // non-nil if src is source64 } // New returns a new Rand that uses random values from src // to generate other random values. func New(src Source) *Rand { - s64, _ := src.(Source64) - return &Rand{src: src, s64: s64} + return &Rand{src: src} } // Int64 returns a non-negative pseudo-random 63-bit integer as an int64. -func (r *Rand) Int64() int64 { return r.src.Int64() } +func (r *Rand) Int64() int64 { return int64(r.src.Uint64() &^ (1 << 63)) } // Uint32 returns a pseudo-random 32-bit value as a uint32. func (r *Rand) Uint32() uint32 { return uint32(r.Int64() >> 31) } // Uint64 returns a pseudo-random 64-bit value as a uint64. func (r *Rand) Uint64() uint64 { - if r.s64 != nil { - return r.s64.Uint64() - } - return uint64(r.Int64())>>31 | uint64(r.Int64())<<32 + return r.src.Uint64() } // Int32 returns a non-negative pseudo-random 31-bit integer as an int32. diff --git a/src/math/rand/v2/rand_test.go b/src/math/rand/v2/rand_test.go index ab7fb56796..6385497575 100644 --- a/src/math/rand/v2/rand_test.go +++ b/src/math/rand/v2/rand_test.go @@ -481,7 +481,7 @@ func testRand() *Rand { } func BenchmarkSourceUint64(b *testing.B) { - s := NewSource(1).(Source64) + s := NewSource(1) var t uint64 for n := b.N; n > 0; n-- { t += s.Uint64() |