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// 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 ·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·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·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
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