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Diffstat (limited to '')
-rw-r--r-- | src/runtime/internal/math/math.go | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/src/runtime/internal/math/math.go b/src/runtime/internal/math/math.go new file mode 100644 index 0000000..5385f5d --- /dev/null +++ b/src/runtime/internal/math/math.go @@ -0,0 +1,19 @@ +// Copyright 2018 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 math + +import "runtime/internal/sys" + +const MaxUintptr = ^uintptr(0) + +// MulUintptr returns a * b and whether the multiplication overflowed. +// On supported platforms this is an intrinsic lowered by the compiler. +func MulUintptr(a, b uintptr) (uintptr, bool) { + if a|b < 1<<(4*sys.PtrSize) || a == 0 { + return a * b, false + } + overflow := b > MaxUintptr/a + return a * b, overflow +} |