fix a off-by-one bug in intersectWith(), and add a bunch of tests

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159319 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index e7d848312809318c39cd849bd67b3b7ed8453005..61d333f24a0f092081d7707e3b7fc888c36ede8c 100644 (file)
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -316,7 +316,7 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
 
     return CR;
   }
-  if (CR.Upper.ult(Lower)) {
+  if (CR.Upper.ule(Lower)) {
     if (CR.Lower.ult(Lower))
       return *this;
 

diff --git a/unittests/Support/ConstantRangeTest.cpp b/unittests/Support/ConstantRangeTest.cpp
index 5fcdcfd2b4c6200f4f3f03012ad6cae585a96f6f..a562080981ae8141053624175450d99f8fd408ce 100644 (file)
--- a/unittests/Support/ConstantRangeTest.cpp
+++ b/unittests/Support/ConstantRangeTest.cpp
@@ -234,9 +234,39 @@ TEST_F(ConstantRangeTest, IntersectWith) {
   EXPECT_TRUE(LHS.intersectWith(RHS) == LHS);
 
   // previous bug: intersection of [min, 3) and [2, max) should be 2
-  LHS = ConstantRange(APInt(32, -2147483648), APInt(32, 3));
-  RHS = ConstantRange(APInt(32, 2), APInt(32, 2147483648));
+  LHS = ConstantRange(APInt(32, -2147483646), APInt(32, 3));
+  RHS = ConstantRange(APInt(32, 2), APInt(32, 2147483646));
   EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 2)));
+
+  // [2, 0) /\ [4, 3) = [2, 0)
+  LHS = ConstantRange(APInt(32, 2), APInt(32, 0));
+  RHS = ConstantRange(APInt(32, 4), APInt(32, 3));
+  EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 2), APInt(32, 0)));
+
+  // [2, 0) /\ [4, 2) = [4, 0)
+  LHS = ConstantRange(APInt(32, 2), APInt(32, 0));
+  RHS = ConstantRange(APInt(32, 4), APInt(32, 2));
+  EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 4), APInt(32, 0)));
+
+  // [4, 2) /\ [5, 1) = [5, 1)
+  LHS = ConstantRange(APInt(32, 4), APInt(32, 2));
+  RHS = ConstantRange(APInt(32, 5), APInt(32, 1));
+  EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 5), APInt(32, 1)));
+
+  // [2, 0) /\ [7, 4) = [7, 4)
+  LHS = ConstantRange(APInt(32, 2), APInt(32, 0));
+  RHS = ConstantRange(APInt(32, 7), APInt(32, 4));
+  EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 7), APInt(32, 4)));
+
+  // [4, 2) /\ [1, 0) = [1, 0)
+  LHS = ConstantRange(APInt(32, 4), APInt(32, 2));
+  RHS = ConstantRange(APInt(32, 1), APInt(32, 0));
+  EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 4), APInt(32, 2)));
+ 
+  // [15, 0) /\ [7, 6) = [15, 0)
+  LHS = ConstantRange(APInt(32, 15), APInt(32, 0));
+  RHS = ConstantRange(APInt(32, 7), APInt(32, 6));
+  EXPECT_EQ(LHS.intersectWith(RHS), ConstantRange(APInt(32, 15), APInt(32, 0)));
 }
 
 TEST_F(ConstantRangeTest, UnionWith) {