align8.h

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/*
    Harmonic sinusoidal modelling and tools

    C++ code package for harmonic sinusoidal modelling and relevant signal processing.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2011 Wen Xue.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.
*/
//---------------------------------------------------------------------------

#ifndef align8H
#define align8H

//--stack alignment----------------------------------------------------------
/*
  These two macros are used to envelop a function call so that the function is called with a stack
  pointer that is a multiple of 8. Aligning the stack does not automatically ensure that local double
  -precision floating-point variables (or other variables one wants to align to 8-byte boundaries) are
  aligned to 8-byte boundaries; one has to adjust the variable declaration order, using dummy variables
  if necessary, to make the alignment happen.
*/
//macro ALIGN_STACK_8 moves the current stack pointer to a multiple of 8
#define ALIGN_STACK_8 {int alignstack; asm {mov alignstack, esp} asm {and esp, 0xFFFFFFF8}
//macro RESTORE_STACK moves the stack pointer back to where it was before ALIGN_STACK_8
#define RESTORE_STACK asm {mov esp, alignstack}}

//ALIGN8 ensures F is executed with a start stack pointer divisible by 8. Currently disabled.
#define ALIGN8(F) F
//uncomment the following line to enable stack alignment
//#define ALIGN8(F) ALIGN_STACK_8 F RESTORE_STACK

//--64-bit aligned memory allocation routines--------------------------------
void* malloc8(unsigned size);
void free8(void* buffer8);

#endif