// Copyright 2020 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_riscv64.h"

// 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
/*
 * Push arguments for fn (X10, X11, X13), along with all callee-save
 * registers. Note that at procedure entry the first argument is at
 * 8(X2).
 */
	ADD $(-8*29), X2
	MOV X10, (8*1)(X2) // fn unsafe.Pointer
	MOV X11, (8*2)(X2) // a unsafe.Pointer
	MOV X13, (8*3)(X2) // ctxt uintptr

	SAVE_GPR((8*4))
	MOV X1, (8*16)(X2)
	SAVE_FPR((8*17))

	// Initialize Go ABI environment
	CALL runtime·cgocallback(SB)

	RESTORE_GPR((8*4))
	MOV (8*16)(X2), X1
	RESTORE_FPR((8*17))

	ADD $(8*29), X2

	RET