-5.0106036182710749e+00,
}
-type compareTest[F float32 | float64] struct {
- x, y F
- want int
-}
-
-func compareCasesFloat64() []compareTest[float64] {
- zero, nan, inf := 0.0, NaN(), Inf(0)
-
- // construct -NaN manually from its bit representation,
- // since IEEE doesn't mandate negate(NaN) change the sign bit
- unegnan := Float64bits(nan)
- unegnan ^= 1 << 63
- negnan := Float64frombits(unegnan)
- return []compareTest[float64]{
- {negnan, -inf, -1},
- {-inf, negnan, 1},
- {-inf, -Pi, -1},
- {-Pi, -inf, 1},
- {-Pi, -zero, -1},
- {-zero, -Pi, 1},
- {-zero, 0, -1},
- {0, -zero, 1},
- {0, Pi, -1},
- {Pi, 0, 1},
- {Pi, inf, -1},
- {inf, Pi, 1},
- {inf, nan, -1},
- {nan, inf, 1},
- {Pi, Pi, 0},
- {negnan, negnan, 0},
- }
-}
-
-func compareCasesFloat32() []compareTest[float32] {
- zero, nan, inf := float32(0.0), float32(NaN()), float32(Inf(0))
-
- // construct -NaN manually from its bit representation,
- // since IEEE doesn't mandate negate(NaN) change the sign bit
- unegnan := Float32bits(nan)
- unegnan ^= 1 << 31
- negnan := Float32frombits(unegnan)
- return []compareTest[float32]{
- {negnan, -inf, -1},
- {-inf, negnan, 1},
- {-inf, -Pi, -1},
- {-Pi, -inf, 1},
- {-Pi, -zero, -1},
- {-zero, -Pi, 1},
- {-zero, 0, -1},
- {0, -zero, 1},
- {0, Pi, -1},
- {Pi, 0, 1},
- {Pi, inf, -1},
- {inf, Pi, 1},
- {inf, nan, -1},
- {nan, inf, 1},
- {Pi, Pi, 0},
- {negnan, negnan, 0},
- }
-}
-
func tolerance(a, b, e float64) bool {
// Multiplying by e here can underflow denormal values to zero.
// Check a==b so that at least if a and b are small and identical
}
}
-func TestCompare(t *testing.T) {
- // -NaN < -∞ < -3.14 < -0 < 0 < 3.14 < ∞ < NaN
- for _, c := range compareCasesFloat64() {
- cmp := Compare(c.x, c.y)
- if cmp != c.want {
- t.Errorf("Compare(%v, %v) = %d, want %v", c.x, c.y, cmp, c.want)
- }
- }
- for _, c := range compareCasesFloat32() {
- cmp := Compare32(c.x, c.y)
- if cmp != c.want {
- t.Errorf("Compare32(%v, %v) = %d, want %v", c.x, c.y, cmp, c.want)
- }
- }
-}
-
func TestCopysign(t *testing.T) {
for i := 0; i < len(vf); i++ {
if f := Copysign(vf[i], -1); copysign[i] != f {
GlobalF = x
}
-func BenchmarkCompare(b *testing.B) {
- x := 0
- for i := 0; i < b.N; i++ {
- x = Compare(GlobalF, 1.5)
- }
- GlobalI = x
-}
-
-func BenchmarkCompare32(b *testing.B) {
- x := 0
- globalF32 := float32(GlobalF)
- for i := 0; i < b.N; i++ {
- x = Compare32(globalF32, 1.5)
- }
- GlobalI = x
-}
-
var copysignNeg = -1.0
func BenchmarkCopysign(b *testing.B) {
+++ /dev/null
-// Copyright 2023 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
-
-func sign[I int32 | int64](a, b I) int {
- if a < b {
- return -1
- }
- if a > b {
- return 1
- }
- return 0
-}
-
-// Compare compares a and b such that
-// -NaN is ordered before any other value,
-// +NaN is ordered after any other value,
-// and -0 is ordered before +0.
-// In other words, it defines a total order over floats
-// (according to the total-ordering predicate in IEEE-754, section 5.10).
-// It returns 0 if a == b, -1 if a < b, and +1 if a > b.
-func Compare(a, b float64) int {
- // Perform a bitwise comparison (a < b) by casting the float64s into an int64s.
- x := int64(Float64bits(a))
- y := int64(Float64bits(b))
-
- // If a and b are both negative, flip the comparison so that we check a > b.
- if x < 0 && y < 0 {
- return sign(y, x)
- }
- return sign(x, y)
-}
-
-// Compare32 compares a and b such that
-// -NaN is ordered before any other value,
-// +NaN is ordered after any other value,
-// and -0 is ordered before +0.
-// In other words, it defines a total order over floats
-// (according to the total-ordering predicate in IEEE-754, section 5.10).
-// It returns 0 if a == b, -1 if a < b, and +1 if a > b.
-func Compare32(a, b float32) int {
- // Perform a bitwise comparison (a < b) by casting the float32s into an int32s.
- x := int32(Float32bits(a))
- y := int32(Float32bits(b))
-
- // If a and b are both negative, flip the comparison so that we check a > b.
- if x < 0 && y < 0 {
- return sign(y, x)
- }
- return sign(x, y)
-}