[VPlan] Add initial VPDT test. (NFC)

llvm/unittests/Transforms/Vectorize/CMakeLists.txt

@@ -8,6 +8,7 @@ set(LLVM_LINK_COMPONENTS
 
 add_llvm_unittest(VectorizeTests
   VPlanTest.cpp
+  VPDomTreeTest.cpp
   VPlanHCFGTest.cpp
   VPlanSlpTest.cpp
   )

llvm/unittests/Transforms/Vectorize/VPDomTreeTest.cpp

@@ -0,0 +1,57 @@
+//===- llvm/unittests/Transforms/Vectorize/VPDomTreeTests.cpp - -----------===//
+//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "../lib/Transforms/Vectorize/VPlan.h"
+#include "../lib/Transforms/Vectorize/VPlanDominatorTree.h"
+#include "gtest/gtest.h"
+
+namespace llvm {
+namespace {
+
+TEST(VPDominatorTreeTest, DominanceNoRegionsTest) {
+  //   R1 {
+  //     VPBB1
+  //     /   \
+    // VPBB2  VPBB3
+  //    \    /
+  //    VPBB4
+  //  }
+  VPBasicBlock *VPBB1 = new VPBasicBlock("VPBB1");
+  VPBasicBlock *VPBB2 = new VPBasicBlock("VPBB2");
+  VPBasicBlock *VPBB3 = new VPBasicBlock("VPBB3");
+  VPBasicBlock *VPBB4 = new VPBasicBlock("VPBB4");
+  VPRegionBlock *R1 = new VPRegionBlock(VPBB1, VPBB4);
+  VPBB2->setParent(R1);
+  VPBB3->setParent(R1);
+
+  VPBlockUtils::connectBlocks(VPBB1, VPBB2);
+  VPBlockUtils::connectBlocks(VPBB1, VPBB3);
+  VPBlockUtils::connectBlocks(VPBB2, VPBB4);
+  VPBlockUtils::connectBlocks(VPBB3, VPBB4);
+
+  VPlan Plan;
+  Plan.setEntry(R1);
+  VPDominatorTree VPDT;
+  VPDT.recalculate(*R1);
+
+  EXPECT_TRUE(VPDT.dominates(VPBB1, VPBB4));
+  EXPECT_FALSE(VPDT.dominates(VPBB4, VPBB1));
+
+  EXPECT_TRUE(VPDT.dominates(VPBB1, VPBB2));
+  EXPECT_FALSE(VPDT.dominates(VPBB2, VPBB1));
+
+  EXPECT_TRUE(VPDT.dominates(VPBB1, VPBB3));
+  EXPECT_FALSE(VPDT.dominates(VPBB3, VPBB1));
+
+  EXPECT_EQ(VPDT.findNearestCommonDominator(VPBB2, VPBB3), VPBB1);
+  EXPECT_EQ(VPDT.findNearestCommonDominator(VPBB2, VPBB4), VPBB1);
+  EXPECT_EQ(VPDT.findNearestCommonDominator(VPBB4, VPBB4), VPBB4);
+}
+} // namespace
+} // namespace llvm