1// Copyright 2022 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "textflag.h"
6
7// func Syscall6(num, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, errno uintptr)
8//
9// We need to convert to the syscall ABI.
10//
11// arg | ABIInternal | Syscall
12// ---------------------------
13// num | R4 | R11
14// a1 | R5 | R4
15// a2 | R6 | R5
16// a3 | R7 | R6
17// a4 | R8 | R7
18// a5 | R9 | R8
19// a6 | R10 | R9
20//
21// r1 | R4 | R4
22// r2 | R5 | R5
23// err | R6 | part of R4
24TEXT ·Syscall6<ABIInternal>(SB),NOSPLIT,$0-80
25#ifdef GOEXPERIMENT_regabiargs
26 MOVV R4, R11 // syscall entry
27 MOVV R5, R4
28 MOVV R6, R5
29 MOVV R7, R6
30 MOVV R8, R7
31 MOVV R9, R8
32 MOVV R10, R9
33#else
34 MOVV num+0(FP), R11 // syscall entry
35 MOVV a1+8(FP), R4
36 MOVV a2+16(FP), R5
37 MOVV a3+24(FP), R6
38 MOVV a4+32(FP), R7
39 MOVV a5+40(FP), R8
40 MOVV a6+48(FP), R9
41#endif
42 SYSCALL
43#ifdef GOEXPERIMENT_regabiargs
44 MOVV R0, R5 // r2 is not used. Always set to 0.
45 MOVW $-4096, R12
46 BGEU R12, R4, ok
47 SUBVU R4, R0, R6 // errno
48 MOVV $-1, R4 // r1
49#else
50 MOVW $-4096, R12
51 BGEU R12, R4, ok
52 MOVV $-1, R12
53 MOVV R12, r1+56(FP)
54 MOVV R0, r2+64(FP)
55 SUBVU R4, R0, R4
56 MOVV R4, errno+72(FP)
57#endif
58 RET
59ok:
60#ifdef GOEXPERIMENT_regabiargs
61 // r1 already in R4
62 MOVV R0, R6 // errno
63#else
64 MOVV R4, r1+56(FP)
65 MOVV R0, r2+64(FP) // r2 is not used. Always set to 0.
66 MOVV R0, errno+72(FP)
67#endif
68 RET
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