Clik here to view.
why this recursive programis having garbage value even after assignment [closed]
The values in image appear from nowhere:What are these values and if they are garbage values then why they are still present after assigning J the value. I am also attaching the source code.int...
View ArticleGCC -g vs -g3 GDB Flag: What is the Difference?
When compiling C source code with either gcc or Clang, I always use the -g flag to generate debugging information for gdb.gcc -g -o helloworld helloworld.cI noticed that some people recommend -g3...
View ArticleHow to define a string literal in gcc command line?
In gcc command line, I want to define a string such as -Dname=Mary, then in the source code I want printf("%s", name); to print Mary.How could I do it?
View ArticleInclude openssl/libcrypto statically
I am trying to compile an app with static curl and i it seems OpenSSL is not properly linked.COMPILE CMD:$(CXX) $(CXXFLAGS) program1.cpp /opt/curl-7.62.0/lib/libcurl.a...
View ArticleWhy in C does the function sizeof() output the size of right most operand...
I have the following code in C:#include <stdio.h> void main() { printf("%d %d\n",sizeof(5),sizeof(5,5)); printf("%d %d\n",sizeof(5),sizeof(5.0,5)); printf("%d %d\n",sizeof(5),sizeof(5,5.0)); }And...
View ArticleHow to vectorize and optimize this functions in C?
I have this functions, the result is correct but the compiler don't vectorize this.How can I achive that the compiler vectorize this and how can I optimize this codes?void LongNumSet( char *L, unsigned...
View Articlegfortran: error: libgfortran.spec: No such file or directory
I am attempting to install and run gfortran-8 on macOS with the following makefile. I installed it from http://hpc.sourceforge.net/ (8.3 version). I keep getting this error: gfortran: error:...
View Articlecrtatmega328p.o:(.init9+0x0): undefined reference to "main"
I have been trying to compile a robot simulation.I created an empty file called test.c and tried to compile a test using:avr-gcc -mmcu=atmega328p test.cAVR-GCC it's installedcopt@copt:~$ avr-gcc...
View ArticleSetting a C array as a new call stack (ESP) from inline asm?
As hinted from my title, I am interested if it would be possible to allocate a C array, and make it behave like a stack by pointing ESP register to it accordingly.Some code example...void foo(){ int x...
View ArticleInstall argon2 in Docker image (problem with installing gcc)
right now I'm trying to setup argon2 in a docker image. Apparently I have to install gcc before (and I don't just want to install it on my local machine). My Dockerfile looks like this:FROM...
View ArticleGCC force warning to be an error: excess elements in array initializer
My projects have to compile with two different compilers. One that creates a DLL (for a PC simulation, Mingw32-gcc-4.7.2) and another one that creates an ELF (for real hardware). Both compilers have...
View ArticleHow to see which flags -march=native will activate?
I'm compiling my C++ app using GCC 4.3. Instead of manually selecting the optimization flags I'm using -march=native, which in theory should add all optimization flags applicable to the hardware I'm...
View ArticleHow to know my code is running on CPU or GPU?
I am a beginner in OpenACC. I want to speed up my program by using OpenACC in fortran language with GCC compiler. my Code is :Program Test use openacc Implicit None...
View ArticleClik here to view.
An issue with the run configuration
I have an issue with the Eclipse.When I choose Generic MPICH2.... and local the option to choose connection is unclickable.
View Articlenm symbol output t vs T in a shared so library
I have added a new function (fuse_lowlevel_notify_inval_directory) in user space fuse library.The compilation and creation of libfuse.so is finished without error.But when my application tries to use...
View ArticleWhy compiler doesn't vectorize this function?
I executate the code with the comand gcc -O3 -ffast-math -msse -funroll-all-loops -ftree-vectorize -fopt-info-vec-missed -lm -g $1 -o ${2}.O3 but the compiler doesn't vectorized this function missed:...
View ArticleHow do I find out what error is occuring when installing 'diptest' with gcc...
I am trying to install something called 'diptest' from a local copy of this https://github.com/alimuldal/diptest on centos via the command line. I have installed everything I can for gcc. The gcc...
View ArticleFor a given source file, how to see the chain of #include substitutions a...
A similar question exists here C/C++: How to figure out the chain of header files for a given definition?, but mine is different in that I do not use Visual Studio, (I use GCC and Clang).
View ArticleGetting undefined reference when trying to build using gcc
I am trying to build a C++ static library in Linux (Ubuntu 18.04 in my case) using GCC using a Makefile. I noticed the issue is not with the makefile itself but the way I'm trying to compile and build...
View ArticleWhy does unaligned access to mmap'ed memory sometimes segfault on AMD64?
I have this piece of code which segfaults when run on Ubuntu 14.04 on an AMD64 compatible CPU:#include <inttypes.h>#include <stdlib.h>#include <sys/mman.h>int main(){ uint32_t sum =...
View Article