diff options
Diffstat (limited to 'src/go/constant/value.go')
| -rw-r--r-- | src/go/constant/value.go | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/src/go/constant/value.go b/src/go/constant/value.go index 116c7575d9..4a89ef3b94 100644 --- a/src/go/constant/value.go +++ b/src/go/constant/value.go @@ -17,6 +17,7 @@ import ( "go/token" "math" "math/big" + "math/bits" "strconv" "strings" "sync" @@ -610,7 +611,11 @@ func Make(x interface{}) Value { func BitLen(x Value) int { switch x := x.(type) { case int64Val: - return i64toi(x).val.BitLen() + u := uint64(x) + if x < 0 { + u = uint64(-x) + } + return 64 - bits.LeadingZeros64(u) case intVal: return x.val.BitLen() case unknownVal: @@ -1018,52 +1023,55 @@ func match(x, y Value) (_, _ Value) { } // ord(x) <= ord(y) - switch x := x.(type) { + // Prefer to return the original x and y arguments when possible, + // to avoid unnecessary heap allocations. + + switch x1 := x.(type) { case boolVal, *stringVal, complexVal: return x, y case int64Val: - switch y := y.(type) { + switch y.(type) { case int64Val: return x, y case intVal: - return i64toi(x), y + return i64toi(x1), y case ratVal: - return i64tor(x), y + return i64tor(x1), y case floatVal: - return i64tof(x), y + return i64tof(x1), y case complexVal: - return vtoc(x), y + return vtoc(x1), y } case intVal: - switch y := y.(type) { + switch y.(type) { case intVal: return x, y case ratVal: - return itor(x), y + return itor(x1), y case floatVal: - return itof(x), y + return itof(x1), y case complexVal: - return vtoc(x), y + return vtoc(x1), y } case ratVal: - switch y := y.(type) { + switch y.(type) { case ratVal: return x, y case floatVal: - return rtof(x), y + return rtof(x1), y case complexVal: - return vtoc(x), y + return vtoc(x1), y } case floatVal: - switch y := y.(type) { + switch y.(type) { case floatVal: return x, y case complexVal: - return vtoc(x), y + return vtoc(x1), y } } |