@CollectionSize.Require(absent = ZERO)
  public void testReplaceEntry_supportedPresent() {
    try {
      assertTrue(getMap().replace(k0(), v0(), v3()));
      expectReplacement(entry(k0(), v3()));
    } catch (ClassCastException tolerated) { // for ClassToInstanceMap
      expectUnchanged();
    }
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)

  @MapFeature.Require(ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeySupported() {
    initMapWithNullKey();
    expectContents(createArrayWithNullKey());
  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEYS)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyUnsupported() {
    try {
      initMapWithNullKey();

func isNaN[T Ordered](x T) bool {
	return x != x
}

// Or returns the first of its arguments that is not equal to the zero value.
// If no argument is non-zero, it returns the zero value.
func Or[T comparable](vals ...T) T {
	var zero T
	for _, val := range vals {
		if val != zero {
			return val
		}
	}
	return zero

package main

// untyped constant
const zero = 0

func main() {
	var x int
	_ = x
	x = make(map[int]int)       // ERROR "cannot use make\(map\[int\]int\)|incompatible"
	x = make(map[int]int, 0)    // ERROR "cannot use make\(map\[int\]int, 0\)|incompatible"
	x = make(map[int]int, zero) // ERROR "cannot use make\(map\[int\]int, zero\)|incompatible"

	MOV	a1+8(FP), A0
	MOV	a2+16(FP), A1
	MOV	a3+24(FP), A2
	MOV	ZERO, A3
	MOV	ZERO, A4
	MOV	ZERO, A5
	MOV	trap+0(FP), A7	// syscall entry
	ECALL
	MOV	$-4096, T0
	BLTU	T0, A0, err
	MOV	A0, r1+32(FP)	// r1
	MOV	ZERO, err+40(FP)	// errno
	RET
err:
	MOV	$-1, T0
	MOV	T0, r1+32(FP)	// r1
	SUB	A0, ZERO, A0
	MOV	A0, err+40(FP)	// errno
	RET

TEXT ·rawSyscallNoError(SB),NOSPLIT,$0-48

  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAll_allPresent() {
    assertTrue(
        "removeAll(intersectingCollection) should return true",
        collection.removeAll(MinimalCollection.of(e0())));
    expectMissing(e0());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAll_somePresent() {
    assertTrue(

	MOVW	off+28(FP), A5
	MOV	$SYS_mmap, T0
	ECALL
	BNE	T0, ZERO, fail
	MOV	A0, p+32(FP)
	MOV	ZERO, err+40(FP)
	RET
fail:
	MOV	ZERO, p+32(FP)
	MOV	A0, err+40(FP)
	RET

// func munmap(addr uintptr, n uintptr) (err error)
TEXT runtime·munmap(SB),NOSPLIT|NOFRAME,$0
	MOV	addr+0(FP), A0
	MOV	n+8(FP), A1
	MOV	$SYS_munmap, T0
	ECALL
	BNE	T0, ZERO, fail
	RET
fail:
	WORD	$0	// crash

		fmt.Fprintln(w)
	}
	fmt.Fprintln(w, "\tRET")
}

func zeroRISCV64(w io.Writer) {
	// ZERO: always zero
	// X25: ptr to memory to be zeroed
	// X25 is updated as a side effect.
	fmt.Fprintln(w, "TEXT runtime·duffzero<ABIInternal>(SB), NOSPLIT|NOFRAME, $0-0")
	for i := 0; i < 128; i++ {
		fmt.Fprintln(w, "\tMOV\tZERO, (X25)")
		fmt.Fprintln(w, "\tADD\t$8, X25")
	}
	fmt.Fprintln(w, "\tRET")
}

package main

import (
	"bytes"
	"fmt"
	"go/format"
	"log"
	"os"
)

// This program generates tests to verify that zeroing operations
// zero the data they are supposed to and clobber no adjacent values.

// run as `go run zeroGen.go`.  A file called zero.go
// will be written into the parent directory containing the tests.

// license that can be found in the LICENSE file.

package main

import "fmt"

func main() {
	IsZero[int](0)
}

func IsZero[T comparable](val T) bool {
	var zero T
	fmt.Printf("%v:%v\n", zero, val)
	return val != zero