[Mlir-commits] [mlir] [mlir][transform] Plumb a simplified form of AffineMin folding into t… (PR #145170)

[Kunwar Grover]

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@@ -1042,6 +1046,59 @@ simplifyMapWithOperands(AffineMap &map, ArrayRef<Value> operands) {
                        map.getContext());
 }
 
+/// Assuming `dimOrSym` is a quantity in `map` that is defined by `minOp`,
+/// replaces the patterns:
+/// ```
+///   dimOrSym.ceildiv(cst) * cst
+///   (dimOrSym + cst - 1).floordiv(cst) * cst
+/// ```
+/// by `cst` in `map`.
+/// This simplification is valid iff `minOp` is guaranteed to be nonnegative.
+/// Additionally, allows the caller to pass `affineMinKnownToBeNonNegative` to
+/// inject static information that may not be statically discoverable.
+/// Warning: ValueBoundsConstraintSet::computeConstantBound is needed to check
+/// for the nonnegative case, if `affineMinKnownToBeNonNegative` is false.
+static LogicalResult replaceAffineMinBoundingBoxExpression(
+    AffineMinOp minOp, AffineExpr dimOrSym, AffineMap *map,
+    bool affineMinKnownToBeNonNegative = false) {
+  auto affineMinMap = minOp.getAffineMap();
+  if (!affineMinKnownToBeNonNegative) {
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Groverkss wrote:

I really think we should add an attribute on affine.min that indicates if the result is positive. We use it so much for loop tile calculation that it might be worth having it some day.

https://github.com/llvm/llvm-project/pull/145170