// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause

// Differential kernel for the arm64 out-of-band offsets: the ADD/SUB into
// REGTMP for offsets within ±4095 no single instruction carries, and the
// 24-bit hi/lo split for the wide bands.  Every function is byte-compared
// against go tool asm.

#include "textflag.h"

// func bytes()
TEXT ·bytes(SB), NOSPLIT, $0-0
	MOVB R1, 4096(R2)
	MOVB R1, 8190(R2)
	MOVB R1, 65520(R2)
	MOVB R1, -4095(R2)
	MOVB 4096(R2), R1
	RET

// func halves()
TEXT ·halves(SB), NOSPLIT, $0-0
	MOVH R1, 16384(R2)
	MOVH R1, 16781310(R2)
	MOVH 0x2002(R1), R2
	MOVH R1, -4095(R2)
	RET

// func words()
TEXT ·words(SB), NOSPLIT, $0-0
	MOVW R1, 16388(R2)
	MOVW 0x4004(R1), R2
	MOVD R1, 4094(R2)
	MOVD R1, -300(R2)
	MOVD R1, 0x1006ff8(R2)
	MOVD 0x1006ff8(R1), R2
	FMOVS F1, 0x4004(R2)
	FMOVD F1, 0x1006ff8(R1)
	FMOVQ F1, 0x1003000(R2)
	RET

// func pairs()
TEXT ·pairs(SB), NOSPLIT, $0-0
	STP (R3, R4), 11(R0)
	STP (R3, R4), 1024(R0)
	STP (R3, R4), -4(R5)
	STP (R3, R4), 65536(R2)
	STPW (R3, R4), 1024(R0)
	LDP 11(R0), (R1, R2)
	LDP 1024(R0), (R1, R2)
	LDP -31(R0), (R1, R2)
	LDP 65536(R2), (R1, R2)
	LDPW -5(R0), (R1, R2)
	LDPSW 1024(R0), (R1, R2)
	FLDPD 1024(R0), (F1, F2)
	FLDPQ 1024(R0), (F1, F2)
	FLDPS 1024(R0), (F1, F2)
	RET