fastmath.h

u盘MCU端源代码,开发U盘的可以参考.

/*============================================================================
  ____________________________________________________________________________
                                ______________________________________________
   SSSS  M   M          CCCC          Standard Microsystems Corporation
  S      MM MM   SSSS  C                    Austin Design Center
   SSS   M M M  S      C                 11000 N. Mopac Expressway
      S  M   M   SSS   C                Stonelake Bldg. 6, Suite 500
  SSSS   M   M      S   CCCC                Austin, Texas 78759
                SSSS            ______________________________________________
  ____________________________________________________________________________
  Copyright(C) 1999, Standard Microsystems Corporation
  All Rights Reserved.
  This program code listing is proprietary to SMSC and may not be copied,
  distributed, or used without a license to do so.  Such license may have
  Limited or Restricted Rights. Please refer to the license for further
  clarification.
  ____________________________________________________________________________
  Notice: The program contained in this listing is a proprietary trade
  secret of SMSC, Hauppauge, New York, and is copyrighted
  under the United States Copyright Act of 1976 as an unpublished work,
  pursuant to Section 104 and Section 408 of Title XVII of the United
  States code. Unauthorized copying, adaption, distribution, use, or
  display is prohibited by this law.
  ____________________________________________________________________________
  Use, duplication, or disclosure by the Government is subject to
  restrictions as set forth in subparagraph(c)(1)(ii) of the Rights
  in Technical Data and Computer Software clause at DFARS 52.227-7013.
  Contractor/Manufacturer is Standard Microsystems Corporation,
  80 Arkay Drive, Hauppauge, New York, 1178-8847.
  ____________________________________________________________________________
  ____________________________________________________________________________
  fastmath.h - macros to do quick arithmetic w/o calling a slow library
  ____________________________________________________________________________
  comments tbd
  ____________________________________________________________________________
  Revision History
  Date      Who  Comment
  ________  ___  _____________________________________________________________
  10/15/01  cds  initial version
  01/15/02  cds  updated 16-bit fast-math functions to work with t_uw16 struct
  11/05/02  cds  added bit_count8/16 functions
============================================================================*/

//------------------------------------------------------------------------------
// helpful macros for converting cdbs to 16 & 32 bit values
#define _uint16(h,l)          ((uint16)((((uint16)(h))<<8)|(((uint16)(l)))))
#define _uint32(hh,hl,lh,ll)  ((((uint32)(_uint16(hh,hl)))<<16)|((uint32)(_uint16(lh,ll))))
#define _hw(dw)               ((uint16)((uint32)dw>>(uint32)16))
#define _lw(dw)               ((uint16)((uint32)dw&0x0000ffff))

//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
#define _u32_equ_0(val32)  (0==(val32.u8.hi|val32.u8.lh|val32.u8.hl|val32.u8.lo))

//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
#define _u32_equ(lhs, rhs) (0==((lhs.u8.hi^rhs.u8.hi)|(lhs.u8.lh^rhs.u8.lh)|(lhs.u8.hl^rhs.u8.hl)|(lhs.u8.lo^rhs.u8.lo)))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u32_lt(lhs, rhs)  ((lhs.u32)<(rhs.u32))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u32_gt(lhs, rhs)  ((lhs.u32)>(rhs.u32))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u32_dec(val32)    ((val32.u32--))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u32_inc(val32)    ((val32.u32++))

//------------------------------------------------------------------------------
// 16-bit compare against 0
// inclusive-or the 8-bit components
//------------------------------------------------------------------------------
#define _u16_equ_0(val16)  (0==(val16.u8.lo|val16.u8.hi))

//------------------------------------------------------------------------------
// compare 2 16bit values for equality
// exclusive-or the 8-bit components, check for 0.
//------------------------------------------------------------------------------
#define _u16_equ(lhs, rhs) (0==((lhs.u8.lo^rhs.u8.lo)|(lhs.u8.hi^rhs.u8.hi)))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u16_lt(lhs, rhs)  ((lhs.u16)<(rhs.u16))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u16_gt(lhs, rhs)  ((lhs.u16)>(rhs.u16))

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u16_dec(val16)    ((val16.u8.hi-=(val16.u8.lo--?0:1))) 

//------------------------------------------------------------------------------
// still slow
//------------------------------------------------------------------------------
#define _u16_inc(val16)    ((val16.u8.hi+=(++val16.u8.lo?0:1)))

//+-----------------------------------------------------------------------------
// Name:
//   bit_count8()
//
// Declaration:
//   t_result bit_count8(void) reentrant ;
//
// Purpose:
//   Count # of bits in a 8-bit value
//
// Arguments:
//   val  - 8-bit value in which to count bits
//
// Return:
//   0-8, depending on the number of bits set in 'val'
// Notes:
//
// Since:
//   fmc-1.0
//------------------------------------------------------------------------------
uint8 bit_count8(uint8 val) reentrant;

//+-----------------------------------------------------------------------------
// Name:
//   TBD
//
// Declaration:
//   TBD
//
// Purpose:
//   Count # of bits in a 16-bit value
//
// Arguments:
//   val  - 16-bit value in which to count bits
//
// Return:
//   0-16, depending on the number of bits set in 'val'
// Notes:
//
// Since:
//   fmc-1.0
//------------------------------------------------------------------------------
uint8 bit_count16(uint16 val) reentrant;

//---eof------------------------------------------------------------------------