Re: [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(a)reactos.com [mailto:[e-mail]] 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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