ending:
	RET

zero_exact_16:
	// n is exactly 16 bytes
	STP	(ZR, ZR), (R0)
	RET

zero_by_16:
	// n greater than 16 bytes, check if the start address is aligned
	NEG	R0, R4
	ANDS	$15, R4, R4
	// Try zeroing using zva if the start address is aligned with 16
	BEQ	try_zva

	// Non-aligned store
	STP	(ZR, ZR), (R0)
	// Make the destination aligned
	SUB	R4, R1, R1
	ADD	R4, R0, R0
	B	try_zva

tail_maybe_long:

// the stack frame in certain specific circumstances.
//
// In the current compiler implementation, for zerorange to be
// invoked, we need to have an ambiguously live variable that needs
// zeroing. One way to trigger this is to have a function with an
// open-coded defer, where the opendefer function has an argument that
// contains a pointer (this is what's used below).
//

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

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.

	REG_AR14
	REG_AR15

	REG_RESERVED // end of allocated registers

	REGARG  = -1      // -1 disables passing the first argument in register
	REGRT1  = REG_R3  // used during zeroing of the stack - not reserved
	REGRT2  = REG_R4  // used during zeroing of the stack - not reserved
	REGTMP  = REG_R10 // scratch register used in the assembler and linker
	REGTMP2 = REG_R11 // scratch register used in the assembler and linker

	var to unsafe.Pointer
	if !et.Pointers() {
		to = mallocgc(tomem, nil, false)
		if copymem < tomem {
			memclrNoHeapPointers(add(to, copymem), tomem-copymem)
		}
	} else {
		// Note: can't use rawmem (which avoids zeroing of memory), because then GC can scan uninitialized memory.
		to = mallocgc(tomem, et, true)
		if copymem > 0 && writeBarrier.enabled {
			// Only shade the pointers in old.array since we know the destination slice to

func (d *state) BlockSize() int { return d.rate }

// Size returns the output size of the hash function in bytes.
func (d *state) Size() int { return d.outputLen }

// Reset clears the internal state by zeroing the sponge state and
// the buffer indexes, and setting Sponge.state to absorbing.
func (d *state) Reset() {
	// Zero the permutation's state.
	for i := range d.a {
		d.a[i] = 0
	}
	d.state = spongeAbsorbing

		(I64Store32 destptr (I64Const [0]) mem))
(Zero [7] destptr mem) =>
	(I64Store32 [3] destptr (I64Const [0])
		(I64Store32 destptr (I64Const [0]) mem))

// Strip off any fractional word zeroing.
(Zero [s] destptr mem) && s%8 != 0 && s > 8 && s < 32 =>
	(Zero [s-s%8] (OffPtr <destptr.Type> destptr [s%8])
		(I64Store destptr (I64Const [0]) mem))

// Zero small numbers of words directly.

	// this is a case that the frontend failed to eliminate.
	p := &y
	*p = x // no barrier
	return
}

type T23 struct {
	p *int
	a int
}

var t23 T23
var i23 int

// f23x: zeroing global needs write barrier for the hybrid barrier.
func f23a() {
	t23 = T23{} // ERROR "write barrier"
}

func f23b() {
	// also test partial assignments
	t23 = T23{a: 1} // ERROR "write barrier"
}

	if goexperiment.CgoCheck2 {
		cgoCheckMemmove2(typ, dst, src, 0, typ.Size_)
	}
}

// wbZero performs the write barrier operations necessary before
// zeroing a region of memory at address dst of type typ.
// Does not actually do the zeroing.
//
//go:nowritebarrierrec
//go:nosplit
func wbZero(typ *_type, dst unsafe.Pointer) {
	// This always copies a full value of type typ so it's safe

	fn := typecheck.LookupRuntime("mapclear", t.Key(), t.Elem())
	n := mkcallstmt1(fn, rtyp, m)
	return walkStmt(typecheck.Stmt(n))
}

// Lower n into runtime·memclr if possible, for
// fast zeroing of slices and arrays (issue 5373).
// Look for instances of
//
//	for i := range a {
//		a[i] = zero
//	}
//
// in which the evaluation of a is side-effect-free.
//