asm_amd64.s raw

   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  // Called by C code generated by cmd/cgo.
   9  // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
  10  // Saves C callee-saved registers and calls cgocallback with three arguments.
  11  // fn is the PC of a func(a unsafe.Pointer) function.
  12  // This signature is known to SWIG, so we can't change it.
  13  TEXT crosscall2(SB), NOSPLIT, $0-0
  14  	PUSH_REGS_HOST_TO_ABI0()
  15  
  16  	// Make room for arguments to cgocallback.
  17  	ADJSP $0x18
  18  
  19  #ifndef GOOS_windows
  20  	MOVQ DI, 0x0(SP) // fn
  21  	MOVQ SI, 0x8(SP) // arg
  22  
  23  	// Skip n in DX.
  24  	MOVQ CX, 0x10(SP) // ctxt
  25  
  26  #else
  27  	MOVQ CX, 0x0(SP) // fn
  28  	MOVQ DX, 0x8(SP) // arg
  29  
  30  	// Skip n in R8.
  31  	MOVQ R9, 0x10(SP) // ctxt
  32  
  33  #endif
  34  
  35  	CALL runtime·cgocallback(SB)
  36  
  37  	ADJSP $-0x18
  38  	POP_REGS_HOST_TO_ABI0()
  39  	RET
  40