The documentation is unfortunately out of date. I still hope to find a
beginner volunteer who knows best what they need to understand and can
update it. At the moment a lot is changing because of the transition
to the new pass manager.
If there is no output it means that no Scops have been optimized. For
instance a common problem is that clang without optimization level
emits "noopt" into the .ll file skipping all optimizations.
For instance, what I get:
```
$ ./opt -polly-ast -polly-print-ast -disable-output matmul.preopt.ll
-polly-process-unprofitable
Printing analysis 'Polly - Generate an AST from the SCoP (isl)' for
region: 'for.cond1.preheader => for.end28' in function 'kernel_gemm':
Printing analysis 'Polly - Generate an AST of the SCoP
(isl)'for.cond1.preheader => for.end28' in function 'kernel_gemm':
:: isl ast :: kernel_gemm :: %for.cond1.preheader---%for.end28
if (p_0 <= 1024 && p_1 <= 1024 && (&MemRef4[p_1 - 1][p_0] <=
&MemRef0[0][0] || &MemRef0[p_2 - 1][p_0] <= &MemRef4[0][0]) &&
(&MemRef2[p_2 - 1][p_1] <= &MemRef0[0][0] || &MemRef0[p_2 - 1][p_0] <=
&MemRef2[0][0]))
// Loop with Metadata
for (int c0 = 0; c0 < p_2; c0 += 1) {
// Loop with Metadata
for (int c1 = 0; c1 < p_0; c1 += 1) {
Stmt2(c0, c1);
// Loop with Metadata
for (int c2 = 0; c2 < p_1; c2 += 1)
Stmt4(c0, c1, c2);
}
}
else
{ /* original code */ }
```
Options to print what is going on include `-debug`,
`-polly-print-detect`, `-polly-print-scops`, `-polly-report` and `O3
-polly -polly-show`.
Michael
> To view this discussion on the web, visit
https://groups.google.com/d/msgid/polly-dev/1859f2ae-6120-417e-aecf-2b88e3df0d61n%40googlegroups.com.
--
Tardyzentrismus verboten!