Alphaneo Alphaneo Add a comment. Active Oldest Votes. Improve this answer. MarkusQ MarkusQ One exception being standards compliant compilers for 8-bit microcontrollers. In that case an unsigned char is more efficient since bits is the minimum int size. But does anyone really do much c on an 8-bit bus anymore? By that point I'd expect you'd be doing custom asm or something, and even so I'm not sure why.
MarkusQ, there are a lot more things still running 8-bit buses than you'd guess. The architecture looks like it will never die, for example, and the Z80 lives on too RBerteig -- I have a warm spot in my heart for the Z80 and a depressingly large fraction of my brain that says "call! But my point was, who programs a Z80 in C? That seems almost criminal — MarkusQ. Just look at the number of assembly instructions that your code translates to, and also the clock cycles of each of them.
In this case, measuring will become a bit difficult, I guess. Not sure I understood what your getting at. Let me clarify: I meant when wondering on performances at such a low level ie not algorithm , comparing is better. Create a benchmark program with intensive use of bools and measure with char or bool and comapre to 64 bits bools.
You get into all sorts of fun things like memory alignment, how much data is fetched at a time, etc But testing to verify is always a good thing. Judge Maygarden Judge Maygarden TofuBeer TofuBeer I would recommend to use preprocessor. TrayMan TrayMan 6, 2 2 gold badges 21 21 silver badges 32 32 bronze badges. If you pack 1 , then obviously when loading, we the number of instruction to single out a bool is be more than just loading a native width words.
Can you visualize this sitation? X86 can load a byte directly to the low 8-bits of registers eq. TrayMan -- Count cycles and bytes for non-aligned data to see what he means. There can be a significant penalty, and as murphy says if there can be there will be. How can a byte be unaligned?
Even if the hardware has to read a full bit word to get the byte, it still doesn't need to do an unaligned read. Assaf Lavie Assaf Lavie Using a char might be slower than using an integer.
Arafangion Arafangion Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. Dede Pons Pundit. What are the three Boolean operators? Boolean operators form the basis of mathematicalsets and database logic. They connect your search words together toeither narrow or broaden your set of results. Xavier Landiola Pundit.
How do you define a string? A string is a sequence of characters stored in acharacter array. A string is a text enclosed in doublequotation marks. A character such as 'd' is not a string andit is indicated by single quotation marks. Luanne Cleinmann Pundit.
How many bits is a Boolean? Libe Moraitopoulos Pundit. What is Boolean logic? Boolean Logic , Illustrated. Dailyn Kerr Teacher. What is a Boolean search? Boolean search is a type of search allowing users to combine keywords with operators or modifiers such as AND, NOT and OR to further produce more relevant results.
This would limit the search results to only thosedocuments containing the two keywords. Weihao Burkarth Teacher. Is 0 true or false in C? A true boolean data type could be used forstoring logical values, and would only have two legal values -" true ", and " false ". C does not have booleandata types, and normally uses integers for boolean testing.
Zero isused to represent false , and One is used to represent true. Garuda Sarrudo Teacher. Is 0 True or false? Basicly there is no boolean value. The number 0 is considered to be false and all other numbers areconsidered to be true. Amaiur Cinzia Teacher. Is array a data type in C? C - Arrays. Arrays a kind of data structure that can store a fixed-size sequentialcollection of elements of the same type.
A specific elementin an array is accessed by an index. All arrays consist of contiguous memory locations. Cherry Korzendorfer Reviewer. Is 0 true or false in Java? A Boolean value is one with two choices: true orfalse , yes or no, 1 or 0. Furqan Surugiu Reviewer. What is enum in C? Enumeration or enum in C. Enumeration or enum is a user defined data type in C. It is mainlyused to assign names to integral constants, the names make aprogram easy to read and maintain.
Following is an example of enum declaration. Cita Nath Reviewer. What is string data type? A string is a data type used in programming, such as an integer and floating point unit,but is used to represent text rather than numbers.
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