The -par-threshold{n} (Linux*) or /Qpar-threshold[:n] (Windows*) option sets a threshold for auto-parallelization of loops based on the probability of profitable execution of the loop in parallel. The value of n can be from 0 to 100.
The -par-report (Linux) or /Qpar-report (Windows) option controls the diagnostic levels 0, 1, 2, or 3 of the auto-parallelizer. Specify level 3 to get the most information possible from the option.
For example, assume you want a full diagnostic report on the following example code:
Example 1: Sample code |
|---|
|
void no_par(void) { int i; int a[1000]; for (i=1; i<1000; i++) { a[i] = (i * 2) % i * 1 + sqrt(i); a[i] = a[i-1] + i; } } |
You can use -par-report3 (Linux) or /Qpar-report3 (Windows) by entering a command similar to the following:
Platform |
Commands |
|---|---|
|
Linux |
icpc -parallel -par-report3 -c diag_prog.c |
|
Windows |
icl /Qparallel /Qpar-report3 /c diag_prog.c |
where -c (Linux) or /c (Windows) instructs the compiler to compile the example without generating an executable.
The following example output illustrates the diagnostic report generated by the compiler for the example code shown above.
Example 2: Sample Code Report Output |
|---|
|
procedure: no_par serial loop: line 29 flow data dependence from line 30 to line 31, due to "a" flow data dependence from line 31 to line 31, due to "a" |