// run

// Copyright 2015 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.

// Ensure that zeroing range loops have the requisite side-effects.

package main

import (
	"fmt"
	"os"
)

func check(n int) {
	// When n == 0, i is untouched by the range loop.
	// Picking an initial value of -1 for i makes the

		p = pp.Append(p, obj.ADUFFZERO, obj.TYPE_NONE, 0, 0, obj.TYPE_MEM, 0, 0)
		p.To.Name = obj.NAME_EXTERN
		p.To.Sym = ir.Syms.Duffzero
		p.To.Offset = 8 * (128 - cnt/int64(types.PtrSize))
		return p
	}

	// Loop, zeroing pointer width bytes at a time.
	// ADD	$(off), SP, T0
	// ADD	$(cnt), T0, T1
	// loop:
	// 	MOV	ZERO, (T0)
	// 	ADD	$Widthptr, T0
	//	BNE	T0, T1, loop

		h -= pow * uint32(s[i+n])
		if h == hashss && string(s[i:i+n]) == string(sep) {
			return i
		}
	}
	return -1
}

// MakeNoZero makes a slice of length n and capacity of at least n Bytes
// without zeroing the bytes (including the bytes between len and cap).
// It is the caller's responsibility to ensure uninitialized bytes
// do not leak to the end user.

// Malloc uses a FixAlloc wrapped around sysAlloc to manage its
// mcache and mspan objects.
//
// Memory returned by fixalloc.alloc is zeroed by default, but the
// caller may take responsibility for zeroing allocations by setting
// the zero flag to false. This is only safe if the memory never
// contains heap pointers.
//
// The caller is responsible for locking around FixAlloc calls.

func FilterInPlace[E any](s []E, f func(E) bool) []E {
	n := 0
	for _, val := range s {
		if f(val) {
			s[n] = val
			n++
		}
	}

	// If those elements contain pointers you might consider zeroing those elements
	// so that objects they reference can be garbage collected."
	var empty E
	for i := n; i < len(s); i++ {
		s[i] = empty
	}

	s = s[:n]
	return s
}

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.

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

	// 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"
}