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

// Differential kernel for the arm64 integer slice: carry-setting arithmetic,
// widening multiplies, bit manipulation, conditional compares, the compare
// and test branches, ADR and the wide-constant moves.  Every function is
// byte-compared against go tool asm.

#include "textflag.h"

// func carryArith()
TEXT ·carryArith(SB), NOSPLIT, $0-0
	ADC  R0, R2, R12
	ADCS R23, R22, R22
	ADC  $0, R1
	SBC  R25, R10, R26
	SBCS R5, R9, R5
	SBCS $0, R1
	RET

// func wideningMul()
TEXT ·wideningMul(SB), NOSPLIT, $0-0
	MUL   R4, R3, R0
	MSUB  R19, R16, R26, R2
	SMULH R24, R20, R24
	UMULH R24, R20, R24
	RET

// func bitManip()
TEXT ·bitManip(SB), NOSPLIT, $0-0
	RBIT  R11, R4
	REV   R1, R2
	CLZ   R21, R9
	REVW  R1, R2
	CLSW  R1, R2
	UBFX  $33, R17, $25, R5
	UBFXW $4, R1, $9, R2
	RET

// func condCompare()
TEXT ·condCompare(SB), NOSPLIT, $0-0
	CCMP  LE, R7, $19, $3
	CCMP  LT, R30, R6, $7
	CCMN  EQ, R1, R2, $3
	CCMPW LE, R7, $19, $3
	RET

// func branchForms()
TEXT ·branchForms(SB), NOSPLIT, $0-0
	CBZ   R1, target
	CBNZ  R7, target
	CBNZW R2, target
	TBZ   $4, R7, target
	TBNZ  $33, R7, target
	ADR   target, R10

target:
	RET

// func wideMoves()
TEXT ·wideMoves(SB), NOSPLIT, $0-0
	MOVK  $1234, R5
	MOVK  $305397760, R5
	MOVKW $1234, R5
	MOVK  $16771847290880, R21
	RET