[Mlir-commits] [mlir] add iterVarKind for convenient iterating over variables (PR #152091)

[Jeremy Kun]

https://github.com/j2kun created https://github.com/llvm/llvm-project/pull/152091

I find myself doing this alot

```
for (unsigned varIndex = rel.getVarKindOffset(VarKind::Domain);
     varIndex < rel.getVarKindEnd(VarKind::Domain); ++varIndex) {
  ...
}
```

Adding this convenience method so I can instead do

```
for (unsigned varIndex : rel.iterVarKind(VarKind::Domain)) {
  ...
}
```

>From f20a5c5c8f31b5c6a8ec21aac85b41761d44709c Mon Sep 17 00:00:00 2001
From: Jeremy Kun <j2kun at users.noreply.github.com>
Date: Mon, 4 Aug 2025 23:03:03 -0700
Subject: [PATCH] add iterVarKind for convenient iterating over variables

---
 .../mlir/Analysis/Presburger/IntegerRelation.h        |  7 +++++++
 .../Analysis/Presburger/IntegerRelationTest.cpp       | 11 +++++++++++
 2 files changed, 18 insertions(+)

diff --git a/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h b/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
index ee401cca8f552..fb895b1a6fb78 100644
--- a/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
+++ b/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
@@ -20,6 +20,7 @@
 #include "mlir/Analysis/Presburger/PresburgerSpace.h"
 #include "mlir/Analysis/Presburger/Utils.h"
 #include "llvm/ADT/DynamicAPInt.h"
+#include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/LogicalResult.h"
 #include <optional>
@@ -268,6 +269,12 @@ class IntegerRelation {
     return space.getVarKindEnd(kind);
   }
 
+  /// Return an interator over the variables of the specified kind
+  /// starting at the relevant offset.
+  auto iterVarKind(VarKind kind) {
+    return llvm::seq(getVarKindOffset(kind), getVarKindEnd(kind));
+  }
+
   /// Get the number of elements of the specified kind in the range
   /// [varStart, varLimit).
   unsigned getVarKindOverlap(VarKind kind, unsigned varStart,
diff --git a/mlir/unittests/Analysis/Presburger/IntegerRelationTest.cpp b/mlir/unittests/Analysis/Presburger/IntegerRelationTest.cpp
index dd0b09f7f05d2..818dcfd578e48 100644
--- a/mlir/unittests/Analysis/Presburger/IntegerRelationTest.cpp
+++ b/mlir/unittests/Analysis/Presburger/IntegerRelationTest.cpp
@@ -16,6 +16,7 @@
 
 using namespace mlir;
 using namespace presburger;
+using ::testing::ElementsAre;
 
 TEST(IntegerRelationTest, getDomainAndRangeSet) {
   IntegerRelation rel = parseRelationFromSet(
@@ -702,3 +703,13 @@ TEST(IntegerRelationTest, rangeProductSymbols) {
 
   EXPECT_TRUE(expected.isEqual(rangeProd));
 }
+
+TEST(IntegerRelationTest, getVarKindRange) {
+  IntegerRelation r1 = parseRelationFromSet(
+      "(i1, i2, i3, i4, i5) : (i1 >= 0, i2 >= 0, i3 >= 0, i4 >= 0, i5 >= 0)", 2);
+  SmallVector<unsigned> actual;
+  for (unsigned var : r1.iterVarKind(VarKind::Range)) {
+    actual.push_back(var);
+  }
+  EXPECT_THAT(actual, ElementsAre(2, 3, 4));
+}