Questions tagged [gcc]
For code written to be compiled specifically by the GCC, which stands for the GNU Compiler Collection. Developers often compile several languages using this compiler collection.
22
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32x32x32 units octree, that supports 15-bit data units
The idea is to have an octree that stores a 32x32x32 region of 15 bit values more efficiently than a 32x32x32 array, because if all 8 leaf nodes of a given branch are the same, the branch does not ...
- 825
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2
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128-bit integer type in GCC/Clang
When working on my projects, I often need a 128-bit integer type. For this purpose, I use the __int128 compiler extension. Here is the implementation I am currently ...
- 299
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3
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826
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Efficiently read a file into a (C) string using POSIX APIs
Exactly what the title says, this is a C++ class that attempts to read a file into a null-terminated string as efficiently as possible, using POSIX APIs. Obviously this is not intended to be portable ...
- 258
2
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2
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Reference-counted smart pointer in C
About
I've been experimenting with gcc's __cleanup__ attribute, and thought it'd be a great fit for a memory-safe smart pointer for C.
This is the implementation. ...
6
votes
3
answers
521
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4 different implementations of modulo with fully defined behavior
I've implemented the 3 variants of the modulo operation described on this Wikipedia page.
The goal is to have fully defined behavior for all inputs.
Code
Implementation with truncated division (result ...
- 163
6
votes
2
answers
983
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Bash script - compile and run c++ code for coding competitions
This is a simple bash script that I use to compile and run single C++ files for coding competitions.
Features:
Detects if there is a corresponding .in file next to ...
- 165
-7
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1
answer
125
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Can you please give feedback on my C++ Code? [closed]
Can you please give feedback on my C++ code so I can get better at writing code? I want a code that is well written.
This Code uses the cstdio include for good performance and cstdint include because ...
10
votes
3
answers
5k
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C++ Template to implement the Factory Pattern
Design
A template class that will create a concrete instance of an interface class when given the name (as a string) of the concrete class.
This design is often seen in code, so the purpose of this ...
- 373
4
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1
answer
1k
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Macro for counting number of elements in an array
We all know the classic version of counting the number of elements in a C array: sizeof(a)/sizeof(*a)
But this is dangerous, because if used on a pointer it will ...
- 903
0
votes
3
answers
118
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Safer & simpler allocation functions and macros
I wrote a bunch of functions and macros for safer and simpler allocation. They are documented in their files.
Disclaimer:
The library requires POSIX extensions, GCC extensions, and LIBBSD ...
3
votes
1
answer
124
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Clang preprocessor concatenates an extra space vs. gcc - standard C99
I maintain a C library project both on gcc and clang.
I am looking for advice on how to make the following macros more portable, terse, readable or standard abiding.
When I compile
...
- 211
3
votes
2
answers
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A little C++ program to have timed rounds for a game
I know it could be better, but I’m new to C++, so I don’t know many of the tricks, along with some of the includes that are already obsolete.
This program asks for names as input, adds a time for ...
- 31
4
votes
3
answers
305
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Encapsulating snprintf to simplify usage: sbprintf & swnprintf
After writing swnprintfand sbprintf in C (Encapsulating snprintf to avoid repetition of sizeof), I've written a C++ version of ...
5
votes
3
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881
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Encapsulating snprintf to avoid repetition of sizeof
Correct usage of snprintf involves very long and repetitive lines:
...
12
votes
3
answers
1k
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Register "%b" conversion specifier
I'm writing a library to register the b, B conversion specifiers and make them work the closest possible to ...
3
votes
0
answers
592
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Generic Makefile for C projects
I'm trying to create a generic Makefile that will work with the following directory structure:
Project Directory
Makefile
main.c source file
source directory
Source files
include directory
Header ...
- 349
0
votes
1
answer
107
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gcc constant time implemenation [closed]
I need to make the following function time constant - I have already removed if statements and have written it down to one line in the loop.
...
- 103
2
votes
1
answer
431
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Printing 64-bit decimal numbers in freestanding environment
I need to print signed 64-bit numbers in decimal form. Program runs in freestanding environment (no C library available, libgcc may be unavailable too, or may not work correctly). So I can't use ...
- 159
2
votes
0
answers
74
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String to long double conversion using FBLD
I always wanted to try fbld x87 instruction to aid to convert string to floating point value.
I sure a chance to face this instruction in disassembly of all the ...
- 624
3
votes
2
answers
945
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Makefile for a small JNI project
So I'm going to publish this small project on GitHub and I thought I'd better do a makefile for it. The source code consists of
1 Java Class
1 Native JNI module written in C
1 stdlib wrapper object ...
- 193
11
votes
1
answer
1k
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Computing average without overflows and with half-decent precision
At some point I needed to compute the average of a big collection of integers. I knew the size of the collection prior computation, but a naive average computation was prone to integer overflow while ...
- 19.9k
10
votes
1
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620
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Vectorizing the product of an array of complex numbers
I am trying to write fast/optimal code to vectorize the product of an array of complex numbers. In simple C this would be:
...
- 191