[Mlir-commits] [mlir] [mlir] Extend SCF loopUnrollByFactor to return the result loops (PR #114573)

[Thomas Raoux]

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@@ -111,11 +111,13 @@ LogicalResult coalescePerfectlyNestedSCFForLoops(scf::ForOp op);
 void collapseParallelLoops(RewriterBase &rewriter, scf::ParallelOp loops,
                            ArrayRef<std::vector<unsigned>> combinedDimensions);
 
-/// Unrolls this for operation by the specified unroll factor. Returns failure
-/// if the loop cannot be unrolled either due to restrictions or due to invalid
-/// unroll factors. Requires positive loop bounds and step. If specified,
-/// annotates the Ops in each unrolled iteration by applying `annotateFn`.
-LogicalResult loopUnrollByFactor(
+/// Unrolls this for operation by the specified unroll factor. Returns the
+/// unrolled main loop and the eplilog loop in sequence, if the loop is
+/// unrolled. Otherwise returns an empty vector if the loop cannot be unrolled
+/// either due to restrictions or due to invalid unroll factors. Requires
+/// positive loop bounds and step. If specified, annotates the Ops in each
+/// unrolled iteration by applying `annotateFn`.
+SmallVector<scf::ForOp> loopUnrollByFactor(
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ThomasRaoux wrote:

I would prefer to make it explicit in the code rather than relying on comments

https://github.com/llvm/llvm-project/pull/114573