[Mlir-commits] [mlir] [mlir][affine] Add early exit to getLowerBound/getUpperBound function (NFC) (PR #212047)

[lonely eagle]

https://github.com/linuxlonelyeagle created https://github.com/llvm/llvm-project/pull/212047

When an AffineExpr is an AffineConstantExpr, its bound can be directly returned  without computing the lower/upper bounds for all operand values. This avoids  redundant bound evaluations on operands and speeds up static bound computation.

>From 728fbec02a34b0019242fb9f731ea41d05df4971 Mon Sep 17 00:00:00 2001
From: linuxlonelyeagle <2020382038 at qq.com>
Date: Sat, 25 Jul 2026 17:35:07 +0000
Subject: [PATCH] add early exit to getUpperBound/getLowerBound function.

---
 mlir/lib/Dialect/Affine/IR/AffineOps.cpp | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
index defb029865835..fa5266affbd20 100644
--- a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
+++ b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
@@ -775,6 +775,9 @@ static std::optional<int64_t> getUpperBound(Value iv) {
 static std::optional<int64_t> getUpperBound(AffineExpr expr, unsigned numDims,
                                             unsigned numSymbols,
                                             ArrayRef<Value> operands) {
+  if (auto constExpr = dyn_cast<AffineConstantExpr>(expr))
+    return constExpr.getValue();
+
   // Get the constant lower or upper bounds on the operands.
   SmallVector<std::optional<int64_t>> constLowerBounds, constUpperBounds;
   constLowerBounds.reserve(operands.size());
@@ -784,9 +787,6 @@ static std::optional<int64_t> getUpperBound(AffineExpr expr, unsigned numDims,
     constUpperBounds.push_back(getUpperBound(operand));
   }
 
-  if (auto constExpr = dyn_cast<AffineConstantExpr>(expr))
-    return constExpr.getValue();
-
   return getBoundForAffineExpr(expr, numDims, numSymbols, constLowerBounds,
                                constUpperBounds,
                                /*isUpper=*/true);
@@ -798,6 +798,9 @@ static std::optional<int64_t> getUpperBound(AffineExpr expr, unsigned numDims,
 static std::optional<int64_t> getLowerBound(AffineExpr expr, unsigned numDims,
                                             unsigned numSymbols,
                                             ArrayRef<Value> operands) {
+  if (auto constExpr = dyn_cast<AffineConstantExpr>(expr))
+    return constExpr.getValue();
+
   // Get the constant lower or upper bounds on the operands.
   SmallVector<std::optional<int64_t>> constLowerBounds, constUpperBounds;
   constLowerBounds.reserve(operands.size());
@@ -807,15 +810,9 @@ static std::optional<int64_t> getLowerBound(AffineExpr expr, unsigned numDims,
     constUpperBounds.push_back(getUpperBound(operand));
   }
 
-  std::optional<int64_t> lowerBound;
-  if (auto constExpr = dyn_cast<AffineConstantExpr>(expr)) {
-    lowerBound = constExpr.getValue();
-  } else {
-    lowerBound = getBoundForAffineExpr(expr, numDims, numSymbols,
-                                       constLowerBounds, constUpperBounds,
-                                       /*isUpper=*/false);
-  }
-  return lowerBound;
+  return getBoundForAffineExpr(expr, numDims, numSymbols, constLowerBounds,
+                               constUpperBounds,
+                               /*isUpper=*/false);
 }
 
 /// Simplify `expr` while exploiting information from the values in `operands`.