POV-Ray : Newsgroups : povray.macintosh : Some simple testing needed : Re: Some simple testing needed Server Time
25 Jan 2022 03:50:55 EST (-0500)
  Re: Some simple testing needed  
From: clipka
Date: 15 Feb 2019 11:42:12
Message: <5c66ebe4@news.povray.org>
Am 15.02.2019 um 08:40 schrieb ingo:
> compiling with the wrong compiler and wrong option creates no errors and
> a program that won't run but you don't notice because the test file test
> is not called but test (check file types and compare values) that is
> already present on the system...

Oh yeah - that's a good one :)

Even better than trying to judge the run-time performance of certain 
code under optimization, and typing `g++ -o3 -ffast-math -o test 
test.cpp` instead of `g++ -O3 -ffast-math -o test test.cpp`...

> But, the proper results are in:
> 
> FreeBSD Clang 6.0
> Delay 1
> 0.000u 0.005s 0:01.07 0.0%      0+0k 2+0io 0pf+0w
> 
> Delay 10
> 0.000u 0.006s 0:10.64 0.0%      0+0k 6+0io 15pf+0w
> 
> Delay 100
> 0.000u 0.005s 1:46.24 0.0%      0+0k 2+0io 0pf+0w

That's 1.07 ms, 10.64 ms and 106.24 ms, respectively, which makes a lot 
more sense :)

> Mingwin g++.exe (Rev1, Built by MSYS2 project) 8.2.1 20181207
> Delay 1
> real    0m15.822s
> user    0m0.000s
> sys     0m0.015s
> 
> Delay 10
> real    0m15.759s
> user    0m0.000s
> sys     0m0.031s
> 
> Delay 100
> real    1m49.566s
> user    0m0.015s
> sys     0m0.031s
> 
> ingo

That, too, makes sense, and indicates that MinGW has a minimum wait of 
ca. 15 ms (on average at any rate). Which is fine, as C++11 allows 
implementations to wait longer than requested (but not less).


Post a reply to this message

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.