diff options
Diffstat (limited to '')
-rw-r--r-- | src/runtime/minmax.go | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src/runtime/minmax.go b/src/runtime/minmax.go new file mode 100644 index 0000000..e5efc65 --- /dev/null +++ b/src/runtime/minmax.go @@ -0,0 +1,72 @@ +// 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 runtime + +import "unsafe" + +func strmin(x, y string) string { + if y < x { + return y + } + return x +} + +func strmax(x, y string) string { + if y > x { + return y + } + return x +} + +func fmin32(x, y float32) float32 { return fmin(x, y) } +func fmin64(x, y float64) float64 { return fmin(x, y) } +func fmax32(x, y float32) float32 { return fmax(x, y) } +func fmax64(x, y float64) float64 { return fmax(x, y) } + +type floaty interface{ ~float32 | ~float64 } + +func fmin[F floaty](x, y F) F { + if y != y || y < x { + return y + } + if x != x || x < y || x != 0 { + return x + } + // x and y are both ±0 + // if either is -0, return -0; else return +0 + return forbits(x, y) +} + +func fmax[F floaty](x, y F) F { + if y != y || y > x { + return y + } + if x != x || x > y || x != 0 { + return x + } + // x and y are both ±0 + // if both are -0, return -0; else return +0 + return fandbits(x, y) +} + +func forbits[F floaty](x, y F) F { + switch unsafe.Sizeof(x) { + case 4: + *(*uint32)(unsafe.Pointer(&x)) |= *(*uint32)(unsafe.Pointer(&y)) + case 8: + *(*uint64)(unsafe.Pointer(&x)) |= *(*uint64)(unsafe.Pointer(&y)) + } + return x +} + +func fandbits[F floaty](x, y F) F { + switch unsafe.Sizeof(x) { + case 4: + *(*uint32)(unsafe.Pointer(&x)) &= *(*uint32)(unsafe.Pointer(&y)) + case 8: + *(*uint64)(unsafe.Pointer(&x)) &= *(*uint64)(unsafe.Pointer(&y)) + } + return x +} |