"unsafe"
	_ "unsafe" // for go:linkname
)

// OS-specific startup can set startupRand if the OS passes
// random data to the process at startup time.
// For example Linux passes 16 bytes in the auxv vector.
var startupRand []byte

// globalRand holds the global random state.
// It is only used at startup and for creating new m's.
// Otherwise the per-m random state should be used
// by calling goodrand.

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

//go:build !math_big_pure_go

#include "textflag.h"

// This file provides fast assembly versions for the elementary
// arithmetic operations on vectors implemented in arith.go.

// func addVV(z, x, y []Word) (c Word)
TEXT ·addVV(SB),NOSPLIT,$0
	MOVL z+0(FP), DI
	MOVL x+12(FP), SI
	MOVL y+24(FP), CX
	MOVL z_len+4(FP), BP
	MOVL $0, BX		// i = 0

}

// Add returns the vector p+q.
func (p Point) Add(q Point) Point {
	return Point{p.X + q.X, p.Y + q.Y}
}

// Sub returns the vector p-q.
func (p Point) Sub(q Point) Point {
	return Point{p.X - q.X, p.Y - q.Y}
}

// Mul returns the vector p*k.
func (p Point) Mul(k int) Point {
	return Point{p.X * k, p.Y * k}
}

// Div returns the vector p/k.
func (p Point) Div(k int) Point {

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

//go:build !math_big_pure_go

#include "textflag.h"

// This file provides fast assembly versions for the elementary
// arithmetic operations on vectors implemented in arith.go.

// func addVV(z, x, y []Word) (c Word)
TEXT ·addVV(SB),NOSPLIT,$0
	ADD.S	$0, R0		// clear carry flag
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R4
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3

	BLT	tail		// Jump to the small string case
	SRD	$5, R4, R20
	MOVD	R20, CTR
	MOVD	$16, R21
	XXLXOR	V4, V4, V4
	XXLXOR	V5, V5, V5

	PCALIGN	$16
cmploop:
	LXVD2X	(R0)(R3), V0	// Count 32B per loop with two vector accumulators.
	LXVD2X	(R21)(R3), V2
	VCMPEQUB V2, V1, V2
	VCMPEQUB V0, V1, V0
	VPOPCNTD V2, V2		// A match is 0xFF or 0. Count the bits into doubleword buckets.
	VPOPCNTD V0, V0

	MOVL (AX)(X0*1), AX             // ERROR "invalid instruction"
	MOVL (AX)(Y0*1), AX             // ERROR "invalid instruction"
	// VSIB/VM is invalid without vector index.
	// TODO(quasilyte): improve error message (#21860).
	// "invalid VSIB address (missing vector index)"
	VPGATHERQQ Y2, (BP), Y1         // ERROR "invalid instruction"
	// AVX2GATHER mask/index/dest #UD cases.

	// Create a struct callbackArgs on our stack.
	MOVD	$cbargs-(18*8+callbackArgs__size)(SP), R13
	MOVD	R12, callbackArgs_index(R13)	// callback index
	MOVD	R14, R0
	MOVD	R0, callbackArgs_args(R13)		// address of args vector
	MOVD	$0, R0
	MOVD	R0, callbackArgs_result(R13)	// result

	// Call cgocallback, which will call callbackWrap(frame).

type ofb struct {
	b       Block
	cipher  []byte
	out     []byte
	outUsed int
}

// NewOFB returns a [Stream] that encrypts or decrypts using the block cipher b
// in output feedback mode. The initialization vector iv's length must be equal
// to b's block size.
func NewOFB(b Block, iv []byte) Stream {
	blockSize := b.BlockSize()
	if len(iv) != blockSize {
		panic("cipher.NewOFB: IV length must equal block size")
	}

	// Create a struct callbackArgs on our stack.
	MOVW	R12, (16+callbackArgs_index)(R13)	// callback index
	MOVW	$(16+callbackArgs__size+4*9)(R13), R0
	MOVW	R0, (16+callbackArgs_args)(R13)		// address of args vector
	MOVW	$0, R0
	MOVW	R0, (16+callbackArgs_result)(R13)	// result

	// Prepare for entry to Go.
	BL	runtime·load_g(SB)

	// Call cgocallback, which will call callbackWrap(frame).
	MOVW	$0, R0

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

//go:build !math_big_pure_go

#include "textflag.h"

// This file provides fast assembly versions for the elementary
// arithmetic operations on vectors implemented in arith.go.

// The carry bit is saved with SBBQ Rx, Rx: if the carry was set, Rx is -1, otherwise it is 0.
// It is restored with ADDQ Rx, Rx: if Rx was -1 the carry is set, otherwise it is cleared.