llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-mlir Author: Jerry Wu (pzread) <details> <summary>Changes</summary> Adds a new method `replaceWithZeroTripCheck` to `LoopLikeOpInterface`, to create zero-trip-check around the loop The purpose is to let loop ops (e.g. `scf.while`, `scf.for`) implement their own transformations to add zero-trip-check. The zero-trip-check creates a guard (e.g. `scf.if`) around the loop and the condition will be true only if the loop body will run at least once. An example usage is to hoist resource-intense loop invariants into this guard region so they will only run once but also not run when the loop body won't run at all. The implementation of `scf.while` can be found in the follow-up change: #<!-- -->80349 --- Full diff: https://github.com/llvm/llvm-project/pull/80331.diff 1 Files Affected: - (modified) mlir/include/mlir/Interfaces/LoopLikeInterface.td (+22) ``````````diff diff --git a/mlir/include/mlir/Interfaces/LoopLikeInterface.td b/mlir/include/mlir/Interfaces/LoopLikeInterface.td index e2ac85a3f7725..77409cb3a8274 100644 --- a/mlir/include/mlir/Interfaces/LoopLikeInterface.td +++ b/mlir/include/mlir/Interfaces/LoopLikeInterface.td @@ -220,6 +220,28 @@ def LoopLikeOpInterface : OpInterface<"LoopLikeOpInterface"> { /*defaultImplementation=*/[{ return ::mlir::failure(); }] + >, + InterfaceMethod<[{ + Add a zero-trip-check around the loop to check if the loop body is ever + run and return the new loop inside the check. The loop body is moved + over to the new loop. Returns "failure" if the loop doesn't support + this transformation. + + After the transformation, the ops inserted to the parent region of the + loop are guaranteed to be run only if the loop body runs at least one + iteration. + + Note: Ops in the loop body might be rearranged because of loop rotating + to maintain the semantic. Terminators might be removed/added during this + transformation. + }], + /*retTy=*/"::mlir::FailureOr<::mlir::LoopLikeOpInterface>", + /*methodName=*/"replaceWithZeroTripCheck", + /*args=*/(ins "::mlir::RewriterBase &":$rewriter), + /*methodBody=*/"", + /*defaultImplementation=*/[{ + return ::mlir::failure(); + }] > ]; `````````` </details> https://github.com/llvm/llvm-project/pull/80331 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
