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.
7 // Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
8 // It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
9 TEXT ·set_crosscall2(SB),NOSPLIT,$0-0
10 MOVW _crosscall2_ptr(SB), R1
11 MOVW $crosscall2(SB), R2
15 // Called by C code generated by cmd/cgo.
16 // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
17 // Saves C callee-saved registers and calls cgocallback with three arguments.
18 // fn is the PC of a func(a unsafe.Pointer) function.
19 TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
20 SUB $(8*9), R13 // Reserve space for the floating point registers.
21 // The C arguments arrive in R0, R1, R2, and R3. We want to
22 // pass R0, R1, and R3 to Go, so we push those on the stack.
23 // Also, save C callee-save registers R4-R12.
24 MOVM.WP [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12], (R13)
25 // Finally, save the link register R14. This also puts the
26 // arguments we pushed for cgocallback where they need to be,
27 // starting at 4(R13).
30 // Skip floating point registers on GOARM < 6.
31 MOVB runtime·goarm(SB), R11
34 MOVD F8, (13*4+8*1)(R13)
35 MOVD F9, (13*4+8*2)(R13)
36 MOVD F10, (13*4+8*3)(R13)
37 MOVD F11, (13*4+8*4)(R13)
38 MOVD F12, (13*4+8*5)(R13)
39 MOVD F13, (13*4+8*6)(R13)
40 MOVD F14, (13*4+8*7)(R13)
41 MOVD F15, (13*4+8*8)(R13)
45 // We set up the arguments to cgocallback when saving registers above.
46 BL runtime·cgocallback(SB)
48 MOVB runtime·goarm(SB), R11
51 MOVD (13*4+8*1)(R13), F8
52 MOVD (13*4+8*2)(R13), F9
53 MOVD (13*4+8*3)(R13), F10
54 MOVD (13*4+8*4)(R13), F11
55 MOVD (13*4+8*5)(R13), F12
56 MOVD (13*4+8*6)(R13), F13
57 MOVD (13*4+8*7)(R13), F14
58 MOVD (13*4+8*8)(R13), F15
62 MOVM.IAW (R13), [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12]