Developer Guide and Reference

Contents

Managing Libraries

Managing Libraries on Linux*

During compilation, the compiler reads the
LIBRARY_PATH
environment variable for static libraries it needs to link when building the executable. At runtime, the executable will link against dynamic libraries referenced in the
LD_LIBRARY_PATH
environment variable.

Modifying LIBRARY_PATH

If you want to add a directory,
/libs
for example, to the
LIBRARY_PATH
, you can do either of the following:
  • Command line:
    prompt>
    export LIBRARY_PATH=/libs:$LIBRARY_PATH
  • Startup file:
    export LIBRARY_PATH=/libs:$LIBRARY_PATH
To compile
file.cpp
and link it with the library
mylib.a
, enter the following command:
//on Linux [invocation] file.cpp mylib.a
With [invocation] being
icpx
or
dpcpp
.
The compiler passes file names to the linker in the following order:
  1. To the object file.
  2. To any objects or libraries specified at the command line, in a response file, or in a configuration file.
  3. To the Intel® Math Library,
    libimf.a
    .
By default, the
Intel® oneAPI
DPC++/C++
Compiler
uses the GNU* implementation of the C++ Standard Library (libstdc++) on OS* X v10.8, and libc++ implementation on OS* X v10.9. You can change the default using the
-stdlib
option:
-stdlib=libc++ //to switch to libc++ -stdlib=libstdc++ //to switch to libstdc++

Compile with DPC++ and Link Other Compilers

When you use the
dpcpp
compiler and source its entire environment, then linking works correctly with other compilers if the correct path to the compiler libraries is set. This allows programs to be compiled with DPC++ and then linked with other compilers (example:
gcc
). If you try to do this without sourcing the compiler environment, the linking fails with undefined references in
libsycl.so
and other internal libraries.
To resolve this, add the following paths to
LD_LIBRARY_PATH
:
<install_dir>/compiler/latest/linux/compiler/lib/intel64 <install_dir>/compiler/latest/linux/lib <install_dir>/compiler/latest/linux/lib/x64 <install_dir>/tbb/latest/lib/intel64/gcc4.8

Managing Libraries on Windows*

The
LIB
environment variable contains a semicolon-separated list of directories in which the Microsoft* linker will search for library (
.lib
) files. The compiler does not specify library names to the linker, but includes directives in the object file to specify the libraries to be linked with each object.
For more information on adding library names to the response file and the configuration file, see Using Response Files and Using Configuration Files.
To specify a library name on the command line, you must first add the library's path to the
LIB
environment variable. Then, to compile
file.cpp
and link it with the library
mylib.lib
, enter the following command:
[invocation] file.cpp mylib.lib
Where[
invocation
] is
icx
for C++ or
dpcpp-cl
for DPC++
.

Other Considerations

The Intel Compiler Math Libraries contain performance-optimized implementations for various Intel platforms. By default, the best implementation for the underlying hardware is selected at runtime. The library dispatch of multi-threaded code may lead to apparent data races, which may be detected by certain software analysis tools. However, as long as the threads are running on cores with the same CPUID, these data races are harmless and are not a cause for concern.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.