1 // Copyright 2012 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 // Called by C code generated by cmd/cgo.
8 // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
9 // Saves C callee-saved registers and calls cgocallback with three arguments.
10 // fn is the PC of a func(a unsafe.Pointer) function.
11 TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
12 SUB $(8*9), R13 // Reserve space for the floating point registers.
13 // The C arguments arrive in R0, R1, R2, and R3. We want to
14 // pass R0, R1, and R3 to Go, so we push those on the stack.
15 // Also, save C callee-save registers R4-R12.
16 MOVM.WP [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12], (R13)
17 // Finally, save the link register R14. This also puts the
18 // arguments we pushed for cgocallback where they need to be,
19 // starting at 4(R13).
20 MOVW.W R14, -4(R13)
21
22 // Skip floating point registers on GOARM < 6.
23 MOVB runtime·goarm(SB), R11
24 CMP $6, R11
25 BLT skipfpsave
26 MOVD F8, (13*4+8*1)(R13)
27 MOVD F9, (13*4+8*2)(R13)
28 MOVD F10, (13*4+8*3)(R13)
29 MOVD F11, (13*4+8*4)(R13)
30 MOVD F12, (13*4+8*5)(R13)
31 MOVD F13, (13*4+8*6)(R13)
32 MOVD F14, (13*4+8*7)(R13)
33 MOVD F15, (13*4+8*8)(R13)
34
35 skipfpsave:
36 BL runtime·load_g(SB)
37 // We set up the arguments to cgocallback when saving registers above.
38 BL runtime·cgocallback(SB)
39
40 MOVB runtime·goarm(SB), R11
41 CMP $6, R11
42 BLT skipfprest
43 MOVD (13*4+8*1)(R13), F8
44 MOVD (13*4+8*2)(R13), F9
45 MOVD (13*4+8*3)(R13), F10
46 MOVD (13*4+8*4)(R13), F11
47 MOVD (13*4+8*5)(R13), F12
48 MOVD (13*4+8*6)(R13), F13
49 MOVD (13*4+8*7)(R13), F14
50 MOVD (13*4+8*8)(R13), F15
51
52 skipfprest:
53 MOVW.P 4(R13), R14
54 MOVM.IAW (R13), [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12]
55 ADD $(8*9), R13
56 MOVW R14, R15
57
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