test for empty domain/range and symbols

Author: j2kun

mlir/lib/Analysis/Presburger/IntegerRelation.cpp

@@ -2490,29 +2490,35 @@ IntegerRelation IntegerRelation::rangeProduct(const IntegerRelation &rel) {
 
   // explicit copy of `this`
   IntegerRelation result = *this;
+
+  // An explicit copy of `rel` is needed to merge and align symbols, since that
+  // function mutates both relations.
+  IntegerRelation relCopy = rel;
+  result.mergeAndAlignSymbols(relCopy);
+
   unsigned relRangeVarStart = rel.getVarKindOffset(VarKind::Range);
-  unsigned numRelRangeVars = rel.getNumRangeVars();
   unsigned numThisRangeVars = getNumRangeVars();
+  unsigned numNewSymbolVars = result.getNumSymbolVars() - getNumSymbolVars();
 
-  result.appendVar(VarKind::Range, numRelRangeVars);
+  result.appendVar(VarKind::Range, rel.getNumRangeVars());
 
   // Copy each equality from `rel` and update the copy to account for range
   // variables from `this`. The `rel` equality is a list of coefficients of the
   // variables from `rel`, and so the range variables need to be shifted right
-  // by the number of `this` range variables.
+  // by the number of `this` range variables and symbols.
   for (unsigned i = 0; i < rel.getNumEqualities(); ++i) {
     SmallVector<DynamicAPInt> copy =
         SmallVector<DynamicAPInt>(rel.getEquality(i));
-    copy.insert(copy.begin() + relRangeVarStart, numThisRangeVars,
-                DynamicAPInt(0));
+    copy.insert(copy.begin() + relRangeVarStart,
+                numThisRangeVars + numNewSymbolVars, DynamicAPInt(0));
     result.addEquality(copy);
   }
 
   for (unsigned i = 0; i < rel.getNumInequalities(); ++i) {
     SmallVector<DynamicAPInt> copy =
         SmallVector<DynamicAPInt>(rel.getInequality(i));
-    copy.insert(copy.begin() + relRangeVarStart, numThisRangeVars,
-                DynamicAPInt(0));
+    copy.insert(copy.begin() + relRangeVarStart,
+                numThisRangeVars + numNewSymbolVars, DynamicAPInt(0));
     result.addInequality(copy);
   }
 

mlir/unittests/Analysis/Presburger/IntegerRelationTest.cpp

@@ -653,3 +653,52 @@ TEST(IntegerRelationTest, rangeProductMultdimRangeSwapped) {
 
   EXPECT_TRUE(expected.isEqual(rangeProd));
 }
+
+TEST(IntegerRelationTest, rangeProductEmptyDomain) {
+  IntegerRelation r1 =
+      parseRelationFromSet("(i, j) : (4*i + 9*j == 0, i >= 0, j >= 0)", 0);
+  IntegerRelation r2 =
+      parseRelationFromSet("(k, l) : (2*k + 3*l == 0, k >= 0, l >= 0)", 0);
+  IntegerRelation rangeProd = r1.rangeProduct(r2);
+  IntegerRelation expected =
+      parseRelationFromSet("(i, j, k, l) : (2*k + 3*l == 0, 4*i + 9*j == "
+                           "0, i >= 0, j >= 0, k >= 0, l >= 0)",
+                           0);
+  EXPECT_TRUE(expected.isEqual(rangeProd));
+}
+
+TEST(IntegerRelationTest, rangeProductEmptyRange) {
+  IntegerRelation r1 =
+      parseRelationFromSet("(i, j) : (4*i + 9*j == 0, i >= 0, j >= 0)", 2);
+  IntegerRelation r2 =
+      parseRelationFromSet("(i, j) : (2*i + 3*j == 0, i >= 0, j >= 0)", 2);
+  IntegerRelation rangeProd = r1.rangeProduct(r2);
+  IntegerRelation expected =
+      parseRelationFromSet("(i, j) : (2*i + 3*j == 0, 4*i + 9*j == "
+                           "0, i >= 0, j >= 0)",
+                           2);
+  EXPECT_TRUE(expected.isEqual(rangeProd));
+}
+
+TEST(IntegerRelationTest, rangeProductEmptyDomainAndRange) {
+  IntegerRelation r1 = parseRelationFromSet("() : ()", 0);
+  IntegerRelation r2 = parseRelationFromSet("() : ()", 0);
+  IntegerRelation rangeProd = r1.rangeProduct(r2);
+  IntegerRelation expected = parseRelationFromSet("() : ()", 0);
+  EXPECT_TRUE(expected.isEqual(rangeProd));
+}
+
+TEST(IntegerRelationTest, rangeProductSymbols) {
+  IntegerRelation r1 = parseRelationFromSet(
+      "(i, j)[s] : (2*i + 3*j + s == 0, i >= 0, j >= 0)", 1);
+  IntegerRelation r2 = parseRelationFromSet(
+      "(i, l)[t] : (3*i + 4*l + t == 0, i >= 0, l >= 0)", 1);
+
+  IntegerRelation rangeProd = r1.rangeProduct(r2);
+  IntegerRelation expected = parseRelationFromSet(
+      "(i, j, k, l)[s, t] : (2*i + 3*j + s == 0, 3*i + 4*l + t == "
+      "0, i >= 0, j >= 0, l >= 0)",
+      1);
+
+  EXPECT_TRUE(expected.isEqual(rangeProd));
+}