Basic Concepts

LoopTool and LoopReport enable you to:

• Time all loops, whether serial or parallel.

• Produce a table of loop timings.

• Collect hints from the compiler during compilation.

• LoopTool displays a graph of loop runtimes and shows which loops were parallelized. You can go directly from the graphical display of loops to the source code for any loop you want, so you can edit your source code while in LoopTool.

• LoopReport reports loop runtimes in an ASCII file instead of a graphical display.

There are four basic steps for using LoopTool and LoopReport:

1. Setting up environment variables

2. Compiling the program with the options required to create a timing file for loop analysis

3. Running the program to generate a timing file

4. Invoke LoopTool or LoopReport on the timing file

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   Note -

   The examples in this section use the Fortran (f77 and f90) compilers. The options shown (such as -xparallel, -Zlp) also work for C.

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