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author | Daniil Cherednik <dan.cherednik@gmail.com> | 2022-11-24 13:14:34 +0300 |
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committer | Daniil Cherednik <dan.cherednik@gmail.com> | 2022-11-24 14:46:00 +0300 |
commit | 87f7fceed34bcafb8aaff351dd493a35c916986f (patch) | |
tree | 26809ec8f550aba8eb019e59adc3d48e51913eb2 /contrib/go/_std_1.18/src/runtime/float.go | |
parent | 11bc4015b8010ae201bf3eb33db7dba425aca35e (diff) | |
download | ydb-38c0b87ea9b8ab54a793f4246ecdee802a8227dc.tar.gz |
Ydb stable 22-4-4322.4.43
x-stable-origin-commit: 8d49d46cc834835bf3e50870516acd7376a63bcf
Diffstat (limited to 'contrib/go/_std_1.18/src/runtime/float.go')
-rw-r--r-- | contrib/go/_std_1.18/src/runtime/float.go | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/contrib/go/_std_1.18/src/runtime/float.go b/contrib/go/_std_1.18/src/runtime/float.go new file mode 100644 index 0000000000..459e58dd7e --- /dev/null +++ b/contrib/go/_std_1.18/src/runtime/float.go @@ -0,0 +1,53 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package runtime + +import "unsafe" + +var inf = float64frombits(0x7FF0000000000000) + +// isNaN reports whether f is an IEEE 754 ``not-a-number'' value. +func isNaN(f float64) (is bool) { + // IEEE 754 says that only NaNs satisfy f != f. + return f != f +} + +// isFinite reports whether f is neither NaN nor an infinity. +func isFinite(f float64) bool { + return !isNaN(f - f) +} + +// isInf reports whether f is an infinity. +func isInf(f float64) bool { + return !isNaN(f) && !isFinite(f) +} + +// Abs returns the absolute value of x. +// +// Special cases are: +// Abs(±Inf) = +Inf +// Abs(NaN) = NaN +func abs(x float64) float64 { + const sign = 1 << 63 + return float64frombits(float64bits(x) &^ sign) +} + +// copysign returns a value with the magnitude +// of x and the sign of y. +func copysign(x, y float64) float64 { + const sign = 1 << 63 + return float64frombits(float64bits(x)&^sign | float64bits(y)&sign) +} + +// Float64bits returns the IEEE 754 binary representation of f. +func float64bits(f float64) uint64 { + return *(*uint64)(unsafe.Pointer(&f)) +} + +// Float64frombits returns the floating point number corresponding +// the IEEE 754 binary representation b. +func float64frombits(b uint64) float64 { + return *(*float64)(unsafe.Pointer(&b)) +} |