[Mlir-commits] [mlir] [MLIR][Affine] Simplify affine.for bounds by pruning redundant expressions via ValueBoundsConstraintSet (PR #199032)

[Oleksandr Alex Zinenko]

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@@ -218,11 +218,105 @@ struct SimplifyDelinearizeOfLinearizeDisjoint final
   }
 };
 
+/// Simplifies the affine map results by eliminating redundant expressions.
+///
+/// This function performs a pairwise comparison of all expressions in the map
+/// using the analysis from `ValueBoundsConstraintSet`. If an expression `a` is
+/// statically proven to be strictly bounded or covered by another expression
+/// `b` (based on the given comparison operator `cmp`), `a` is considered
+/// redundant and is safely pruned from the results. NOTE: We iterate backwards
+/// (from size-1 down to 0) to safely erase elements from the `SmallVector`
+/// without causing iterator invalidation or indexing shifts for upcoming
+/// elements.
+static SmallVector<AffineExpr>
+simplifyRedundantMapResults(AffineMap map, SmallVector<Value> operands,
+                            ValueBoundsConstraintSet::ComparisonOperator cmp) {
+  SmallVector<AffineExpr> mapResults(map.getResults());
+  auto *context = map.getContext();
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ftynse wrote:

Almost always avoid auto. Acceptable uses are casts, constructors, iterators and lambdas.

https://github.com/llvm/llvm-project/pull/199032