I have been using clang for quite a while, and I can use clang -fno-builtin -emit-llvm -c hello.c to prevent the generation of llvm built-in functions, such as llvm.memset.
Recently, I switched to gcc with DragonEgg, since the program to be built is originally designed to be compiled with gcc. I searched on the web, but did not find any information about how to set DragonEgg parameters.
Could anyone please give me some help? Any hint or reference will be welcomed. Thanks!
I have figured out a way to use gcc + DragonEgg to achieve similar effects myself.
gcc -S -c -O0 -fplugin=$(DRAGONEGG_SO) -fplugin-arg-dragonegg-emit-ir hello.c -o hello.bc
opt -O3 -disable-simplify-libcalls hello.bc -o hello.bc
$(DRAGONEGG_SO) is the path to dragonegg.so.
Basically the LLVM intrinsics are added by the optimization pass instcombine. With -disable-simplify-libcalls, the LLVM intrinsics are prevented from generating in instcombine.
The method should also work for llvm-gcc to generate LLVM IR without LLVM intrinsics.
Related
I'm doing all this on a VLE and below is what I'm working with:
Running OS: Linux Centos 7
GCC:4.8.5 & 7.1.0
I'm trying to use GNU autotools (libtool, autoconf, automake) to build a project in 32-bit using gcc-7.1.0. Also, as a requirement, I must do this on Centos 7 and use gcc-7.1.0.
Apparently, the latest version of gcc that can be officially upgraded through yum is 4.8.5. However, I successfully installed gcc-7.1.0 from the official source and even included --enable-multiarch --with-list-multilib=m32,m64 --enable-multilib during configure.
The issue I'm running into is that the autotools seem to want to use the 64-bit libraries even though I'm including -m32 compiler switch in CXXFLAGS, CFLAGS, and LDFLAGS. The reason I think it's using 64-bit libraries at linking is that I get the error below:
libtool: link: g++ -m32 -fPIC -Wall -Wextra -Weffc++ -Werror -std=c++03 -O2 -o fldprog fldprog-icpprog.o ../../ ../seal3/fld/src/.libs/libbsp_fld.a -lpci /usr/local/lib/../lib64/libstdc++.so -lm -Wl,-rpath -Wl,/usr/local/lib /../lib64 -Wl,-rpath -Wl,/usr/local/lib/../lib64
/usr/local/lib/../lib64/libstdc++.so: error adding symbols: File in wrong format
And when I rename /usr/local/lib64 to lib64_something, the program will compile without any errors. However, I want to find a permanent solution.
I've searched the internet for answers but none of them seem to really work. I've tried including -L/usr/local/lib to AM_LDFLAGS, AM_CFLAGS in configure.ac
I'd appreciate any input. Thank you.
Edit:Revised
how can I use pthread_spinlock_t in gcc 4.6.3?
Which flags do I have to specify at compile time?
I'm using Ubuntu 12.04!
Thanks
Just add the option -pthread or -lpthread when linking.
Options -std=c99/c11 will restrict the available library functions to those of C99/C11 standard library
For getting C99/C11 languages features/library and and POSIX (and some BSD and some GNU extension) APIs, one can use -std=gnu99 or -std=gnu11 option to GCC.
I'm currently trying to compile a dynamically linked library (for a plugin system) using Windows and MinGW.
I compile each objects using this command line :
mingw-g++ -fPIC test.cpp
And the library using this line:
mingw-g++ -rdynamic -shared -Wl,-soname,test.so.1 -o test.so test.o
It doesn't work at all (using GCC with Linux, a similar line works though) : fPIC and rdynamic are ignored for some reason.
And while trying to make the library, it fails because the compiler try to link it with objects that are supposed to be resolved as I dynamically link it with the main binary.
So how do you compile this using MinGW?
Thanks :) !
-fPIC and -rdynamic are ignored because they are unused for Windows.
Also, .so is not the correct output extension for libraries on Windows.
To make a shared library for/on windows with GCC:
mingw-g++ -c file.cpp -o file.o
mingw-g++ -shared -Wl,--out-implib,libfile.a -o file.dll file.o
No more, no less.
And, documentation is always lovely to have: http://www.mingw.org/wiki/sampleDLL
I need compile a piece of C code to be called from matlab (mex compiling).
I am doing that on an intel mac and, since I am using Matlab's R2010a (7.10.0.499), I'd like to compile the C code into a version for 64-bits.
For whatever reason, just doing mex with the -arch=maci64 option did not seem to work...
As a way around, I am compiling the C code to a mexmaci64 file directly on the command line.
I used the gcc calls made by mex (with the -v option on) as a starting point.
I managed to compile the C code to an object file, but it looks like I am not compiling the C code to the correct architecture.
Does anyone know how to correct the gcc calls below so the C code gets compiled to 64-bits intel macs?
Details are listed below.
As always, any help greatly appreciated...
Keep thirsty, my friends. :p
G
DETAILS:
Here is how I did the compilation and linking:
gcc -c -I/Applications/MATLAB_R2010a.app/extern/include -DMATLAB_MEX_FILE -fno-common -no-cpp-precomp -fexceptions -D MACVERSION -DMX_COMPAT_32 -O3 -DNDEBUG "BoxQP.c"
gcc -O -bundle -Wl,-flat_namespace -undefined suppress -Wl,-exported_symbols_list,/Applications/MATLAB_R2010a.app/extern/lib/maci64/mexFunction.map -o "BoxQP.mexmaci64" BoxQP.o -L/Applications/MATLAB_R2010a.app/bin/maci64 -lmx -lmex -lmat -lstdc++
Here are the warnings I get:
ld warning: in /Applications/MATLAB_R2010a.app/bin/maci64/libmx.dylib, file is not of required architecture
ld warning: in /Applications/MATLAB_R2010a.app/bin/maci64/libmex.dylib, file is not of required architecture
ld warning: in /Applications/MATLAB_R2010a.app/bin/maci64/libmat.dylib, file is not of required architecture
Ignoring the warnings and calling the BoxQP function from matlab results in the following error message:
??? Invalid MEX-file '/Users/gvrocha/Documents/academic/projects/splice/code/matlab/covsel/BoxQP.mexmaci64':
dlopen(/Users/gvrocha/Documents/academic/projects/splice/code/matlab/covsel/BoxQP.mexmaci64, 1): no suitable image found.
Did find: /Users/gvrocha/Documents/academic/projects/splice/code/matlab/covsel/BoxQP.mexmaci64: mach-o, but wrong architecture.
PS: I tried changing the -DMX_COMPAT_32 flag to -DMX_COMPAT_64 but I do get the same warnings and same error...
PPS: I guess it may be relevant to mention that I am using Mac OS X 10.5.8 (the "tropical"/plain-vanilla Leopard, i.e., not the snow Leopard).
PPPS: The same happens with the yprime.c example provided by MATLAB
I have a pthreads program. I have to compile it with gcc -pthread in Linux (-pthreads is unrecognized option) and gcc -pthreads in Sun (-pthread is unrecognized option). Why the difference, since it's the same compiler? However, -lpthread works on both, but I heard this isn't always sufficient.
The Solaris -pthreads and Linux -pthread options do equivalent things. Apparently, gcc-4.x series accepts -pthread for Solaris as well.
You do want the -pthread/-pthreads option while compiling because it adds multithreading support in the preprocessor and the linker.