Initial commit: Go 1.23 release state

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
+}