[llvm] e6c2216 - Add ConstantRangeList::unionWith() and ::intersectWith() (#96547)

via llvm-commits llvm-commits at lists.llvm.org
Tue Jun 25 16:38:07 PDT 2024


Author: Haopeng Liu
Date: 2024-06-25T16:38:03-07:00
New Revision: e6c2216940885ae5b0d6509dac73417c40d6c62f

URL: https://github.com/llvm/llvm-project/commit/e6c2216940885ae5b0d6509dac73417c40d6c62f
DIFF: https://github.com/llvm/llvm-project/commit/e6c2216940885ae5b0d6509dac73417c40d6c62f.diff

LOG: Add ConstantRangeList::unionWith() and ::intersectWith() (#96547)

Add ConstantRangeList::unionWith() and ::intersectWith().

These methods will be used in the "initializes" attribute inference.

https://github.com/llvm/llvm-project/commit/df11106068294fb00f11988d3f48336e2cbed364

Added: 
    

Modified: 
    llvm/include/llvm/IR/ConstantRangeList.h
    llvm/lib/IR/ConstantRangeList.cpp
    llvm/unittests/IR/ConstantRangeListTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/ConstantRangeList.h b/llvm/include/llvm/IR/ConstantRangeList.h
index f696bd6cc6a3d..46edaff19e73f 100644
--- a/llvm/include/llvm/IR/ConstantRangeList.h
+++ b/llvm/include/llvm/IR/ConstantRangeList.h
@@ -72,6 +72,14 @@ class [[nodiscard]] ConstantRangeList {
                          APInt(64, Upper, /*isSigned=*/true)));
   }
 
+  /// Return the range list that results from the union of this
+  /// ConstantRangeList with another ConstantRangeList, "CRL".
+  ConstantRangeList unionWith(const ConstantRangeList &CRL) const;
+
+  /// Return the range list that results from the intersection of this
+  /// ConstantRangeList with another ConstantRangeList, "CRL".
+  ConstantRangeList intersectWith(const ConstantRangeList &CRL) const;
+
   /// Return true if this range list is equal to another range list.
   bool operator==(const ConstantRangeList &CRL) const {
     return Ranges == CRL.Ranges;

diff  --git a/llvm/lib/IR/ConstantRangeList.cpp b/llvm/lib/IR/ConstantRangeList.cpp
index 2cc483d4e4962..0373524a09f10 100644
--- a/llvm/lib/IR/ConstantRangeList.cpp
+++ b/llvm/lib/IR/ConstantRangeList.cpp
@@ -81,6 +81,95 @@ void ConstantRangeList::insert(const ConstantRange &NewRange) {
   }
 }
 
+ConstantRangeList
+ConstantRangeList::unionWith(const ConstantRangeList &CRL) const {
+  assert(getBitWidth() == CRL.getBitWidth() &&
+         "ConstantRangeList bitwidths don't agree!");
+  // Handle common cases.
+  if (empty())
+    return CRL;
+  if (CRL.empty())
+    return *this;
+
+  ConstantRangeList Result;
+  size_t i = 0, j = 0;
+  // "PreviousRange" tracks the lowest unioned range that is being processed.
+  // Its lower is fixed and the upper may be updated over iterations.
+  ConstantRange PreviousRange(getBitWidth(), false);
+  if (Ranges[i].getLower().slt(CRL.Ranges[j].getLower())) {
+    PreviousRange = Ranges[i++];
+  } else {
+    PreviousRange = CRL.Ranges[j++];
+  }
+
+  // Try to union "PreviousRange" and "CR". If they are disjoint, push
+  // "PreviousRange" to the result and assign it to "CR", a new union range.
+  // Otherwise, update the upper of "PreviousRange" to cover "CR". Note that,
+  // the lower of "PreviousRange" is always less or equal the lower of "CR".
+  auto UnionAndUpdateRange = [&PreviousRange,
+                              &Result](const ConstantRange &CR) {
+    if (PreviousRange.getUpper().slt(CR.getLower())) {
+      Result.Ranges.push_back(PreviousRange);
+      PreviousRange = CR;
+    } else {
+      PreviousRange = ConstantRange(
+          PreviousRange.getLower(),
+          APIntOps::smax(PreviousRange.getUpper(), CR.getUpper()));
+    }
+  };
+  while (i < size() || j < CRL.size()) {
+    if (j == CRL.size() ||
+        (i < size() && Ranges[i].getLower().slt(CRL.Ranges[j].getLower()))) {
+      // Merge PreviousRange with this.
+      UnionAndUpdateRange(Ranges[i++]);
+    } else {
+      // Merge PreviousRange with CRL.
+      UnionAndUpdateRange(CRL.Ranges[j++]);
+    }
+  }
+  Result.Ranges.push_back(PreviousRange);
+  return Result;
+}
+
+ConstantRangeList
+ConstantRangeList::intersectWith(const ConstantRangeList &CRL) const {
+  assert(getBitWidth() == CRL.getBitWidth() &&
+         "ConstantRangeList bitwidths don't agree!");
+
+  // Handle common cases.
+  if (empty())
+    return *this;
+  if (CRL.empty())
+    return CRL;
+
+  ConstantRangeList Result;
+  size_t i = 0, j = 0;
+  while (i < size() && j < CRL.size()) {
+    auto &Range = this->Ranges[i];
+    auto &OtherRange = CRL.Ranges[j];
+
+    // The intersection of two Ranges is (max(lowers), min(uppers)), and it's
+    // possible that max(lowers) > min(uppers) if they don't have intersection.
+    // Add the intersection to result only if it's non-empty.
+    // To keep simple, we don't call ConstantRange::intersectWith() as it
+    // considers the complex upper wrapped case and may result two ranges,
+    // like (2, 8) && (6, 4) = {(2, 4), (6, 8)}.
+    APInt Start = APIntOps::smax(Range.getLower(), OtherRange.getLower());
+    APInt End = APIntOps::smin(Range.getUpper(), OtherRange.getUpper());
+    if (Start.slt(End))
+      Result.Ranges.push_back(ConstantRange(Start, End));
+
+    // Move to the next Range in one list determined by the uppers.
+    // For example: A = {(0, 2), (4, 8)}; B = {(-2, 5), (6, 10)}
+    // We need to intersect three pairs: A0 && B0; A1 && B0; A1 && B1.
+    if (Range.getUpper().slt(OtherRange.getUpper()))
+      i++;
+    else
+      j++;
+  }
+  return Result;
+}
+
 void ConstantRangeList::print(raw_ostream &OS) const {
   interleaveComma(Ranges, OS, [&](ConstantRange CR) {
     OS << "(" << CR.getLower() << ", " << CR.getUpper() << ")";

diff  --git a/llvm/unittests/IR/ConstantRangeListTest.cpp b/llvm/unittests/IR/ConstantRangeListTest.cpp
index 144b5ccdc1fc0..b679dd3a33d5d 100644
--- a/llvm/unittests/IR/ConstantRangeListTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeListTest.cpp
@@ -94,4 +94,116 @@ TEST_F(ConstantRangeListTest, Insert) {
   EXPECT_TRUE(CRL == Expected);
 }
 
+ConstantRangeList GetCRL(ArrayRef<std::pair<APInt, APInt>> Pairs) {
+  SmallVector<ConstantRange, 2> Ranges;
+  for (auto &[Start, End] : Pairs)
+    Ranges.push_back(ConstantRange(Start, End));
+  return ConstantRangeList(Ranges);
+}
+
+TEST_F(ConstantRangeListTest, Union) {
+  APInt APN4 = APInt(64, -4, /*isSigned=*/true);
+  APInt APN2 = APInt(64, -2, /*isSigned=*/true);
+  APInt AP0 = APInt(64, 0, /*isSigned=*/true);
+  APInt AP2 = APInt(64, 2, /*isSigned=*/true);
+  APInt AP4 = APInt(64, 4, /*isSigned=*/true);
+  APInt AP6 = APInt(64, 6, /*isSigned=*/true);
+  APInt AP7 = APInt(64, 7, /*isSigned=*/true);
+  APInt AP8 = APInt(64, 8, /*isSigned=*/true);
+  APInt AP10 = APInt(64, 10, /*isSigned=*/true);
+  APInt AP11 = APInt(64, 11, /*isSigned=*/true);
+  APInt AP12 = APInt(64, 12, /*isSigned=*/true);
+  APInt AP16 = APInt(64, 16, /*isSigned=*/true);
+  APInt AP18 = APInt(64, 18, /*isSigned=*/true);
+  ConstantRangeList CRL = GetCRL({{AP0, AP4}, {AP8, AP12}});
+
+  // Union with a subset.
+  ConstantRangeList Empty;
+  EXPECT_EQ(CRL.unionWith(Empty), CRL);
+  EXPECT_EQ(Empty.unionWith(CRL), CRL);
+
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP0, AP2}})), CRL);
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP10, AP12}})), CRL);
+
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP0, AP2}, {AP8, AP10}})), CRL);
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP0, AP2}, {AP10, AP12}})), CRL);
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP2, AP4}, {AP8, AP10}})), CRL);
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP2, AP4}, {AP10, AP12}})), CRL);
+
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP0, AP4}, {AP8, AP10}, {AP11, AP12}})),
+            CRL);
+
+  EXPECT_EQ(CRL.unionWith(CRL), CRL);
+
+  // Union with new ranges.
+  EXPECT_EQ(CRL.unionWith(GetCRL({{APN4, APN2}})),
+            GetCRL({{APN4, APN2}, {AP0, AP4}, {AP8, AP12}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP6, AP7}})),
+            GetCRL({{AP0, AP4}, {AP6, AP7}, {AP8, AP12}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP16, AP18}})),
+            GetCRL({{AP0, AP4}, {AP8, AP12}, {AP16, AP18}}));
+
+  EXPECT_EQ(CRL.unionWith(GetCRL({{APN2, AP2}})),
+            GetCRL({{APN2, AP4}, {AP8, AP12}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP2, AP6}})),
+            GetCRL({{AP0, AP6}, {AP8, AP12}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP10, AP16}})),
+            GetCRL({{AP0, AP4}, {AP8, AP16}}));
+
+  EXPECT_EQ(CRL.unionWith(GetCRL({{APN2, AP10}})), GetCRL({{APN2, AP12}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP2, AP10}})), GetCRL({{AP0, AP12}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{AP4, AP16}})), GetCRL({{AP0, AP16}}));
+  EXPECT_EQ(CRL.unionWith(GetCRL({{APN2, AP16}})), GetCRL({{APN2, AP16}}));
+}
+
+TEST_F(ConstantRangeListTest, Intersect) {
+  APInt APN2 = APInt(64, -2, /*isSigned=*/true);
+  APInt AP0 = APInt(64, 0, /*isSigned=*/true);
+  APInt AP2 = APInt(64, 2, /*isSigned=*/true);
+  APInt AP4 = APInt(64, 4, /*isSigned=*/true);
+  APInt AP6 = APInt(64, 6, /*isSigned=*/true);
+  APInt AP7 = APInt(64, 7, /*isSigned=*/true);
+  APInt AP8 = APInt(64, 8, /*isSigned=*/true);
+  APInt AP10 = APInt(64, 10, /*isSigned=*/true);
+  APInt AP11 = APInt(64, 11, /*isSigned=*/true);
+  APInt AP12 = APInt(64, 12, /*isSigned=*/true);
+  APInt AP16 = APInt(64, 16, /*isSigned=*/true);
+  ConstantRangeList CRL = GetCRL({{AP0, AP4}, {AP8, AP12}});
+
+  // No intersection.
+  ConstantRangeList Empty;
+  EXPECT_EQ(CRL.intersectWith(Empty), Empty);
+  EXPECT_EQ(Empty.intersectWith(CRL), Empty);
+
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP0}})), Empty);
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP6, AP8}})), Empty);
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP12, AP16}})), Empty);
+
+  // Single intersect range.
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP2}})), GetCRL({{AP0, AP2}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP6}})), GetCRL({{AP0, AP4}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP2, AP4}})), GetCRL({{AP2, AP4}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP2, AP6}})), GetCRL({{AP2, AP4}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP6, AP10}})), GetCRL({{AP8, AP10}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP6, AP16}})), GetCRL({{AP8, AP12}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP10, AP12}})), GetCRL({{AP10, AP12}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP10, AP16}})), GetCRL({{AP10, AP12}}));
+
+  // Multiple intersect ranges.
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP10}})),
+            GetCRL({{AP0, AP4}, {AP8, AP10}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP16}})), CRL);
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP2, AP10}})),
+            GetCRL({{AP2, AP4}, {AP8, AP10}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP2, AP16}})),
+            GetCRL({{AP2, AP4}, {AP8, AP12}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP2}, {AP6, AP10}})),
+            GetCRL({{AP0, AP2}, {AP8, AP10}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{AP2, AP6}, {AP10, AP16}})),
+            GetCRL({{AP2, AP4}, {AP10, AP12}}));
+  EXPECT_EQ(CRL.intersectWith(GetCRL({{APN2, AP2}, {AP7, AP10}, {AP11, AP16}})),
+            GetCRL({{AP0, AP2}, {AP8, AP10}, {AP11, AP12}}));
+  EXPECT_EQ(CRL.intersectWith(CRL), CRL);
+}
+
 } // anonymous namespace


        


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