| // Copyright 2016 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" | |
| // Set the x_crosscall2_ptr C function pointer variable point to crosscall2. | |
| // It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2 | |
| // Use a local trampoline, to avoid taking the address of a dynamically exported | |
| // function. | |
| TEXT 路set_crosscall2(SB),NOSPLIT,$0-0 | |
| MOVD _crosscall2_ptr(SB), R1 | |
| MOVD $crosscall2_trampoline<>(SB), R2 | |
| MOVD R2, (R1) | |
| RET | |
| TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0 | |
| JMP crosscall2(SB) | |
| // Called by C code generated by cmd/cgo. | |
| // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr) | |
| // Saves C callee-saved registers and calls cgocallback with three arguments. | |
| // fn is the PC of a func(a unsafe.Pointer) function. | |
| TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0 | |
| // Start with standard C stack frame layout and linkage. | |
| // Save R6-R15 in the register save area of the calling function. | |
| STMG R6, R15, 48(R15) | |
| // Allocate 96 bytes on the stack. | |
| MOVD $-96(R15), R15 | |
| // Save F8-F15 in our stack frame. | |
| FMOVD F8, 32(R15) | |
| FMOVD F9, 40(R15) | |
| FMOVD F10, 48(R15) | |
| FMOVD F11, 56(R15) | |
| FMOVD F12, 64(R15) | |
| FMOVD F13, 72(R15) | |
| FMOVD F14, 80(R15) | |
| FMOVD F15, 88(R15) | |
| // Initialize Go ABI environment. | |
| BL runtime路load_g(SB) | |
| MOVD R2, 8(R15) // fn unsafe.Pointer | |
| MOVD R3, 16(R15) // a unsafe.Pointer | |
| // Skip R4 = n uint32 | |
| MOVD R5, 24(R15) // ctxt uintptr | |
| BL runtime路cgocallback(SB) | |
| FMOVD 32(R15), F8 | |
| FMOVD 40(R15), F9 | |
| FMOVD 48(R15), F10 | |
| FMOVD 56(R15), F11 | |
| FMOVD 64(R15), F12 | |
| FMOVD 72(R15), F13 | |
| FMOVD 80(R15), F14 | |
| FMOVD 88(R15), F15 | |
| // De-allocate stack frame. | |
| MOVD $96(R15), R15 | |
| // Restore R6-R15. | |
| LMG 48(R15), R6, R15 | |
| RET | |