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

[llvmlistbot at llvm.org]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-mlir-affine

Author: lonely eagle (linuxlonelyeagle)

<details>
<summary>Changes</summary>

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.

---
Full diff: https://github.com/llvm/llvm-project/pull/212047.diff


1 Files Affected:

- (modified) mlir/lib/Dialect/Affine/IR/AffineOps.cpp (+9-12) 


``````````diff
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`.

``````````

</details>


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