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-rw-r--r--src/math/big/floatconv_test.go825
1 files changed, 825 insertions, 0 deletions
diff --git a/src/math/big/floatconv_test.go b/src/math/big/floatconv_test.go
new file mode 100644
index 0000000..a1cc38a
--- /dev/null
+++ b/src/math/big/floatconv_test.go
@@ -0,0 +1,825 @@
+// Copyright 2015 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 big
+
+import (
+ "bytes"
+ "fmt"
+ "math"
+ "math/bits"
+ "strconv"
+ "testing"
+)
+
+var zero_ float64
+
+func TestFloatSetFloat64String(t *testing.T) {
+ inf := math.Inf(0)
+ nan := math.NaN()
+
+ for _, test := range []struct {
+ s string
+ x float64 // NaNs represent invalid inputs
+ }{
+ // basics
+ {"0", 0},
+ {"-0", -zero_},
+ {"+0", 0},
+ {"1", 1},
+ {"-1", -1},
+ {"+1", 1},
+ {"1.234", 1.234},
+ {"-1.234", -1.234},
+ {"+1.234", 1.234},
+ {".1", 0.1},
+ {"1.", 1},
+ {"+1.", 1},
+
+ // various zeros
+ {"0e100", 0},
+ {"-0e+100", -zero_},
+ {"+0e-100", 0},
+ {"0E100", 0},
+ {"-0E+100", -zero_},
+ {"+0E-100", 0},
+
+ // various decimal exponent formats
+ {"1.e10", 1e10},
+ {"1e+10", 1e10},
+ {"+1e-10", 1e-10},
+ {"1E10", 1e10},
+ {"1.E+10", 1e10},
+ {"+1E-10", 1e-10},
+
+ // infinities
+ {"Inf", inf},
+ {"+Inf", inf},
+ {"-Inf", -inf},
+ {"inf", inf},
+ {"+inf", inf},
+ {"-inf", -inf},
+
+ // invalid numbers
+ {"", nan},
+ {"-", nan},
+ {"0x", nan},
+ {"0e", nan},
+ {"1.2ef", nan},
+ {"2..3", nan},
+ {"123..", nan},
+ {"infinity", nan},
+ {"foobar", nan},
+
+ // invalid underscores
+ {"_", nan},
+ {"0_", nan},
+ {"1__0", nan},
+ {"123_.", nan},
+ {"123._", nan},
+ {"123._4", nan},
+ {"1_2.3_4_", nan},
+ {"_.123", nan},
+ {"_123.456", nan},
+ {"10._0", nan},
+ {"10.0e_0", nan},
+ {"10.0e0_", nan},
+ {"0P-0__0", nan},
+
+ // misc decimal values
+ {"3.14159265", 3.14159265},
+ {"-687436.79457e-245", -687436.79457e-245},
+ {"-687436.79457E245", -687436.79457e245},
+ {".0000000000000000000000000000000000000001", 1e-40},
+ {"+10000000000000000000000000000000000000000e-0", 1e40},
+
+ // decimal mantissa, binary exponent
+ {"0p0", 0},
+ {"-0p0", -zero_},
+ {"1p10", 1 << 10},
+ {"1p+10", 1 << 10},
+ {"+1p-10", 1.0 / (1 << 10)},
+ {"1024p-12", 0.25},
+ {"-1p10", -1024},
+ {"1.5p1", 3},
+
+ // binary mantissa, decimal exponent
+ {"0b0", 0},
+ {"-0b0", -zero_},
+ {"0b0e+10", 0},
+ {"-0b0e-10", -zero_},
+ {"0b1010", 10},
+ {"0B1010E2", 1000},
+ {"0b.1", 0.5},
+ {"0b.001", 0.125},
+ {"0b.001e3", 125},
+
+ // binary mantissa, binary exponent
+ {"0b0p+10", 0},
+ {"-0b0p-10", -zero_},
+ {"0b.1010p4", 10},
+ {"0b1p-1", 0.5},
+ {"0b001p-3", 0.125},
+ {"0b.001p3", 1},
+ {"0b0.01p2", 1},
+ {"0b0.01P+2", 1},
+
+ // octal mantissa, decimal exponent
+ {"0o0", 0},
+ {"-0o0", -zero_},
+ {"0o0e+10", 0},
+ {"-0o0e-10", -zero_},
+ {"0o12", 10},
+ {"0O12E2", 1000},
+ {"0o.4", 0.5},
+ {"0o.01", 0.015625},
+ {"0o.01e3", 15.625},
+
+ // octal mantissa, binary exponent
+ {"0o0p+10", 0},
+ {"-0o0p-10", -zero_},
+ {"0o.12p6", 10},
+ {"0o4p-3", 0.5},
+ {"0o0014p-6", 0.1875},
+ {"0o.001p9", 1},
+ {"0o0.01p7", 2},
+ {"0O0.01P+2", 0.0625},
+
+ // hexadecimal mantissa and exponent
+ {"0x0", 0},
+ {"-0x0", -zero_},
+ {"0x0p+10", 0},
+ {"-0x0p-10", -zero_},
+ {"0xff", 255},
+ {"0X.8p1", 1},
+ {"-0X0.00008p16", -0.5},
+ {"-0X0.00008P+16", -0.5},
+ {"0x0.0000000000001p-1022", math.SmallestNonzeroFloat64},
+ {"0x1.fffffffffffffp1023", math.MaxFloat64},
+
+ // underscores
+ {"0_0", 0},
+ {"1_000.", 1000},
+ {"1_2_3.4_5_6", 123.456},
+ {"1.0e0_0", 1},
+ {"1p+1_0", 1024},
+ {"0b_1000", 0x8},
+ {"0b_1011_1101", 0xbd},
+ {"0x_f0_0d_1eP+0_8", 0xf00d1e00},
+ } {
+ var x Float
+ x.SetPrec(53)
+ _, ok := x.SetString(test.s)
+ if math.IsNaN(test.x) {
+ // test.s is invalid
+ if ok {
+ t.Errorf("%s: want parse error", test.s)
+ }
+ continue
+ }
+ // test.s is valid
+ if !ok {
+ t.Errorf("%s: got parse error", test.s)
+ continue
+ }
+ f, _ := x.Float64()
+ want := new(Float).SetFloat64(test.x)
+ if x.Cmp(want) != 0 || x.Signbit() != want.Signbit() {
+ t.Errorf("%s: got %v (%v); want %v", test.s, &x, f, test.x)
+ }
+ }
+}
+
+func fdiv(a, b float64) float64 { return a / b }
+
+const (
+ below1e23 = 99999999999999974834176
+ above1e23 = 100000000000000008388608
+)
+
+func TestFloat64Text(t *testing.T) {
+ for _, test := range []struct {
+ x float64
+ format byte
+ prec int
+ want string
+ }{
+ {0, 'f', 0, "0"},
+ {math.Copysign(0, -1), 'f', 0, "-0"},
+ {1, 'f', 0, "1"},
+ {-1, 'f', 0, "-1"},
+
+ {0.001, 'e', 0, "1e-03"},
+ {0.459, 'e', 0, "5e-01"},
+ {1.459, 'e', 0, "1e+00"},
+ {2.459, 'e', 1, "2.5e+00"},
+ {3.459, 'e', 2, "3.46e+00"},
+ {4.459, 'e', 3, "4.459e+00"},
+ {5.459, 'e', 4, "5.4590e+00"},
+
+ {0.001, 'f', 0, "0"},
+ {0.459, 'f', 0, "0"},
+ {1.459, 'f', 0, "1"},
+ {2.459, 'f', 1, "2.5"},
+ {3.459, 'f', 2, "3.46"},
+ {4.459, 'f', 3, "4.459"},
+ {5.459, 'f', 4, "5.4590"},
+
+ {0, 'b', 0, "0"},
+ {math.Copysign(0, -1), 'b', 0, "-0"},
+ {1.0, 'b', 0, "4503599627370496p-52"},
+ {-1.0, 'b', 0, "-4503599627370496p-52"},
+ {4503599627370496, 'b', 0, "4503599627370496p+0"},
+
+ {0, 'p', 0, "0"},
+ {math.Copysign(0, -1), 'p', 0, "-0"},
+ {1024.0, 'p', 0, "0x.8p+11"},
+ {-1024.0, 'p', 0, "-0x.8p+11"},
+
+ // all test cases below from strconv/ftoa_test.go
+ {1, 'e', 5, "1.00000e+00"},
+ {1, 'f', 5, "1.00000"},
+ {1, 'g', 5, "1"},
+ {1, 'g', -1, "1"},
+ {20, 'g', -1, "20"},
+ {1234567.8, 'g', -1, "1.2345678e+06"},
+ {200000, 'g', -1, "200000"},
+ {2000000, 'g', -1, "2e+06"},
+
+ // g conversion and zero suppression
+ {400, 'g', 2, "4e+02"},
+ {40, 'g', 2, "40"},
+ {4, 'g', 2, "4"},
+ {.4, 'g', 2, "0.4"},
+ {.04, 'g', 2, "0.04"},
+ {.004, 'g', 2, "0.004"},
+ {.0004, 'g', 2, "0.0004"},
+ {.00004, 'g', 2, "4e-05"},
+ {.000004, 'g', 2, "4e-06"},
+
+ {0, 'e', 5, "0.00000e+00"},
+ {0, 'f', 5, "0.00000"},
+ {0, 'g', 5, "0"},
+ {0, 'g', -1, "0"},
+
+ {-1, 'e', 5, "-1.00000e+00"},
+ {-1, 'f', 5, "-1.00000"},
+ {-1, 'g', 5, "-1"},
+ {-1, 'g', -1, "-1"},
+
+ {12, 'e', 5, "1.20000e+01"},
+ {12, 'f', 5, "12.00000"},
+ {12, 'g', 5, "12"},
+ {12, 'g', -1, "12"},
+
+ {123456700, 'e', 5, "1.23457e+08"},
+ {123456700, 'f', 5, "123456700.00000"},
+ {123456700, 'g', 5, "1.2346e+08"},
+ {123456700, 'g', -1, "1.234567e+08"},
+
+ {1.2345e6, 'e', 5, "1.23450e+06"},
+ {1.2345e6, 'f', 5, "1234500.00000"},
+ {1.2345e6, 'g', 5, "1.2345e+06"},
+
+ {1e23, 'e', 17, "9.99999999999999916e+22"},
+ {1e23, 'f', 17, "99999999999999991611392.00000000000000000"},
+ {1e23, 'g', 17, "9.9999999999999992e+22"},
+
+ {1e23, 'e', -1, "1e+23"},
+ {1e23, 'f', -1, "100000000000000000000000"},
+ {1e23, 'g', -1, "1e+23"},
+
+ {below1e23, 'e', 17, "9.99999999999999748e+22"},
+ {below1e23, 'f', 17, "99999999999999974834176.00000000000000000"},
+ {below1e23, 'g', 17, "9.9999999999999975e+22"},
+
+ {below1e23, 'e', -1, "9.999999999999997e+22"},
+ {below1e23, 'f', -1, "99999999999999970000000"},
+ {below1e23, 'g', -1, "9.999999999999997e+22"},
+
+ {above1e23, 'e', 17, "1.00000000000000008e+23"},
+ {above1e23, 'f', 17, "100000000000000008388608.00000000000000000"},
+ {above1e23, 'g', 17, "1.0000000000000001e+23"},
+
+ {above1e23, 'e', -1, "1.0000000000000001e+23"},
+ {above1e23, 'f', -1, "100000000000000010000000"},
+ {above1e23, 'g', -1, "1.0000000000000001e+23"},
+
+ {5e-304 / 1e20, 'g', -1, "5e-324"},
+ {-5e-304 / 1e20, 'g', -1, "-5e-324"},
+ {fdiv(5e-304, 1e20), 'g', -1, "5e-324"}, // avoid constant arithmetic
+ {fdiv(-5e-304, 1e20), 'g', -1, "-5e-324"}, // avoid constant arithmetic
+
+ {32, 'g', -1, "32"},
+ {32, 'g', 0, "3e+01"},
+
+ {100, 'x', -1, "0x1.9p+06"},
+
+ // {math.NaN(), 'g', -1, "NaN"}, // Float doesn't support NaNs
+ // {-math.NaN(), 'g', -1, "NaN"}, // Float doesn't support NaNs
+ {math.Inf(0), 'g', -1, "+Inf"},
+ {math.Inf(-1), 'g', -1, "-Inf"},
+ {-math.Inf(0), 'g', -1, "-Inf"},
+
+ {-1, 'b', -1, "-4503599627370496p-52"},
+
+ // fixed bugs
+ {0.9, 'f', 1, "0.9"},
+ {0.09, 'f', 1, "0.1"},
+ {0.0999, 'f', 1, "0.1"},
+ {0.05, 'f', 1, "0.1"},
+ {0.05, 'f', 0, "0"},
+ {0.5, 'f', 1, "0.5"},
+ {0.5, 'f', 0, "0"},
+ {1.5, 'f', 0, "2"},
+
+ // https://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/
+ {2.2250738585072012e-308, 'g', -1, "2.2250738585072014e-308"},
+ // https://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/
+ {2.2250738585072011e-308, 'g', -1, "2.225073858507201e-308"},
+
+ // Issue 2625.
+ {383260575764816448, 'f', 0, "383260575764816448"},
+ {383260575764816448, 'g', -1, "3.8326057576481645e+17"},
+
+ // Issue 15918.
+ {1, 'f', -10, "1"},
+ {1, 'f', -11, "1"},
+ {1, 'f', -12, "1"},
+ } {
+ // The test cases are from the strconv package which tests float64 values.
+ // When formatting values with prec = -1 (shortest representation),
+ // the actually available mantissa precision matters.
+ // For denormalized values, that precision is < 53 (SetFloat64 default).
+ // Compute and set the actual precision explicitly.
+ f := new(Float).SetPrec(actualPrec(test.x)).SetFloat64(test.x)
+ got := f.Text(test.format, test.prec)
+ if got != test.want {
+ t.Errorf("%v: got %s; want %s", test, got, test.want)
+ continue
+ }
+
+ if test.format == 'b' && test.x == 0 {
+ continue // 'b' format in strconv.Float requires knowledge of bias for 0.0
+ }
+ if test.format == 'p' {
+ continue // 'p' format not supported in strconv.Format
+ }
+
+ // verify that Float format matches strconv format
+ want := strconv.FormatFloat(test.x, test.format, test.prec, 64)
+ if got != want {
+ t.Errorf("%v: got %s; want %s (strconv)", test, got, want)
+ }
+ }
+}
+
+// actualPrec returns the number of actually used mantissa bits.
+func actualPrec(x float64) uint {
+ if mant := math.Float64bits(x); x != 0 && mant&(0x7ff<<52) == 0 {
+ // x is denormalized
+ return 64 - uint(bits.LeadingZeros64(mant&(1<<52-1)))
+ }
+ return 53
+}
+
+func TestFloatText(t *testing.T) {
+ const defaultRound = ^RoundingMode(0)
+
+ for _, test := range []struct {
+ x string
+ round RoundingMode
+ prec uint
+ format byte
+ digits int
+ want string
+ }{
+ {"0", defaultRound, 10, 'f', 0, "0"},
+ {"-0", defaultRound, 10, 'f', 0, "-0"},
+ {"1", defaultRound, 10, 'f', 0, "1"},
+ {"-1", defaultRound, 10, 'f', 0, "-1"},
+
+ {"1.459", defaultRound, 100, 'e', 0, "1e+00"},
+ {"2.459", defaultRound, 100, 'e', 1, "2.5e+00"},
+ {"3.459", defaultRound, 100, 'e', 2, "3.46e+00"},
+ {"4.459", defaultRound, 100, 'e', 3, "4.459e+00"},
+ {"5.459", defaultRound, 100, 'e', 4, "5.4590e+00"},
+
+ {"1.459", defaultRound, 100, 'E', 0, "1E+00"},
+ {"2.459", defaultRound, 100, 'E', 1, "2.5E+00"},
+ {"3.459", defaultRound, 100, 'E', 2, "3.46E+00"},
+ {"4.459", defaultRound, 100, 'E', 3, "4.459E+00"},
+ {"5.459", defaultRound, 100, 'E', 4, "5.4590E+00"},
+
+ {"1.459", defaultRound, 100, 'f', 0, "1"},
+ {"2.459", defaultRound, 100, 'f', 1, "2.5"},
+ {"3.459", defaultRound, 100, 'f', 2, "3.46"},
+ {"4.459", defaultRound, 100, 'f', 3, "4.459"},
+ {"5.459", defaultRound, 100, 'f', 4, "5.4590"},
+
+ {"1.459", defaultRound, 100, 'g', 0, "1"},
+ {"2.459", defaultRound, 100, 'g', 1, "2"},
+ {"3.459", defaultRound, 100, 'g', 2, "3.5"},
+ {"4.459", defaultRound, 100, 'g', 3, "4.46"},
+ {"5.459", defaultRound, 100, 'g', 4, "5.459"},
+
+ {"1459", defaultRound, 53, 'g', 0, "1e+03"},
+ {"2459", defaultRound, 53, 'g', 1, "2e+03"},
+ {"3459", defaultRound, 53, 'g', 2, "3.5e+03"},
+ {"4459", defaultRound, 53, 'g', 3, "4.46e+03"},
+ {"5459", defaultRound, 53, 'g', 4, "5459"},
+
+ {"1459", defaultRound, 53, 'G', 0, "1E+03"},
+ {"2459", defaultRound, 53, 'G', 1, "2E+03"},
+ {"3459", defaultRound, 53, 'G', 2, "3.5E+03"},
+ {"4459", defaultRound, 53, 'G', 3, "4.46E+03"},
+ {"5459", defaultRound, 53, 'G', 4, "5459"},
+
+ {"3", defaultRound, 10, 'e', 40, "3.0000000000000000000000000000000000000000e+00"},
+ {"3", defaultRound, 10, 'f', 40, "3.0000000000000000000000000000000000000000"},
+ {"3", defaultRound, 10, 'g', 40, "3"},
+
+ {"3e40", defaultRound, 100, 'e', 40, "3.0000000000000000000000000000000000000000e+40"},
+ {"3e40", defaultRound, 100, 'f', 4, "30000000000000000000000000000000000000000.0000"},
+ {"3e40", defaultRound, 100, 'g', 40, "3e+40"},
+
+ // make sure "stupid" exponents don't stall the machine
+ {"1e1000000", defaultRound, 64, 'p', 0, "0x.88b3a28a05eade3ap+3321929"},
+ {"1e646456992", defaultRound, 64, 'p', 0, "0x.e883a0c5c8c7c42ap+2147483644"},
+ {"1e646456993", defaultRound, 64, 'p', 0, "+Inf"},
+ {"1e1000000000", defaultRound, 64, 'p', 0, "+Inf"},
+ {"1e-1000000", defaultRound, 64, 'p', 0, "0x.efb4542cc8ca418ap-3321928"},
+ {"1e-646456993", defaultRound, 64, 'p', 0, "0x.e17c8956983d9d59p-2147483647"},
+ {"1e-646456994", defaultRound, 64, 'p', 0, "0"},
+ {"1e-1000000000", defaultRound, 64, 'p', 0, "0"},
+
+ // minimum and maximum values
+ {"1p2147483646", defaultRound, 64, 'p', 0, "0x.8p+2147483647"},
+ {"0x.8p2147483647", defaultRound, 64, 'p', 0, "0x.8p+2147483647"},
+ {"0x.8p-2147483647", defaultRound, 64, 'p', 0, "0x.8p-2147483647"},
+ {"1p-2147483649", defaultRound, 64, 'p', 0, "0x.8p-2147483648"},
+
+ // TODO(gri) need tests for actual large Floats
+
+ {"0", defaultRound, 53, 'b', 0, "0"},
+ {"-0", defaultRound, 53, 'b', 0, "-0"},
+ {"1.0", defaultRound, 53, 'b', 0, "4503599627370496p-52"},
+ {"-1.0", defaultRound, 53, 'b', 0, "-4503599627370496p-52"},
+ {"4503599627370496", defaultRound, 53, 'b', 0, "4503599627370496p+0"},
+
+ // issue 9939
+ {"3", defaultRound, 350, 'b', 0, "1720123961992553633708115671476565205597423741876210842803191629540192157066363606052513914832594264915968p-348"},
+ {"03", defaultRound, 350, 'b', 0, "1720123961992553633708115671476565205597423741876210842803191629540192157066363606052513914832594264915968p-348"},
+ {"3.", defaultRound, 350, 'b', 0, "1720123961992553633708115671476565205597423741876210842803191629540192157066363606052513914832594264915968p-348"},
+ {"3.0", defaultRound, 350, 'b', 0, "1720123961992553633708115671476565205597423741876210842803191629540192157066363606052513914832594264915968p-348"},
+ {"3.00", defaultRound, 350, 'b', 0, "1720123961992553633708115671476565205597423741876210842803191629540192157066363606052513914832594264915968p-348"},
+ {"3.000", defaultRound, 350, 'b', 0, "1720123961992553633708115671476565205597423741876210842803191629540192157066363606052513914832594264915968p-348"},
+
+ {"3", defaultRound, 350, 'p', 0, "0x.cp+2"},
+ {"03", defaultRound, 350, 'p', 0, "0x.cp+2"},
+ {"3.", defaultRound, 350, 'p', 0, "0x.cp+2"},
+ {"3.0", defaultRound, 350, 'p', 0, "0x.cp+2"},
+ {"3.00", defaultRound, 350, 'p', 0, "0x.cp+2"},
+ {"3.000", defaultRound, 350, 'p', 0, "0x.cp+2"},
+
+ {"0", defaultRound, 64, 'p', 0, "0"},
+ {"-0", defaultRound, 64, 'p', 0, "-0"},
+ {"1024.0", defaultRound, 64, 'p', 0, "0x.8p+11"},
+ {"-1024.0", defaultRound, 64, 'p', 0, "-0x.8p+11"},
+
+ {"0", defaultRound, 64, 'x', -1, "0x0p+00"},
+ {"0", defaultRound, 64, 'x', 0, "0x0p+00"},
+ {"0", defaultRound, 64, 'x', 1, "0x0.0p+00"},
+ {"0", defaultRound, 64, 'x', 5, "0x0.00000p+00"},
+ {"3.25", defaultRound, 64, 'x', 0, "0x1p+02"},
+ {"-3.25", defaultRound, 64, 'x', 0, "-0x1p+02"},
+ {"3.25", defaultRound, 64, 'x', 1, "0x1.ap+01"},
+ {"-3.25", defaultRound, 64, 'x', 1, "-0x1.ap+01"},
+ {"3.25", defaultRound, 64, 'x', -1, "0x1.ap+01"},
+ {"-3.25", defaultRound, 64, 'x', -1, "-0x1.ap+01"},
+ {"1024.0", defaultRound, 64, 'x', 0, "0x1p+10"},
+ {"-1024.0", defaultRound, 64, 'x', 0, "-0x1p+10"},
+ {"1024.0", defaultRound, 64, 'x', 5, "0x1.00000p+10"},
+ {"8191.0", defaultRound, 53, 'x', -1, "0x1.fffp+12"},
+ {"8191.5", defaultRound, 53, 'x', -1, "0x1.fff8p+12"},
+ {"8191.53125", defaultRound, 53, 'x', -1, "0x1.fff88p+12"},
+ {"8191.53125", defaultRound, 53, 'x', 4, "0x1.fff8p+12"},
+ {"8191.53125", defaultRound, 53, 'x', 3, "0x1.000p+13"},
+ {"8191.53125", defaultRound, 53, 'x', 0, "0x1p+13"},
+ {"8191.533203125", defaultRound, 53, 'x', -1, "0x1.fff888p+12"},
+ {"8191.533203125", defaultRound, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.533203125", defaultRound, 53, 'x', 4, "0x1.fff9p+12"},
+
+ {"8191.53125", defaultRound, 53, 'x', -1, "0x1.fff88p+12"},
+ {"8191.53125", ToNearestEven, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.53125", ToNearestAway, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.53125", ToZero, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.53125", AwayFromZero, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.53125", ToNegativeInf, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.53125", ToPositiveInf, 53, 'x', 5, "0x1.fff88p+12"},
+
+ {"8191.53125", defaultRound, 53, 'x', 4, "0x1.fff8p+12"},
+ {"8191.53125", defaultRound, 53, 'x', 3, "0x1.000p+13"},
+ {"8191.53125", defaultRound, 53, 'x', 0, "0x1p+13"},
+ {"8191.533203125", defaultRound, 53, 'x', -1, "0x1.fff888p+12"},
+ {"8191.533203125", defaultRound, 53, 'x', 6, "0x1.fff888p+12"},
+ {"8191.533203125", defaultRound, 53, 'x', 5, "0x1.fff88p+12"},
+ {"8191.533203125", defaultRound, 53, 'x', 4, "0x1.fff9p+12"},
+
+ {"8191.53125", ToNearestEven, 53, 'x', 4, "0x1.fff8p+12"},
+ {"8191.53125", ToNearestAway, 53, 'x', 4, "0x1.fff9p+12"},
+ {"8191.53125", ToZero, 53, 'x', 4, "0x1.fff8p+12"},
+ {"8191.53125", ToZero, 53, 'x', 2, "0x1.ffp+12"},
+ {"8191.53125", AwayFromZero, 53, 'x', 4, "0x1.fff9p+12"},
+ {"8191.53125", ToNegativeInf, 53, 'x', 4, "0x1.fff8p+12"},
+ {"-8191.53125", ToNegativeInf, 53, 'x', 4, "-0x1.fff9p+12"},
+ {"8191.53125", ToPositiveInf, 53, 'x', 4, "0x1.fff9p+12"},
+ {"-8191.53125", ToPositiveInf, 53, 'x', 4, "-0x1.fff8p+12"},
+
+ // issue 34343
+ {"0x.8p-2147483648", ToNearestEven, 4, 'p', -1, "0x.8p-2147483648"},
+ {"0x.8p-2147483648", ToNearestEven, 4, 'x', -1, "0x1p-2147483649"},
+ } {
+ f, _, err := ParseFloat(test.x, 0, test.prec, ToNearestEven)
+ if err != nil {
+ t.Errorf("%v: %s", test, err)
+ continue
+ }
+ if test.round != defaultRound {
+ f.SetMode(test.round)
+ }
+
+ got := f.Text(test.format, test.digits)
+ if got != test.want {
+ t.Errorf("%v: got %s; want %s", test, got, test.want)
+ }
+
+ // compare with strconv.FormatFloat output if possible
+ // ('p' format is not supported by strconv.FormatFloat,
+ // and its output for 0.0 prints a biased exponent value
+ // as in 0p-1074 which makes no sense to emulate here)
+ if test.prec == 53 && test.format != 'p' && f.Sign() != 0 && (test.round == ToNearestEven || test.round == defaultRound) {
+ f64, acc := f.Float64()
+ if acc != Exact {
+ t.Errorf("%v: expected exact conversion to float64", test)
+ continue
+ }
+ got := strconv.FormatFloat(f64, test.format, test.digits, 64)
+ if got != test.want {
+ t.Errorf("%v: got %s; want %s", test, got, test.want)
+ }
+ }
+ }
+}
+
+func TestFloatFormat(t *testing.T) {
+ for _, test := range []struct {
+ format string
+ value any // float32, float64, or string (== 512bit *Float)
+ want string
+ }{
+ // from fmt/fmt_test.go
+ {"%+.3e", 0.0, "+0.000e+00"},
+ {"%+.3e", 1.0, "+1.000e+00"},
+ {"%+.3f", -1.0, "-1.000"},
+ {"%+.3F", -1.0, "-1.000"},
+ {"%+.3F", float32(-1.0), "-1.000"},
+ {"%+07.2f", 1.0, "+001.00"},
+ {"%+07.2f", -1.0, "-001.00"},
+ {"%+10.2f", +1.0, " +1.00"},
+ {"%+10.2f", -1.0, " -1.00"},
+ {"% .3E", -1.0, "-1.000E+00"},
+ {"% .3e", 1.0, " 1.000e+00"},
+ {"%+.3g", 0.0, "+0"},
+ {"%+.3g", 1.0, "+1"},
+ {"%+.3g", -1.0, "-1"},
+ {"% .3g", -1.0, "-1"},
+ {"% .3g", 1.0, " 1"},
+ {"%b", float32(1.0), "8388608p-23"},
+ {"%b", 1.0, "4503599627370496p-52"},
+
+ // from fmt/fmt_test.go: old test/fmt_test.go
+ {"%e", 1.0, "1.000000e+00"},
+ {"%e", 1234.5678e3, "1.234568e+06"},
+ {"%e", 1234.5678e-8, "1.234568e-05"},
+ {"%e", -7.0, "-7.000000e+00"},
+ {"%e", -1e-9, "-1.000000e-09"},
+ {"%f", 1234.5678e3, "1234567.800000"},
+ {"%f", 1234.5678e-8, "0.000012"},
+ {"%f", -7.0, "-7.000000"},
+ {"%f", -1e-9, "-0.000000"},
+ {"%g", 1234.5678e3, "1.2345678e+06"},
+ {"%g", float32(1234.5678e3), "1.2345678e+06"},
+ {"%g", 1234.5678e-8, "1.2345678e-05"},
+ {"%g", -7.0, "-7"},
+ {"%g", -1e-9, "-1e-09"},
+ {"%g", float32(-1e-9), "-1e-09"},
+ {"%E", 1.0, "1.000000E+00"},
+ {"%E", 1234.5678e3, "1.234568E+06"},
+ {"%E", 1234.5678e-8, "1.234568E-05"},
+ {"%E", -7.0, "-7.000000E+00"},
+ {"%E", -1e-9, "-1.000000E-09"},
+ {"%G", 1234.5678e3, "1.2345678E+06"},
+ {"%G", float32(1234.5678e3), "1.2345678E+06"},
+ {"%G", 1234.5678e-8, "1.2345678E-05"},
+ {"%G", -7.0, "-7"},
+ {"%G", -1e-9, "-1E-09"},
+ {"%G", float32(-1e-9), "-1E-09"},
+
+ {"%20.6e", 1.2345e3, " 1.234500e+03"},
+ {"%20.6e", 1.2345e-3, " 1.234500e-03"},
+ {"%20e", 1.2345e3, " 1.234500e+03"},
+ {"%20e", 1.2345e-3, " 1.234500e-03"},
+ {"%20.8e", 1.2345e3, " 1.23450000e+03"},
+ {"%20f", 1.23456789e3, " 1234.567890"},
+ {"%20f", 1.23456789e-3, " 0.001235"},
+ {"%20f", 12345678901.23456789, " 12345678901.234568"},
+ {"%-20f", 1.23456789e3, "1234.567890 "},
+ {"%20.8f", 1.23456789e3, " 1234.56789000"},
+ {"%20.8f", 1.23456789e-3, " 0.00123457"},
+ {"%g", 1.23456789e3, "1234.56789"},
+ {"%g", 1.23456789e-3, "0.00123456789"},
+ {"%g", 1.23456789e20, "1.23456789e+20"},
+ {"%20e", math.Inf(1), " +Inf"},
+ {"%-20f", math.Inf(-1), "-Inf "},
+
+ // from fmt/fmt_test.go: comparison of padding rules with C printf
+ {"%.2f", 1.0, "1.00"},
+ {"%.2f", -1.0, "-1.00"},
+ {"% .2f", 1.0, " 1.00"},
+ {"% .2f", -1.0, "-1.00"},
+ {"%+.2f", 1.0, "+1.00"},
+ {"%+.2f", -1.0, "-1.00"},
+ {"%7.2f", 1.0, " 1.00"},
+ {"%7.2f", -1.0, " -1.00"},
+ {"% 7.2f", 1.0, " 1.00"},
+ {"% 7.2f", -1.0, " -1.00"},
+ {"%+7.2f", 1.0, " +1.00"},
+ {"%+7.2f", -1.0, " -1.00"},
+ {"%07.2f", 1.0, "0001.00"},
+ {"%07.2f", -1.0, "-001.00"},
+ {"% 07.2f", 1.0, " 001.00"},
+ {"% 07.2f", -1.0, "-001.00"},
+ {"%+07.2f", 1.0, "+001.00"},
+ {"%+07.2f", -1.0, "-001.00"},
+
+ // from fmt/fmt_test.go: zero padding does not apply to infinities
+ {"%020f", math.Inf(-1), " -Inf"},
+ {"%020f", math.Inf(+1), " +Inf"},
+ {"% 020f", math.Inf(-1), " -Inf"},
+ {"% 020f", math.Inf(+1), " Inf"},
+ {"%+020f", math.Inf(-1), " -Inf"},
+ {"%+020f", math.Inf(+1), " +Inf"},
+ {"%20f", -1.0, " -1.000000"},
+
+ // handle %v like %g
+ {"%v", 0.0, "0"},
+ {"%v", -7.0, "-7"},
+ {"%v", -1e-9, "-1e-09"},
+ {"%v", float32(-1e-9), "-1e-09"},
+ {"%010v", 0.0, "0000000000"},
+
+ // *Float cases
+ {"%.20f", "1e-20", "0.00000000000000000001"},
+ {"%.20f", "-1e-20", "-0.00000000000000000001"},
+ {"%30.20f", "-1e-20", " -0.00000000000000000001"},
+ {"%030.20f", "-1e-20", "-00000000.00000000000000000001"},
+ {"%030.20f", "+1e-20", "000000000.00000000000000000001"},
+ {"% 030.20f", "+1e-20", " 00000000.00000000000000000001"},
+
+ // erroneous formats
+ {"%s", 1.0, "%!s(*big.Float=1)"},
+ } {
+ value := new(Float)
+ switch v := test.value.(type) {
+ case float32:
+ value.SetPrec(24).SetFloat64(float64(v))
+ case float64:
+ value.SetPrec(53).SetFloat64(v)
+ case string:
+ value.SetPrec(512).Parse(v, 0)
+ default:
+ t.Fatalf("unsupported test value: %v (%T)", v, v)
+ }
+
+ if got := fmt.Sprintf(test.format, value); got != test.want {
+ t.Errorf("%v: got %q; want %q", test, got, test.want)
+ }
+ }
+}
+
+func BenchmarkParseFloatSmallExp(b *testing.B) {
+ for i := 0; i < b.N; i++ {
+ for _, s := range []string{
+ "1e0",
+ "1e-1",
+ "1e-2",
+ "1e-3",
+ "1e-4",
+ "1e-5",
+ "1e-10",
+ "1e-20",
+ "1e-50",
+ "1e1",
+ "1e2",
+ "1e3",
+ "1e4",
+ "1e5",
+ "1e10",
+ "1e20",
+ "1e50",
+ } {
+ var x Float
+ _, _, err := x.Parse(s, 0)
+ if err != nil {
+ b.Fatalf("%s: %v", s, err)
+ }
+ }
+ }
+}
+
+func BenchmarkParseFloatLargeExp(b *testing.B) {
+ for i := 0; i < b.N; i++ {
+ for _, s := range []string{
+ "1e0",
+ "1e-10",
+ "1e-20",
+ "1e-30",
+ "1e-40",
+ "1e-50",
+ "1e-100",
+ "1e-500",
+ "1e-1000",
+ "1e-5000",
+ "1e-10000",
+ "1e10",
+ "1e20",
+ "1e30",
+ "1e40",
+ "1e50",
+ "1e100",
+ "1e500",
+ "1e1000",
+ "1e5000",
+ "1e10000",
+ } {
+ var x Float
+ _, _, err := x.Parse(s, 0)
+ if err != nil {
+ b.Fatalf("%s: %v", s, err)
+ }
+ }
+ }
+}
+
+func TestFloatScan(t *testing.T) {
+ var floatScanTests = []struct {
+ input string
+ format string
+ output string
+ remaining int
+ wantErr bool
+ }{
+ 0: {"10.0", "%f", "10", 0, false},
+ 1: {"23.98+2.0", "%v", "23.98", 4, false},
+ 2: {"-1+1", "%v", "-1", 2, false},
+ 3: {" 00000", "%v", "0", 0, false},
+ 4: {"-123456p-78", "%b", "-4.084816388e-19", 0, false},
+ 5: {"+123", "%b", "123", 0, false},
+ 6: {"-1.234e+56", "%e", "-1.234e+56", 0, false},
+ 7: {"-1.234E-56", "%E", "-1.234e-56", 0, false},
+ 8: {"-1.234e+567", "%g", "-1.234e+567", 0, false},
+ 9: {"+1234567891011.234", "%G", "1.234567891e+12", 0, false},
+
+ // Scan doesn't handle ±Inf.
+ 10: {"Inf", "%v", "", 3, true},
+ 11: {"-Inf", "%v", "", 3, true},
+ 12: {"-Inf", "%v", "", 3, true},
+ }
+
+ var buf bytes.Buffer
+ for i, test := range floatScanTests {
+ x := new(Float)
+ buf.Reset()
+ buf.WriteString(test.input)
+ _, err := fmt.Fscanf(&buf, test.format, x)
+ if test.wantErr {
+ if err == nil {
+ t.Errorf("#%d want non-nil err", i)
+ }
+ continue
+ }
+
+ if err != nil {
+ t.Errorf("#%d error: %s", i, err)
+ }
+
+ if x.String() != test.output {
+ t.Errorf("#%d got %s; want %s", i, x.String(), test.output)
+ }
+ if buf.Len() != test.remaining {
+ t.Errorf("#%d got %d bytes remaining; want %d", i, buf.Len(), test.remaining)
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 21:18:08 +0000