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// Copyright 2015 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"
#include "abi_arm64.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 ·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
/*
* We still need to save all callee save register as before, and then
* push 3 args for fn (R0, R1, R3), skipping R2.
* Also note that at procedure entry in gc world, 8(RSP) will be the
* first arg.
*/
SUB $(8*24), RSP
STP (R0, R1), (8*1)(RSP)
MOVD R3, (8*3)(RSP)
SAVE_R19_TO_R28(8*4)
SAVE_F8_TO_F15(8*14)
STP (R29, R30), (8*22)(RSP)
// Initialize Go ABI environment
BL runtime·load_g(SB)
BL runtime·cgocallback(SB)
RESTORE_R19_TO_R28(8*4)
RESTORE_F8_TO_F15(8*14)
LDP (8*22)(RSP), (R29, R30)
ADD $(8*24), RSP
RET
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