[llvm-commits] [cfe-commits] [PATCH][Review Request] EarlyCSE stack overflow - bugzilla 11794

[Jakob Stoklund Olesen]

On Jan 20, 2012, at 11:21 AM, Andrew Trick wrote:

> On Jan 19, 2012, at 3:41 PM, Jakob Stoklund Olesen wrote:
> 
>> On Jan 19, 2012, at 1:41 PM, Lenny Maiorani wrote:
>>> List: 92.473490 seconds
>>> Stack: 15.575143 seconds
>>> Deque: 9.129154 seconds
>>> Deque iter insert: 7.384741 seconds
>>> Vector: 13.387473 seconds
> 
> My stack (doing the same thing as deque iter insert):
> accum = -12238
> time = 63.691762 seconds
> 
> 
> Deque iter insert:
> accum = -12238
> time = 67.037268 seconds
> 
> 
> Deque:
> accum = -12238
> time = 84.097848 seconds
> <stack-test.cpp>
> 
> Yay for simplicity and common sense. I don't think you need a benchmark to prove that one data structure access is faster than two of the same type of access.
> 
>> Thanks for taking the time to do this and actually posting numbers.
> 
> Thanks Lenny. I'd like to see more measurements in general. I just want to give Jakob a hard time for his faith in numbers.

You are both wrong, of course. Everybody knows that a vector is the best solution for this problem. ;-)

However, this is not about having faith in numbers. It's about thinking to produce them in the first place. This sentiment is far too rare: "Before I blindly stated that I thought std::stack or std::deque would be better, I decided I would verify this."

I though Lenny's numbers were odd, but I wanted him to fix the correctness problem first.

/jakob