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 14 // The C arguments arrive in R0, R1, R2, and R3. We want to
15 // pass R0, R1, and R3 to Go, so we push those on the stack.
16 // Also, save C callee-save registers R4-R12.
17 MOVM.WP [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12], (R13)
18 19 // Finally, save the link register R14. This also puts the
20 // arguments we pushed for cgocallback where they need to be,
21 // starting at 4(R13).
22 MOVW.W R14, -4(R13)
23 24 // Save VFP callee-saved registers D8-D15 (same as S16-S31).
25 // Note: We always save these since we target hard-float ABI.
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 BL runtime·load_g(SB)
36 37 // We set up the arguments to cgocallback when saving registers above.
38 BL runtime·cgocallback(SB)
39 40 MOVD (13*4+8*1)(R13), F8
41 MOVD (13*4+8*2)(R13), F9
42 MOVD (13*4+8*3)(R13), F10
43 MOVD (13*4+8*4)(R13), F11
44 MOVD (13*4+8*5)(R13), F12
45 MOVD (13*4+8*6)(R13), F13
46 MOVD (13*4+8*7)(R13), F14
47 MOVD (13*4+8*8)(R13), F15
48 49 MOVW.P 4(R13), R14
50 MOVM.IAW (R13), [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12]
51 ADD $(8*9), R13
52 MOVW R14, R15
53