mirror of
https://github.com/golang/go
synced 2024-11-13 17:50:23 -07:00
c12e1b0b2e
This makes the rounding bug fix in math/big for issue 14651 available to the compiler. - changes to cmd/compile/internal/big fully automatic via script - added test case for issue - updated old test case with correct test data Fixes #14651. Change-Id: Iea37a2cd8d3a75f8c96193748b66156a987bbe40 Reviewed-on: https://go-review.googlesource.com/20818 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
// run
|
|
|
|
// 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.
|
|
|
|
// This test checks if the compiler's internal constant
|
|
// arithmetic correctly rounds up floating-point values
|
|
// that become the smallest denormal value.
|
|
//
|
|
// See also related issue 14553 and test issue14553.go.
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"math"
|
|
)
|
|
|
|
const (
|
|
p149 = 1.0 / (1 << 149) // 1p-149
|
|
p500 = 1.0 / (1 << 500) // 1p-500
|
|
p1074 = p500 * p500 / (1<<74) // 1p-1074
|
|
)
|
|
|
|
const (
|
|
m0000p149 = 0x0 / 16.0 * p149 // = 0.0000p-149
|
|
m1000p149 = 0x8 / 16.0 * p149 // = 0.1000p-149
|
|
m1001p149 = 0x9 / 16.0 * p149 // = 0.1001p-149
|
|
m1011p149 = 0xb / 16.0 * p149 // = 0.1011p-149
|
|
m1100p149 = 0xc / 16.0 * p149 // = 0.1100p-149
|
|
|
|
m0000p1074 = 0x0 / 16.0 * p1074 // = 0.0000p-1074
|
|
m1000p1074 = 0x8 / 16.0 * p1074 // = 0.1000p-1074
|
|
m1001p1074 = 0x9 / 16.0 * p1074 // = 0.1001p-1074
|
|
m1011p1074 = 0xb / 16.0 * p1074 // = 0.1011p-1074
|
|
m1100p1074 = 0xc / 16.0 * p1074 // = 0.1100p-1074
|
|
)
|
|
|
|
func main() {
|
|
test32(float32(m0000p149), f32(m0000p149))
|
|
test32(float32(m1000p149), f32(m1000p149))
|
|
test32(float32(m1001p149), f32(m1001p149))
|
|
test32(float32(m1011p149), f32(m1011p149))
|
|
test32(float32(m1100p149), f32(m1100p149))
|
|
|
|
test64(float64(m0000p1074), f64(m0000p1074))
|
|
test64(float64(m1000p1074), f64(m1000p1074))
|
|
test64(float64(m1001p1074), f64(m1001p1074))
|
|
test64(float64(m1011p1074), f64(m1011p1074))
|
|
test64(float64(m1100p1074), f64(m1100p1074))
|
|
}
|
|
|
|
func f32(x float64) float32 { return float32(x) }
|
|
func f64(x float64) float64 { return float64(x) }
|
|
|
|
func test32(a, b float32) {
|
|
abits := math.Float32bits(a)
|
|
bbits := math.Float32bits(b)
|
|
if abits != bbits {
|
|
panic(fmt.Sprintf("%08x != %08x\n", abits, bbits))
|
|
}
|
|
}
|
|
|
|
func test64(a, b float64) {
|
|
abits := math.Float64bits(a)
|
|
bbits := math.Float64bits(b)
|
|
if abits != bbits {
|
|
panic(fmt.Sprintf("%016x != %016x\n", abits, bbits))
|
|
}
|
|
}
|