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// Copyright 2022 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.
#include "textflag.h"
// func Syscall6(num, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, errno uintptr)
//
// We need to convert to the syscall ABI.
//
// arg | ABIInternal | Syscall
// ---------------------------
// num | AX | AX
// a1 | BX | DI
// a2 | CX | SI
// a3 | DI | DX
// a4 | SI | R10
// a5 | R8 | R8
// a6 | R9 | R9
//
// r1 | AX | AX
// r2 | BX | DX
// err | CX | part of AX
//
// Note that this differs from "standard" ABI convention, which would pass 4th
// arg in CX, not R10.
TEXT ·Syscall6<ABIInternal>(SB),NOSPLIT,$0
// a6 already in R9.
// a5 already in R8.
MOVQ SI, R10 // a4
MOVQ DI, DX // a3
MOVQ CX, SI // a2
MOVQ BX, DI // a1
// num already in AX.
SYSCALL
CMPQ AX, $0xfffffffffffff001
JLS ok
NEGQ AX
MOVQ AX, CX // errno
MOVQ $-1, AX // r1
MOVQ $0, BX // r2
RET
ok:
// r1 already in AX.
MOVQ DX, BX // r2
MOVQ $0, CX // errno
RET
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