github.com/ice-blockchain/go/src@v0.0.0-20240403114104-1564d284e521/runtime/cgo/asm_amd64.s (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "textflag.h"
     6  #include "abi_amd64.h"
     7  
     8  // Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
     9  // It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
    10  // Use a local trampoline, to avoid taking the address of a dynamically exported
    11  // function.
    12  TEXT ·set_crosscall2(SB),NOSPLIT,$0-0
    13  	MOVQ	_crosscall2_ptr(SB), AX
    14  	MOVQ	$crosscall2_trampoline<>(SB), BX
    15  	MOVQ	BX, (AX)
    16  	RET
    17  
    18  TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0
    19  	JMP	crosscall2(SB)
    20  
    21  // Called by C code generated by cmd/cgo.
    22  // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
    23  // Saves C callee-saved registers and calls cgocallback with three arguments.
    24  // fn is the PC of a func(a unsafe.Pointer) function.
    25  // This signature is known to SWIG, so we can't change it.
    26  TEXT crosscall2(SB),NOSPLIT,$0-0
    27  	PUSH_REGS_HOST_TO_ABI0()
    28  
    29  	// Make room for arguments to cgocallback.
    30  	ADJSP	$0x18
    31  #ifndef GOOS_windows
    32  	MOVQ	DI, 0x0(SP)	/* fn */
    33  	MOVQ	SI, 0x8(SP)	/* arg */
    34  	// Skip n in DX.
    35  	MOVQ	CX, 0x10(SP)	/* ctxt */
    36  #else
    37  	MOVQ	CX, 0x0(SP)	/* fn */
    38  	MOVQ	DX, 0x8(SP)	/* arg */
    39  	// Skip n in R8.
    40  	MOVQ	R9, 0x10(SP)	/* ctxt */
    41  #endif
    42  
    43  	CALL	runtime·cgocallback(SB)
    44  
    45  	ADJSP	$-0x18
    46  	POP_REGS_HOST_TO_ABI0()
    47  	RET