![]() ![]() But note also that high_resolution_clock is not necessarily always increasing value, i.e. Re the posted code, u/jedwardsol has already remarked on the problematic use of printf. I've already answered the main question, about resolution of timers in MinGW g++ 9.2 and earlier. with conditional code for respectively Linux/Mac and Windows, or build time selection of implementation file. But I guess you will want to use the first approach, e.g. The second approach is not so risky as it may sound, and supports a header only semi-portable timer module. provide your own declarations of the API functions.either have the timer implementation separately compiled, limiting the use of to that file, or.So, for use of the Windows API in portable code (this doesn't have anything to do with MinGW g++ specifically) you will want to Thus you want to avoid that pollution for your general code. Re worries, the main Windows API header,, provides thousands upon thousands of havoc-wreaking macros, like, by default, defining min and max as macros. is due to relying on an old version of Microsoft's runtime at bottom. ![]() ![]() I believe the low resolution of MinGW g++ 9.2. But it shows that the needlessly low quality has some very undesirable consequences. It can be done by taking charge of memory allocation. Interestingly this low quality of the MinGW (compared to Visual C++) means that the most straightforward way of doing that example's measuring in a reliable portable way, with roughly three significant digits, consumes so much memory that for a 32-bit Windows executable it's very near the limit of not being doable. Here's the most relevant result, where sorting of sorted data is too fast to be measured directly with MinGW g++'s : Iterative "natural runs" merge-sort results in seconds, for 58112 words: Since the tutorial is a work in progress the link may change in the immediate future. A digression on measuring how long a code execution takes.“. Visual C++ 2019 has much better resolution, apparently down to microseconds (near the platform's timing limit).įor some typical results on an old laptop, see the end of the section on natural run merge sorting in my still-under-construction biggish linked list tutorial, which motivates and immediately precedes the section “4.6. Sometimes, in some runs, the resolution is 1 msec. if your post does not appear in the new queue, just send a message to the moderators.Ħ4-bit MinGW g++ 9.2 evidently has a worst resolution of 1/64ᵗʰ second, or 0.015625 seconds.make your questions relevant to other readers.give your post a meaningful title, i.e., NOT "I have a C++ problem" but, e.g., "Problem with nested for loops".thoroughly research for an answer first.Tips for improving your chances of getting helpful answers: Read these guidelines for how to ask smart questions.įor learning books, check The Definitive C++ Book Guide and Listįlair your post as SOLVED if you got the help you were looking for! If you need help with flairs, check out ITEM 1 in our guidelines page. Hasty-sounding questions get hasty answers, or none at all. New to C++? Learn at READ BEFORE POSTINGīefore you post, please read our sticky on proper code formatting. For general discussion and news about c++ see r/cpp. This is a subreddit for c++ questions with answers. ![]()
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