Intelcompiler

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Intel compiler

Intel compiler web page The Intel compiler is installed as an alternative fortran compiler. The executable binaries are installed at /site/intel/bin/ and the different programs that is most commonly used are : ifort, icc and iCC. The associated libraries can be found at /site//site/intel/fce/ (fce is the 64 bit versions while fc is the 32 bit versions).

Compiler flags

The most common compiler flags are (try ifort -help to get an overview) :

• -c just compile, do not attempt linking
• -O2 Turn on extensive optimization. This is the default.
• -O3 Turn on aggressive optimization.
• -fast Equivalent to -xT -O3 -ipo -no-prec-div -static
• -xW for processors that have only SSE2
• -xP for processors that support SSE3
• -w Suppress all warnings

Normally the Intel fortran compiler generate reasoably efficient code with just the standard compiler flags like -O2 etc. For more information refer to man ifort etc, or the manual found at the Portland web page or the user guide at /site/ on titan.

The Intel fortran compilers add a single underscore "_" to symbols. The nm utility can be used to list the symbols in an object file.

[olews@login-0-0 f77]$ nm realft.o
0000000000000000 T realft_
                 U sin
[olews@login-0-0 f77]$