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// Copyright 2022 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_loong64.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
MOVV _crosscall2_ptr(SB), R5
MOVV $crosscall2_trampoline<>(SB), R6
MOVV R6, (R5)
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 (R4, R5, R7), skipping R6.
* Also note that at procedure entry in gc world, 8(R29) will be the
* first arg.
*/
ADDV $(-23*8), R3
MOVV R4, (1*8)(R3) // fn unsafe.Pointer
MOVV R5, (2*8)(R3) // a unsafe.Pointer
MOVV R7, (3*8)(R3) // ctxt uintptr
SAVE_R22_TO_R31((4*8))
SAVE_F24_TO_F31((14*8))
MOVV R1, (22*8)(R3)
// Initialize Go ABI environment
JAL runtime·load_g(SB)
JAL runtime·cgocallback(SB)
RESTORE_R22_TO_R31((4*8))
RESTORE_F24_TO_F31((14*8))
MOVV (22*8)(R3), R1
ADDV $(23*8), R3
RET
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