| // Copyright 2016 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 test |
| |
| import ( |
| "math" |
| "testing" |
| ) |
| |
| //go:noinline |
| func compare1(a, b float64) bool { |
| return a < b |
| } |
| |
| //go:noinline |
| func compare2(a, b float32) bool { |
| return a < b |
| } |
| |
| func TestFloatCompare(t *testing.T) { |
| if !compare1(3, 5) { |
| t.Errorf("compare1 returned false") |
| } |
| if !compare2(3, 5) { |
| t.Errorf("compare2 returned false") |
| } |
| } |
| |
| func TestFloatCompareFolded(t *testing.T) { |
| // float64 comparisons |
| d1, d3, d5, d9 := float64(1), float64(3), float64(5), float64(9) |
| if d3 == d5 { |
| t.Errorf("d3 == d5 returned true") |
| } |
| if d3 != d3 { |
| t.Errorf("d3 != d3 returned true") |
| } |
| if d3 > d5 { |
| t.Errorf("d3 > d5 returned true") |
| } |
| if d3 >= d9 { |
| t.Errorf("d3 >= d9 returned true") |
| } |
| if d5 < d1 { |
| t.Errorf("d5 < d1 returned true") |
| } |
| if d9 <= d1 { |
| t.Errorf("d9 <= d1 returned true") |
| } |
| if math.NaN() == math.NaN() { |
| t.Errorf("math.NaN() == math.NaN() returned true") |
| } |
| if math.NaN() >= math.NaN() { |
| t.Errorf("math.NaN() >= math.NaN() returned true") |
| } |
| if math.NaN() <= math.NaN() { |
| t.Errorf("math.NaN() <= math.NaN() returned true") |
| } |
| if math.Copysign(math.NaN(), -1) < math.NaN() { |
| t.Errorf("math.Copysign(math.NaN(), -1) < math.NaN() returned true") |
| } |
| if math.Inf(1) != math.Inf(1) { |
| t.Errorf("math.Inf(1) != math.Inf(1) returned true") |
| } |
| if math.Inf(-1) != math.Inf(-1) { |
| t.Errorf("math.Inf(-1) != math.Inf(-1) returned true") |
| } |
| if math.Copysign(0, -1) != 0 { |
| t.Errorf("math.Copysign(0, -1) != 0 returned true") |
| } |
| if math.Copysign(0, -1) < 0 { |
| t.Errorf("math.Copysign(0, -1) < 0 returned true") |
| } |
| if 0 > math.Copysign(0, -1) { |
| t.Errorf("0 > math.Copysign(0, -1) returned true") |
| } |
| |
| // float32 comparisons |
| s1, s3, s5, s9 := float32(1), float32(3), float32(5), float32(9) |
| if s3 == s5 { |
| t.Errorf("s3 == s5 returned true") |
| } |
| if s3 != s3 { |
| t.Errorf("s3 != s3 returned true") |
| } |
| if s3 > s5 { |
| t.Errorf("s3 > s5 returned true") |
| } |
| if s3 >= s9 { |
| t.Errorf("s3 >= s9 returned true") |
| } |
| if s5 < s1 { |
| t.Errorf("s5 < s1 returned true") |
| } |
| if s9 <= s1 { |
| t.Errorf("s9 <= s1 returned true") |
| } |
| sPosNaN, sNegNaN := float32(math.NaN()), float32(math.Copysign(math.NaN(), -1)) |
| if sPosNaN == sPosNaN { |
| t.Errorf("sPosNaN == sPosNaN returned true") |
| } |
| if sPosNaN >= sPosNaN { |
| t.Errorf("sPosNaN >= sPosNaN returned true") |
| } |
| if sPosNaN <= sPosNaN { |
| t.Errorf("sPosNaN <= sPosNaN returned true") |
| } |
| if sNegNaN < sPosNaN { |
| t.Errorf("sNegNaN < sPosNaN returned true") |
| } |
| sPosInf, sNegInf := float32(math.Inf(1)), float32(math.Inf(-1)) |
| if sPosInf != sPosInf { |
| t.Errorf("sPosInf != sPosInf returned true") |
| } |
| if sNegInf != sNegInf { |
| t.Errorf("sNegInf != sNegInf returned true") |
| } |
| sNegZero := float32(math.Copysign(0, -1)) |
| if sNegZero != 0 { |
| t.Errorf("sNegZero != 0 returned true") |
| } |
| if sNegZero < 0 { |
| t.Errorf("sNegZero < 0 returned true") |
| } |
| if 0 > sNegZero { |
| t.Errorf("0 > sNegZero returned true") |
| } |
| } |
| |
| //go:noinline |
| func cvt1(a float64) uint64 { |
| return uint64(a) |
| } |
| |
| //go:noinline |
| func cvt2(a float64) uint32 { |
| return uint32(a) |
| } |
| |
| //go:noinline |
| func cvt3(a float32) uint64 { |
| return uint64(a) |
| } |
| |
| //go:noinline |
| func cvt4(a float32) uint32 { |
| return uint32(a) |
| } |
| |
| //go:noinline |
| func cvt5(a float64) int64 { |
| return int64(a) |
| } |
| |
| //go:noinline |
| func cvt6(a float64) int32 { |
| return int32(a) |
| } |
| |
| //go:noinline |
| func cvt7(a float32) int64 { |
| return int64(a) |
| } |
| |
| //go:noinline |
| func cvt8(a float32) int32 { |
| return int32(a) |
| } |
| |
| // make sure to cover int, uint cases (issue #16738) |
| // |
| //go:noinline |
| func cvt9(a float64) int { |
| return int(a) |
| } |
| |
| //go:noinline |
| func cvt10(a float64) uint { |
| return uint(a) |
| } |
| |
| //go:noinline |
| func cvt11(a float32) int { |
| return int(a) |
| } |
| |
| //go:noinline |
| func cvt12(a float32) uint { |
| return uint(a) |
| } |
| |
| //go:noinline |
| func f2i64p(v float64) *int64 { |
| return ip64(int64(v / 0.1)) |
| } |
| |
| //go:noinline |
| func ip64(v int64) *int64 { |
| return &v |
| } |
| |
| func TestFloatConvert(t *testing.T) { |
| if got := cvt1(3.5); got != 3 { |
| t.Errorf("cvt1 got %d, wanted 3", got) |
| } |
| if got := cvt2(3.5); got != 3 { |
| t.Errorf("cvt2 got %d, wanted 3", got) |
| } |
| if got := cvt3(3.5); got != 3 { |
| t.Errorf("cvt3 got %d, wanted 3", got) |
| } |
| if got := cvt4(3.5); got != 3 { |
| t.Errorf("cvt4 got %d, wanted 3", got) |
| } |
| if got := cvt5(3.5); got != 3 { |
| t.Errorf("cvt5 got %d, wanted 3", got) |
| } |
| if got := cvt6(3.5); got != 3 { |
| t.Errorf("cvt6 got %d, wanted 3", got) |
| } |
| if got := cvt7(3.5); got != 3 { |
| t.Errorf("cvt7 got %d, wanted 3", got) |
| } |
| if got := cvt8(3.5); got != 3 { |
| t.Errorf("cvt8 got %d, wanted 3", got) |
| } |
| if got := cvt9(3.5); got != 3 { |
| t.Errorf("cvt9 got %d, wanted 3", got) |
| } |
| if got := cvt10(3.5); got != 3 { |
| t.Errorf("cvt10 got %d, wanted 3", got) |
| } |
| if got := cvt11(3.5); got != 3 { |
| t.Errorf("cvt11 got %d, wanted 3", got) |
| } |
| if got := cvt12(3.5); got != 3 { |
| t.Errorf("cvt12 got %d, wanted 3", got) |
| } |
| if got := *f2i64p(10); got != 100 { |
| t.Errorf("f2i64p got %d, wanted 100", got) |
| } |
| } |
| |
| func TestFloatConvertFolded(t *testing.T) { |
| // Assign constants to variables so that they are (hopefully) constant folded |
| // by the SSA backend rather than the frontend. |
| u64, u32, u16, u8 := uint64(1<<63), uint32(1<<31), uint16(1<<15), uint8(1<<7) |
| i64, i32, i16, i8 := int64(-1<<63), int32(-1<<31), int16(-1<<15), int8(-1<<7) |
| du64, du32, du16, du8 := float64(1<<63), float64(1<<31), float64(1<<15), float64(1<<7) |
| di64, di32, di16, di8 := float64(-1<<63), float64(-1<<31), float64(-1<<15), float64(-1<<7) |
| su64, su32, su16, su8 := float32(1<<63), float32(1<<31), float32(1<<15), float32(1<<7) |
| si64, si32, si16, si8 := float32(-1<<63), float32(-1<<31), float32(-1<<15), float32(-1<<7) |
| |
| // integer to float |
| if float64(u64) != du64 { |
| t.Errorf("float64(u64) != du64") |
| } |
| if float64(u32) != du32 { |
| t.Errorf("float64(u32) != du32") |
| } |
| if float64(u16) != du16 { |
| t.Errorf("float64(u16) != du16") |
| } |
| if float64(u8) != du8 { |
| t.Errorf("float64(u8) != du8") |
| } |
| if float64(i64) != di64 { |
| t.Errorf("float64(i64) != di64") |
| } |
| if float64(i32) != di32 { |
| t.Errorf("float64(i32) != di32") |
| } |
| if float64(i16) != di16 { |
| t.Errorf("float64(i16) != di16") |
| } |
| if float64(i8) != di8 { |
| t.Errorf("float64(i8) != di8") |
| } |
| if float32(u64) != su64 { |
| t.Errorf("float32(u64) != su64") |
| } |
| if float32(u32) != su32 { |
| t.Errorf("float32(u32) != su32") |
| } |
| if float32(u16) != su16 { |
| t.Errorf("float32(u16) != su16") |
| } |
| if float32(u8) != su8 { |
| t.Errorf("float32(u8) != su8") |
| } |
| if float32(i64) != si64 { |
| t.Errorf("float32(i64) != si64") |
| } |
| if float32(i32) != si32 { |
| t.Errorf("float32(i32) != si32") |
| } |
| if float32(i16) != si16 { |
| t.Errorf("float32(i16) != si16") |
| } |
| if float32(i8) != si8 { |
| t.Errorf("float32(i8) != si8") |
| } |
| |
| // float to integer |
| if uint64(du64) != u64 { |
| t.Errorf("uint64(du64) != u64") |
| } |
| if uint32(du32) != u32 { |
| t.Errorf("uint32(du32) != u32") |
| } |
| if uint16(du16) != u16 { |
| t.Errorf("uint16(du16) != u16") |
| } |
| if uint8(du8) != u8 { |
| t.Errorf("uint8(du8) != u8") |
| } |
| if int64(di64) != i64 { |
| t.Errorf("int64(di64) != i64") |
| } |
| if int32(di32) != i32 { |
| t.Errorf("int32(di32) != i32") |
| } |
| if int16(di16) != i16 { |
| t.Errorf("int16(di16) != i16") |
| } |
| if int8(di8) != i8 { |
| t.Errorf("int8(di8) != i8") |
| } |
| if uint64(su64) != u64 { |
| t.Errorf("uint64(su64) != u64") |
| } |
| if uint32(su32) != u32 { |
| t.Errorf("uint32(su32) != u32") |
| } |
| if uint16(su16) != u16 { |
| t.Errorf("uint16(su16) != u16") |
| } |
| if uint8(su8) != u8 { |
| t.Errorf("uint8(su8) != u8") |
| } |
| if int64(si64) != i64 { |
| t.Errorf("int64(si64) != i64") |
| } |
| if int32(si32) != i32 { |
| t.Errorf("int32(si32) != i32") |
| } |
| if int16(si16) != i16 { |
| t.Errorf("int16(si16) != i16") |
| } |
| if int8(si8) != i8 { |
| t.Errorf("int8(si8) != i8") |
| } |
| } |
| |
| func TestFloat32StoreToLoadConstantFold(t *testing.T) { |
| // Test that math.Float32{,from}bits constant fold correctly. |
| // In particular we need to be careful that signaling NaN (sNaN) values |
| // are not converted to quiet NaN (qNaN) values during compilation. |
| // See issue #27193 for more information. |
| |
| // signaling NaNs |
| { |
| const nan = uint32(0x7f800001) // sNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| { |
| const nan = uint32(0x7fbfffff) // sNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| { |
| const nan = uint32(0xff800001) // sNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| { |
| const nan = uint32(0xffbfffff) // sNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| |
| // quiet NaNs |
| { |
| const nan = uint32(0x7fc00000) // qNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| { |
| const nan = uint32(0x7fffffff) // qNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| { |
| const nan = uint32(0x8fc00000) // qNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| { |
| const nan = uint32(0x8fffffff) // qNaN |
| if x := math.Float32bits(math.Float32frombits(nan)); x != nan { |
| t.Errorf("got %#x, want %#x", x, nan) |
| } |
| } |
| |
| // infinities |
| { |
| const inf = uint32(0x7f800000) // +∞ |
| if x := math.Float32bits(math.Float32frombits(inf)); x != inf { |
| t.Errorf("got %#x, want %#x", x, inf) |
| } |
| } |
| { |
| const negInf = uint32(0xff800000) // -∞ |
| if x := math.Float32bits(math.Float32frombits(negInf)); x != negInf { |
| t.Errorf("got %#x, want %#x", x, negInf) |
| } |
| } |
| |
| // numbers |
| { |
| const zero = uint32(0) // +0.0 |
| if x := math.Float32bits(math.Float32frombits(zero)); x != zero { |
| t.Errorf("got %#x, want %#x", x, zero) |
| } |
| } |
| { |
| const negZero = uint32(1 << 31) // -0.0 |
| if x := math.Float32bits(math.Float32frombits(negZero)); x != negZero { |
| t.Errorf("got %#x, want %#x", x, negZero) |
| } |
| } |
| { |
| const one = uint32(0x3f800000) // 1.0 |
| if x := math.Float32bits(math.Float32frombits(one)); x != one { |
| t.Errorf("got %#x, want %#x", x, one) |
| } |
| } |
| { |
| const negOne = uint32(0xbf800000) // -1.0 |
| if x := math.Float32bits(math.Float32frombits(negOne)); x != negOne { |
| t.Errorf("got %#x, want %#x", x, negOne) |
| } |
| } |
| { |
| const frac = uint32(0x3fc00000) // +1.5 |
| if x := math.Float32bits(math.Float32frombits(frac)); x != frac { |
| t.Errorf("got %#x, want %#x", x, frac) |
| } |
| } |
| { |
| const negFrac = uint32(0xbfc00000) // -1.5 |
| if x := math.Float32bits(math.Float32frombits(negFrac)); x != negFrac { |
| t.Errorf("got %#x, want %#x", x, negFrac) |
| } |
| } |
| } |
| |
| // Signaling NaN values as constants. |
| const ( |
| snan32bits uint32 = 0x7f800001 |
| snan64bits uint64 = 0x7ff0000000000001 |
| ) |
| |
| // Signaling NaNs as variables. |
| var snan32bitsVar uint32 = snan32bits |
| var snan64bitsVar uint64 = snan64bits |
| |
| func TestFloatSignalingNaN(t *testing.T) { |
| // Make sure we generate a signaling NaN from a constant properly. |
| // See issue 36400. |
| f32 := math.Float32frombits(snan32bits) |
| g32 := math.Float32frombits(snan32bitsVar) |
| x32 := math.Float32bits(f32) |
| y32 := math.Float32bits(g32) |
| if x32 != y32 { |
| t.Errorf("got %x, want %x (diff=%x)", x32, y32, x32^y32) |
| } |
| |
| f64 := math.Float64frombits(snan64bits) |
| g64 := math.Float64frombits(snan64bitsVar) |
| x64 := math.Float64bits(f64) |
| y64 := math.Float64bits(g64) |
| if x64 != y64 { |
| t.Errorf("got %x, want %x (diff=%x)", x64, y64, x64^y64) |
| } |
| } |
| |
| func TestFloatSignalingNaNConversion(t *testing.T) { |
| // Test to make sure when we convert a signaling NaN, we get a NaN. |
| // (Ideally we want a quiet NaN, but some platforms don't agree.) |
| // See issue 36399. |
| s32 := math.Float32frombits(snan32bitsVar) |
| if s32 == s32 { |
| t.Errorf("converting a NaN did not result in a NaN") |
| } |
| s64 := math.Float64frombits(snan64bitsVar) |
| if s64 == s64 { |
| t.Errorf("converting a NaN did not result in a NaN") |
| } |
| } |
| |
| func TestFloatSignalingNaNConversionConst(t *testing.T) { |
| // Test to make sure when we convert a signaling NaN, it converts to a NaN. |
| // (Ideally we want a quiet NaN, but some platforms don't agree.) |
| // See issue 36399 and 36400. |
| s32 := math.Float32frombits(snan32bits) |
| if s32 == s32 { |
| t.Errorf("converting a NaN did not result in a NaN") |
| } |
| s64 := math.Float64frombits(snan64bits) |
| if s64 == s64 { |
| t.Errorf("converting a NaN did not result in a NaN") |
| } |
| } |
| |
| //go:noinline |
| func isPosInf(x float64) bool { |
| return math.IsInf(x, 1) |
| } |
| |
| //go:noinline |
| func isPosInfEq(x float64) bool { |
| return x == math.Inf(1) |
| } |
| |
| //go:noinline |
| func isPosInfCmp(x float64) bool { |
| return x > math.MaxFloat64 |
| } |
| |
| //go:noinline |
| func isNotPosInf(x float64) bool { |
| return !math.IsInf(x, 1) |
| } |
| |
| //go:noinline |
| func isNotPosInfEq(x float64) bool { |
| return x != math.Inf(1) |
| } |
| |
| //go:noinline |
| func isNotPosInfCmp(x float64) bool { |
| return x <= math.MaxFloat64 |
| } |
| |
| //go:noinline |
| func isNegInf(x float64) bool { |
| return math.IsInf(x, -1) |
| } |
| |
| //go:noinline |
| func isNegInfEq(x float64) bool { |
| return x == math.Inf(-1) |
| } |
| |
| //go:noinline |
| func isNegInfCmp(x float64) bool { |
| return x < -math.MaxFloat64 |
| } |
| |
| //go:noinline |
| func isNotNegInf(x float64) bool { |
| return !math.IsInf(x, -1) |
| } |
| |
| //go:noinline |
| func isNotNegInfEq(x float64) bool { |
| return x != math.Inf(-1) |
| } |
| |
| //go:noinline |
| func isNotNegInfCmp(x float64) bool { |
| return x >= -math.MaxFloat64 |
| } |
| |
| func TestInf(t *testing.T) { |
| tests := []struct { |
| value float64 |
| isPosInf bool |
| isNegInf bool |
| isNaN bool |
| }{ |
| {value: math.Inf(1), isPosInf: true}, |
| {value: math.MaxFloat64}, |
| {value: math.Inf(-1), isNegInf: true}, |
| {value: -math.MaxFloat64}, |
| {value: math.NaN(), isNaN: true}, |
| } |
| |
| check := func(name string, f func(x float64) bool, value float64, want bool) { |
| got := f(value) |
| if got != want { |
| t.Errorf("%v(%g): want %v, got %v", name, value, want, got) |
| } |
| } |
| |
| for _, test := range tests { |
| check("isPosInf", isPosInf, test.value, test.isPosInf) |
| check("isPosInfEq", isPosInfEq, test.value, test.isPosInf) |
| check("isPosInfCmp", isPosInfCmp, test.value, test.isPosInf) |
| |
| check("isNotPosInf", isNotPosInf, test.value, !test.isPosInf) |
| check("isNotPosInfEq", isNotPosInfEq, test.value, !test.isPosInf) |
| check("isNotPosInfCmp", isNotPosInfCmp, test.value, !test.isPosInf && !test.isNaN) |
| |
| check("isNegInf", isNegInf, test.value, test.isNegInf) |
| check("isNegInfEq", isNegInfEq, test.value, test.isNegInf) |
| check("isNegInfCmp", isNegInfCmp, test.value, test.isNegInf) |
| |
| check("isNotNegInf", isNotNegInf, test.value, !test.isNegInf) |
| check("isNotNegInfEq", isNotNegInfEq, test.value, !test.isNegInf) |
| check("isNotNegInfCmp", isNotNegInfCmp, test.value, !test.isNegInf && !test.isNaN) |
| } |
| } |
| |
| //go:noinline |
| func isNaNOrGtZero64(x float64) bool { |
| return math.IsNaN(x) || x > 0 |
| } |
| |
| //go:noinline |
| func isNaNOrGteZero64(x float64) bool { |
| return x >= 0 || math.IsNaN(x) |
| } |
| |
| //go:noinline |
| func isNaNOrLtZero64(x float64) bool { |
| return x < 0 || math.IsNaN(x) |
| } |
| |
| //go:noinline |
| func isNaNOrLteZero64(x float64) bool { |
| return math.IsNaN(x) || x <= 0 |
| } |
| |
| func TestFusedNaNChecks64(t *testing.T) { |
| tests := []struct { |
| value float64 |
| isZero bool |
| isGreaterThanZero bool |
| isLessThanZero bool |
| isNaN bool |
| }{ |
| {value: 0.0, isZero: true}, |
| {value: math.Copysign(0, -1), isZero: true}, |
| {value: 1.0, isGreaterThanZero: true}, |
| {value: -1.0, isLessThanZero: true}, |
| {value: math.Inf(1), isGreaterThanZero: true}, |
| {value: math.Inf(-1), isLessThanZero: true}, |
| {value: math.NaN(), isNaN: true}, |
| } |
| |
| check := func(name string, f func(x float64) bool, value float64, want bool) { |
| got := f(value) |
| if got != want { |
| t.Errorf("%v(%g): want %v, got %v", name, value, want, got) |
| } |
| } |
| |
| for _, test := range tests { |
| check("isNaNOrGtZero64", isNaNOrGtZero64, test.value, test.isNaN || test.isGreaterThanZero) |
| check("isNaNOrGteZero64", isNaNOrGteZero64, test.value, test.isNaN || test.isGreaterThanZero || test.isZero) |
| check("isNaNOrLtZero64", isNaNOrLtZero64, test.value, test.isNaN || test.isLessThanZero) |
| check("isNaNOrLteZero64", isNaNOrLteZero64, test.value, test.isNaN || test.isLessThanZero || test.isZero) |
| } |
| } |
| |
| //go:noinline |
| func isNaNOrGtZero32(x float32) bool { |
| return x > 0 || x != x |
| } |
| |
| //go:noinline |
| func isNaNOrGteZero32(x float32) bool { |
| return x != x || x >= 0 |
| } |
| |
| //go:noinline |
| func isNaNOrLtZero32(x float32) bool { |
| return x != x || x < 0 |
| } |
| |
| //go:noinline |
| func isNaNOrLteZero32(x float32) bool { |
| return x <= 0 || x != x |
| } |
| |
| func TestFusedNaNChecks32(t *testing.T) { |
| tests := []struct { |
| value float32 |
| isZero bool |
| isGreaterThanZero bool |
| isLessThanZero bool |
| isNaN bool |
| }{ |
| {value: 0.0, isZero: true}, |
| {value: float32(math.Copysign(0, -1)), isZero: true}, |
| {value: 1.0, isGreaterThanZero: true}, |
| {value: -1.0, isLessThanZero: true}, |
| {value: float32(math.Inf(1)), isGreaterThanZero: true}, |
| {value: float32(math.Inf(-1)), isLessThanZero: true}, |
| {value: float32(math.NaN()), isNaN: true}, |
| } |
| |
| check := func(name string, f func(x float32) bool, value float32, want bool) { |
| got := f(value) |
| if got != want { |
| t.Errorf("%v(%g): want %v, got %v", name, value, want, got) |
| } |
| } |
| |
| for _, test := range tests { |
| check("isNaNOrGtZero32", isNaNOrGtZero32, test.value, test.isNaN || test.isGreaterThanZero) |
| check("isNaNOrGteZero32", isNaNOrGteZero32, test.value, test.isNaN || test.isGreaterThanZero || test.isZero) |
| check("isNaNOrLtZero32", isNaNOrLtZero32, test.value, test.isNaN || test.isLessThanZero) |
| check("isNaNOrLteZero32", isNaNOrLteZero32, test.value, test.isNaN || test.isLessThanZero || test.isZero) |
| } |
| } |
| |
| // minNormal64 is the smallest float64 value that is not subnormal. |
| const minNormal64 = 2.2250738585072014e-308 |
| |
| //go:noinline |
| func isAbsLessThanMinNormal64(x float64) bool { |
| return math.Abs(x) < minNormal64 |
| } |
| |
| //go:noinline |
| func isLessThanMinNormal64(x float64) bool { |
| return x < minNormal64 |
| } |
| |
| //go:noinline |
| func isGreaterThanNegMinNormal64(x float64) bool { |
| return x > -minNormal64 |
| } |
| |
| //go:noinline |
| func isGreaterThanOrEqualToMinNormal64(x float64) bool { |
| return math.Abs(x) >= minNormal64 |
| } |
| |
| func TestSubnormalComparisons(t *testing.T) { |
| tests := []struct { |
| value float64 |
| isAbsLessThanMinNormal bool |
| isPositive bool |
| isNegative bool |
| isNaN bool |
| }{ |
| {value: math.Inf(1), isPositive: true}, |
| {value: math.MaxFloat64, isPositive: true}, |
| {value: math.Inf(-1), isNegative: true}, |
| {value: -math.MaxFloat64, isNegative: true}, |
| {value: math.NaN(), isNaN: true}, |
| {value: minNormal64, isPositive: true}, |
| {value: minNormal64 / 2, isAbsLessThanMinNormal: true, isPositive: true}, |
| {value: -minNormal64, isNegative: true}, |
| {value: -minNormal64 / 2, isAbsLessThanMinNormal: true, isNegative: true}, |
| {value: 0, isAbsLessThanMinNormal: true, isPositive: true}, |
| {value: math.Copysign(0, -1), isAbsLessThanMinNormal: true, isNegative: true}, |
| } |
| |
| check := func(name string, f func(x float64) bool, value float64, want bool) { |
| got := f(value) |
| if got != want { |
| t.Errorf("%v(%g): want %v, got %v", name, value, want, got) |
| } |
| } |
| |
| for _, test := range tests { |
| check("isAbsLessThanMinNormal64", isAbsLessThanMinNormal64, test.value, test.isAbsLessThanMinNormal) |
| check("isLessThanMinNormal64", isLessThanMinNormal64, test.value, test.isAbsLessThanMinNormal || test.isNegative) |
| check("isGreaterThanNegMinNormal64", isGreaterThanNegMinNormal64, test.value, test.isAbsLessThanMinNormal || test.isPositive) |
| check("isGreaterThanOrEqualToMinNormal64", isGreaterThanOrEqualToMinNormal64, test.value, !test.isAbsLessThanMinNormal && !test.isNaN) |
| } |
| } |
| |
| var sinkFloat float64 |
| |
| func BenchmarkMul2(b *testing.B) { |
| for i := 0; i < b.N; i++ { |
| var m float64 = 1 |
| for j := 0; j < 500; j++ { |
| m *= 2 |
| } |
| sinkFloat = m |
| } |
| } |
| func BenchmarkMulNeg2(b *testing.B) { |
| for i := 0; i < b.N; i++ { |
| var m float64 = 1 |
| for j := 0; j < 500; j++ { |
| m *= -2 |
| } |
| sinkFloat = m |
| } |
| } |
