llvm dev - May 2021 - Adding LoopNest case to getIRName

Looks like even in LoopNest mode, FunctionToLoopPassAdaptor passes a Loop
to PassInstrumentation. But LoopPassManager::runSinglePass either passes a
Loop or LoopNest. Seems like that should be fixed to always pass the Loop
to PassInstrumentation.

On Tue, May 11, 2021 at 11:26 PM raghesh via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hi All
>
> While working on a LoopNest pass, I hit 'unreachable code' in the
> getIRName, which is invoked as part of debugging options (like
> -debug-pass-manager). It is figured out that within getIRName, LoopNest is
> not handled. I could fix it with the following patch.
>
> diff --git a/llvm/lib/Passes/StandardInstrumentations.cpp
> b/llvm/lib/Passes/StandardInstrumentations.cpp
> index e64df0b1147f..65e0e7d4cf27 100644
> --- a/llvm/lib/Passes/StandardInstrumentations.cpp
> +++ b/llvm/lib/Passes/StandardInstrumentations.cpp
> @@ -20,6 +20,7 @@
>  #include "llvm/Analysis/LazyCallGraph.h"
>  #include "llvm/Analysis/LoopInfo.h"
>  #include "llvm/IR/Function.h"
> +#include "llvm/Analysis/LoopNestAnalysis.h"
>  #include "llvm/IR/Module.h"
>  #include "llvm/IR/PassInstrumentation.h"
>  #include "llvm/IR/PassManager.h"
> @@ -285,6 +286,17 @@ std::string getIRName(Any IR) {
>      return OS.str();
>    }
>
> +  if (any_isa<const LoopNest *>(IR)) {
> +    const Loop *L = &any_cast<const LoopNest
*>(IR)->getOutermostLoop();
> +    std::string S;
> +    raw_string_ostream OS(S);
> +    assert(L && "Loop should be valid for printing");
> +    L->print(OS, /*Verbose*/ false, /*PrintNested*/ false);
> +    return OS.str();
> +  }
> +
>    llvm_unreachable("Unknown wrapped IR type");
>  }
>
> Just wanted to make sure that this is the right fix and if it is so we can
> upstream this change.
>
> Regards,
> ------------------------------
> Raghesh Aloor
> AMD India Pvt. Ltd.
> Bengaluru.
> ------------------------------
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20210512/e8078b9c/attachment.html>

Hi Arthur,

Thanks for that update. Do you mean to say that runSinglePass is a (one of
the) common place(s) where we can pass the Loop to PassInstrumentation even
in LoopNest Mode? That would be ideal rather than updating
PassInstrumentation as I could see other places also (similar to the
following) where we should do the same.

--- a/llvm/lib/Passes/StandardInstrumentations.cpp
+++ b/llvm/lib/Passes/StandardInstrumentations.cpp
@@ -861,6 +861,13 @@ bool OptNoneInstrumentation::shouldRun(StringRef
PassID, Any IR) {
   } else if (any_isa<const Loop *>(IR)) {
     F = any_cast<const Loop *>(IR)->getHeader()->getParent();
   }
+  else  if (any_isa<const LoopNest *>(IR)) {
+    const Loop *L = &any_cast<const LoopNest
*>(IR)->getOutermostLoop();
+    F = L->getHeader()->getParent();
+  }
+
   bool ShouldRun = !(F && F->hasOptNone());
   if (!ShouldRun && DebugLogging) {
     errs() << "Skipping pass " << PassID << "
on " << F->getName()

Regards,
------------------------------
Raghesh Aloor
AMD India Pvt. Ltd.
Bengaluru.
------------------------------


On Wed, May 12, 2021 at 10:07 PM Arthur Eubanks <aeubanks at google.com>
wrote:
> Looks like even in LoopNest mode, FunctionToLoopPassAdaptor passes a Loop
> to PassInstrumentation. But LoopPassManager::runSinglePass either passes a
> Loop or LoopNest. Seems like that should be fixed to always pass the Loop
> to PassInstrumentation.
>
> On Tue, May 11, 2021 at 11:26 PM raghesh via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Hi All
>>
>> While working on a LoopNest pass, I hit 'unreachable code' in
the
>> getIRName, which is invoked as part of debugging options (like
>> -debug-pass-manager). It is figured out that within getIRName, LoopNest
is
>> not handled. I could fix it with the following patch.
>>
>> diff --git a/llvm/lib/Passes/StandardInstrumentations.cpp
>> b/llvm/lib/Passes/StandardInstrumentations.cpp
>> index e64df0b1147f..65e0e7d4cf27 100644
>> --- a/llvm/lib/Passes/StandardInstrumentations.cpp
>> +++ b/llvm/lib/Passes/StandardInstrumentations.cpp
>> @@ -20,6 +20,7 @@
>>  #include "llvm/Analysis/LazyCallGraph.h"
>>  #include "llvm/Analysis/LoopInfo.h"
>>  #include "llvm/IR/Function.h"
>> +#include "llvm/Analysis/LoopNestAnalysis.h"
>>  #include "llvm/IR/Module.h"
>>  #include "llvm/IR/PassInstrumentation.h"
>>  #include "llvm/IR/PassManager.h"
>> @@ -285,6 +286,17 @@ std::string getIRName(Any IR) {
>>      return OS.str();
>>    }
>>
>> +  if (any_isa<const LoopNest *>(IR)) {
>> +    const Loop *L = &any_cast<const LoopNest
*>(IR)->getOutermostLoop();
>> +    std::string S;
>> +    raw_string_ostream OS(S);
>> +    assert(L && "Loop should be valid for
printing");
>> +    L->print(OS, /*Verbose*/ false, /*PrintNested*/ false);
>> +    return OS.str();
>> +  }
>> +
>>    llvm_unreachable("Unknown wrapped IR type");
>>  }
>>
>> Just wanted to make sure that this is the right fix and if it is so we
>> can upstream this change.
>>
>> Regards,
>> ------------------------------
>> Raghesh Aloor
>> AMD India Pvt. Ltd.
>> Bengaluru.
>> ------------------------------
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20210513/e59f9caa/attachment.html>