Thanks @kiranktp for working on this. Looks OK to me.

Thanks for the reviews. Committing with changes suggested.

Just wanted to check whether @rriddle has more comments on this patch.

Will tests come in a later patch?

Do @rriddle and @ftynse require further changes?

Added LLVMFrontendOpenMP and MLIROpenMP to the dependency of MLIRLLVMIR and also linking these libraries along with MLIRLLVMIR. Removed from other clients.

This revision includes the following changes,
-> Rebased.
-> Removed the enable-openmp flag.
-> Addressed review comments from @ftynse.

In D72962#1872745, @compiler_developer wrote:

In D72962#1872679, @kiranchandramohan wrote:

In D72962#1872562, @compiler_developer wrote:

Thanks for your comments.

MLIROpenMP and LLVMFrontendOpenMP libraries looks like an additional dependency for MLIR users who wants LLVM lowering and doesn't want anything to do with the OpenMP! I think Toy example cmake file changes is one of the early symptoms.

One way to handle that would be to go back to the first version of this patch which implements translation by deriving from public LLVM::ModuleTranslation.

I think conversion patterns would be more appropriate. But, I think, that is dependent on the decision to emit LLVM IR instead of LLVM Dialect.

In D72962#1872562, @compiler_developer wrote:

Thanks for your comments.

LGTM. You can wait for a day in case other reviewers have comments.

Looks OK to me.
Couple of comments inline.

Had a quick look today. Will spend some more time tomorrow.
Please see a few comments inline.

Thanks @ftynse for the comments. I will make a patch soon to address comments. The only question is regarding the necessity of the flag. Please see comment inline.

In D72400#1840949, @rriddle wrote:

I don't remember that we ever fully resolved this(adding OpenMP Dialect). Can you make a ping on llvm.discourse.group to make sure?

The enable-openmp flag is now local to file mlir/lib/Target/LLVMIR/ModuleTranslation.cpp. Added a function to lazily create the OpenMPIR builder when an OpenMP dialect op is detected.

I have taken @rriddle's suggestion and moved the translation into the LLVM translator. Also using unique pointer for the OpenMPIRBuilder. I believe this fixes the null pointer issue pointed out by @jdoerfert.

In this patch the code for translation is added to the existing LLVM dialect translation to LLVM IR. A new flag enable-openmp is used to enable the OpenMP translation.

Made changes suggested by the clang-format bot.

Thanks @eli.friedman.
@fpetrogalli are you OK with the changes I made to your suggestions? Might need some handholding to land this patch.

In general, I also worry that i might have missed some checks. I was hoping to get some pointers on how to run some tests so that we can minimise this. At the same time, I also feel that this change should not cause regressions.

Addressed review comments.

1. Adding a test
2. Change emitFlush to CreateFlush in OpenMPIRBuilder.cpp
3. Use updateLoc
4. Fixed formatting

Apologies, will wait for the reviews.

Does this patch need additional reviews or changes?

Addressed review comments by @fpetrogalli and @eli.friedman,

1. Fixed formatting in llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
2. Updated test to work with minimal attributes and removed prefixes for checks

Thanks @fpetrogalli, @eli.friedman for the review.

Thanks @jdoerfert for working on this.

Some minor comments about Filetypes and file extensions. Can be ignored or considered for a separate commit.