unsafe.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package math
     6  
     7  import "unsafe"
     8  
     9  // Despite being an exported symbol,
    10  // Float32bits is linknamed by widely used packages.
    11  // Notable members of the hall of shame include:
    12  //   - gitee.com/quant1x/num
    13  //
    14  // Do not remove or change the type signature.
    15  // See go.dev/issue/67401.
    16  //
    17  // Note that this comment is not part of the doc comment.
    18  //
    19  //go:linkname Float32bits
    20  
    21  // Float32bits returns the IEEE 754 binary representation of f,
    22  // with the sign bit of f and the result in the same bit position.
    23  // Float32bits(Float32frombits(x)) == x.
    24  func Float32bits(f float32) uint32 { return *(*uint32)(unsafe.Pointer(&f)) }
    25  
    26  // Float32frombits returns the floating-point number corresponding
    27  // to the IEEE 754 binary representation b, with the sign bit of b
    28  // and the result in the same bit position.
    29  // Float32frombits(Float32bits(x)) == x.
    30  func Float32frombits(b uint32) float32 { return *(*float32)(unsafe.Pointer(&b)) }
    31  
    32  // Float64bits returns the IEEE 754 binary representation of f,
    33  // with the sign bit of f and the result in the same bit position,
    34  // and Float64bits(Float64frombits(x)) == x.
    35  func Float64bits(f float64) uint64 { return *(*uint64)(unsafe.Pointer(&f)) }
    36  
    37  // Float64frombits returns the floating-point number corresponding
    38  // to the IEEE 754 binary representation b, with the sign bit of b
    39  // and the result in the same bit position.
    40  // Float64frombits(Float64bits(x)) == x.
    41  func Float64frombits(b uint64) float64 { return *(*float64)(unsafe.Pointer(&b)) }
    42
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