[Mlir-commits] [mlir] [mlir][loops] Reland Refactor LoopFuseSiblingOp and support parallel fusion #94391 (PR #97607)

[Ivan Butygin]

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@@ -113,3 +115,58 @@ LogicalResult detail::verifyLoopLikeOpInterface(Operation *op) {
 
   return success();
 }
+
+LoopLikeOpInterface mlir::createFused(LoopLikeOpInterface target,
+                                      LoopLikeOpInterface source,
+                                      RewriterBase &rewriter,
+                                      NewYieldValuesFn newYieldValuesFn,
+                                      FuseTerminatorFn fuseTerminatorFn) {
+  auto targetIterArgs = target.getRegionIterArgs();
+  std::optional<SmallVector<Value>> targetInductionVar =
+      target.getLoopInductionVars();
+  SmallVector<Value> targetYieldOperands(target.getYieldedValues());
+  auto sourceIterArgs = source.getRegionIterArgs();
+  std::optional<SmallVector<Value>> sourceInductionVar =
+      *source.getLoopInductionVars();
+  SmallVector<Value> sourceYieldOperands(source.getYieldedValues());
+  auto sourceRegion = source.getLoopRegions().front();
+
+  FailureOr<LoopLikeOpInterface> maybeFusedLoop =
+      target.replaceWithAdditionalYields(rewriter, source.getInits(),
+                                         /*replaceInitOperandUsesInLoop=*/false,
+                                         newYieldValuesFn);
+  if (failed(maybeFusedLoop))
+    llvm_unreachable("failed to replace loop");
+  LoopLikeOpInterface fusedLoop = *maybeFusedLoop;
+  rewriter.moveOpBefore(fusedLoop, source);
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Hardcode84 wrote:

Can you add code comment, why this is needed?

https://github.com/llvm/llvm-project/pull/97607