[ros-dev] Re:[ros-svn] [gdalsnes] 18113:-reorderInsertXscendingOrdermacro argument order and update uses

[Jakob Eriksson]

Take a look at the code below. More readable by far IMHO.



Casper Hornstrup wrote:

>  
>
>>-----Original Message-----
>>From: ros-dev-bounces at reactos.com [mailto:ros-dev-bounces at reactos.com] On Behalf Of Thomas
>>Weidenmueller
>>Sent: 28. september 2005 17:27
>>To: ReactOS Development List
>>Subject: Re: [ros-dev] Re:[ros-svn] [gdalsnes] 18113:-reorderInsertXscendingOrdermacro argument
>>order and update uses
>>
>>Casper Hornstrup wrote:
>>    
>>
>>>      
>>>
>>>>The alternative is: do the cleanup at every return, use goto or use
>>>>try/finally.
>>>>1)Cleanup at every return is madness. Most functions in ros do a large
>>>>amount of cleanup at each return and I sometimes spot mistakes where
>>>>one/more return misses some cleanup. Those errors are _hard_ to find.
>>>>        
>>>>
>>>The functions are too large then. Use more smaller functions instead.
>>>      
>>>
>>I agree with Nathan. Having tons of small functions often isn't a good
>>solution, especially when you'd have to create dozens of small helper
>>functions. That not just only generates slower code but also makes it
>>more difficult to get a picture of the algorithm used. I much more
>>prefer jumping to cleanup labels the way Nathan demonstrated it. Of
>>course I avoid it where it doesn't make sense.
>>
>>- Thomas
>>    
>>
>
>There is practically no difference in execution speed.
>
>Casper
>
>  
>
>------------------------------------------------------------------------
>
>#include <stdio.h>
>#include <windows.h>
>
>#define NumberOfIterations	60000
>
>void RunCollapsed()
>{
>	int i, j;
>	for (i = 0; i < NumberOfIterations; i++)
>	{
>		for (j = 0; j < NumberOfIterations; j++)
>		{
>		}
>	}
>}
>
>static void Helper()
>{
>	int j;
>	for (j = 0; j < NumberOfIterations; j++)
>	{
>	}
>}
>
>void RunNonCollapsed()
>{
>	int i;
>	for (i = 0; i < NumberOfIterations; i++)
>	{
>		Helper();
>	}
>}
>
>void RunOnce(LARGE_INTEGER *collapsedTicks, LARGE_INTEGER *nonCollapsedTicks)
>{
>	LARGE_INTEGER start;
>	LARGE_INTEGER stop;
>	
>	QueryPerformanceCounter(&start);
>	RunCollapsed();
>	QueryPerformanceCounter(&stop);
>	collapsedTicks->QuadPart = stop.QuadPart - start.QuadPart;
>	printf("Collapsed: %lu ticks\n", collapsedTicks->QuadPart);
>
>	QueryPerformanceCounter(&start);
>	RunNonCollapsed();
>	QueryPerformanceCounter(&stop);
>	nonCollapsedTicks->QuadPart = stop.QuadPart - start.QuadPart;
>	printf("NonCollapsed: %lu ticks\n", nonCollapsedTicks->QuadPart);
>
>	printf("%d%%\n", (nonCollapsedTicks->QuadPart * 100) / collapsedTicks->QuadPart);
>}
>
>int main()
>{
>	LARGE_INTEGER collapsedTicks;
>	LARGE_INTEGER nonCollapsedTicks;
>	LARGE_INTEGER totalCollapsedTicks;
>	LARGE_INTEGER totalNonCollapsedTicks;
>	int i;
>
>	totalCollapsedTicks.QuadPart = 0;
>	totalNonCollapsedTicks.QuadPart = 0;
>	for (i = 0; i < 10; i++)
>	{
>		RunOnce(&collapsedTicks, &nonCollapsedTicks);
>		totalCollapsedTicks.QuadPart += collapsedTicks.QuadPart;
>		totalNonCollapsedTicks.QuadPart += nonCollapsedTicks.QuadPart;
>	}
>	printf("Average: %d%%\n", (totalNonCollapsedTicks.QuadPart * 100) / totalCollapsedTicks.QuadPart);
>}
>  
>
>------------------------------------------------------------------------
>
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