请教张教主程序优化问题

只看该作者 · 2009-9-5 12:47

芯片：MC68HC908LK24
环境：freescale codewarrior 6.2
问题：部分程序被编译器干掉，甚至一些对寄存器赋值语句
   NumberByte = 0;
      SPDR = 0xd;
      断点没有办法设置到这两个语句，两条语句也没有被执行，编译时没有任何提示信息。
源代码：
#include <MC68HC908LK24.h>          /* I/O map for MC68HC908LK24CFQ */
#include "MCUinit.h"
#include "main.h"

#ifdef __cplusplus
extern "C"
#endif

extern unsigned char StateSPIDEV;
extern unsigned char StateSPIen;
extern unsigned char StateSPICounter;
extern unsigned char NumberByte;

void SPIProcess(void)
{
  if(StateSPIDEV == 1)
  {
StateSPIDEV = 2;
CS_ADE = 0;
StateSPICounter = 0;
StateSPIen = 1;

NumberByte = 0;
SPDR = 0xd;
  }
  else if(StateSPIDEV == 4)
  {
CS_ADE = 0;
StateSPIDEV = 5;
NumberByte = 0;
SPDR = 0xd;
  }
  else if(StateSPIDEV == 7)
  {
CS_ADE = 0;
StateSPIDEV = 8;
NumberByte = 0;
SPDR = 0xd;
  }
  else if(StateSPIDEV == 10)
  {
CS_ADE = 0;
StateSPIDEV = 11;
NumberByte = 0;
SPDR = 0xd;
  }
  else if(StateSPIDEV == 13)
  {
CS_ADE = 0;
StateSPIDEV = 14;
NumberByte = 0;
SPDR = 0xd;
  }
  else if(StateSPIDEV == 15)
  {
CS_ADE = 0;
StateSPIen = 0;
StateSPICounter = 0;
  }
}

void VoltageInterruptProcess(void)
{
  unsigned char tmpt;

  NumberByte++;
  if(NumberByte == 1) SPDR = 0x55;
  else if(NumberByte == 2) SPDR = 0x55;
  else if(NumberByte == 3) SPDR = 0x55;

  else if(NumberByte == 4)
  {
CS_ADE = 1;
// tmpt = 2;
tmpt = 4;
CS_ADE = 1;
// tmpt = 2;
tmpt = 4;
SPDR = 0xe;
  }
  else if(NumberByte == 5) SPDR = 0x55;
  else if(NumberByte == 6) SPDR = 0x55;
  else if(NumberByte == 7) SPDR = 0x55;

  else if(NumberByte == 8)
  {
CS_ADE = 1;
// tmpt = 2;
tmpt = 4;
CS_ADE = 1;
// tmpt = 2;
tmpt = 4;
SPDR = 0xe;
  }
  else if(NumberByte == 9) SPDR = 0x55;
  else if(NumberByte == 10) SPDR = 0x55;
  else if(NumberByte == 11) SPDR = 0x55;
  else if(NumberByte == 8)
  {
CS_ADE = 1;
NumberByte = 0;
StateSPIDEV++;
  }

}

只看该作者 · 2009-9-5 22:06

没事的啦。
你重复了这两条指令好几遍，编译器帮你生成一个函数然后重复调用以便节约代码空间。看汇编代码执行过程就明白了。

请教张教主程序优化问题

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