C Language
C is a general-purpose computer programming language used for operating systems, libraries, games and other high performance work. This tag should be used with general questions concerning the C language, as defined in the ISO 9899:2011 standard. If applicable, include a version-specific tag such as c99 or c90 for questions relating to older language standards. C is distinct from C++ and it should not be combined with the C++ tag absent a rational reason.
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How can one see content of stack with GDB?
I am new to GDB, so I have some questions: How can I look at content of the stack? Example: to see content of
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Quickly find whether a value is present in a C array?
I have an embedded application with a time-critical ISR that needs to iterate through an array of size 256 (pr
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Possible GCC bug when returning struct from a function
I believe I found a bug in GCC while implementing O'Neill's PCG PRNG. (Initial code on Godbolt'
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Can num++ be atomic for 'int num'?
In general, for int num, num++ (or ++num), as a read-modify-write operation, is not atomic. But I often see co
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Why does GCC generate such radically different assembly for nearly the same C code?
While writing an optimized ftol function I found some very odd behaviour in GCC 4.6.1. Let me show you the cod
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Is inline assembly language slower than native C++ code?
I tried to compare the performance of inline assembly language and C++ code, so I wrote a function that add tw
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Protecting executable from reverse engineering?
I've been contemplating how to protect my C/C++ code from disassembly and reverse engineering. Normally
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Why does GCC use multiplication by a strange number in implementing integer division?
I've been reading about div and mul assembly operations, and I decided to see them in action by writing a
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What is exactly the base pointer and stack pointer? To what do they point?
Using this example coming from wikipedia, in which DrawSquare() calls DrawLine(), (Note that this diagram h
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Is 'switch' faster than 'if'?
Is a switch statement actually faster than an if statement? I ran the code below on Visual Studio 2010's
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Using GCC to produce readable assembly?
I was wondering how to use GCC on my C source file to dump a mnemonic version of the machine code so I could s
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How do you get assembler output from C/C++ source in gcc?
How does one do this? If I want to analyze how something is getting compiled, how would I get the emitted ass
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What is the behavior of integer division?
For example, int result; result = 125/100; or result = 43/100; Will result always be the floor of the
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How does C compute sin() and other math functions?
I've been poring through .NET disassemblies and the GCC source code, but can't seem to find anywhere
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The most efficient way to implement an integer based power function pow(int, int)
What is the most efficient way given to raise an integer to the power of another integer in C? // 2^3 pow(2,3
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Fast ceiling of an integer division in C / C++
Given integer values x and y, C and C++ both return as the quotient q = x/y the floor of the floating point eq
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Fastest way to determine if an integer is between two integers (inclusive) with known sets of values
Is there a faster way than x >= start && x <= end in C or C++ to test if an integer is between t
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Is there a standard sign function (signum, sgn) in C/C++?
I want a function that returns -1 for negative numbers and +1 for positive numbers. http://en.wikipedia.org/wi
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Divide a number by 3 without using *, /, +, -, % operators
How would you divide a number by 3 without using *, /, +, -, %, operators? The number may be signed or unsig
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Why does the C preprocessor interpret the word "linux" as the constant "1"?
Why does the C preprocessor in GCC interpret the word linux (small letters) as the constant 1? test.c: #incl
