1 files changed, 87 insertions, 0 deletions
diff --git a/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp b/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp
new file mode 100644
index 00000000000..c6bbd8b1cf5
--- /dev/null
+++ b/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp
@@ -0,0 +1,87 @@
+//===- CSETest.cpp -----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "GISelMITest.h"
+#include "llvm/CodeGen/GlobalISel/CSEMIRBuilder.h"
+
+namespace {
+
+TEST_F(GISelMITest, TestCSE) {
+  if (!TM)
+    return;
+
+  LLT s16{LLT::scalar(16)};
+  LLT s32{LLT::scalar(32)};
+  auto MIBInput = B.buildInstr(TargetOpcode::G_TRUNC, {s16}, {Copies[0]});
+  auto MIBInput1 = B.buildInstr(TargetOpcode::G_TRUNC, {s16}, {Copies[1]});
+  auto MIBAdd = B.buildInstr(TargetOpcode::G_ADD, {s16}, {MIBInput, MIBInput});
+  GISelCSEInfo CSEInfo;
+  CSEInfo.setCSEConfig(make_unique<CSEConfig>());
+  CSEInfo.analyze(*MF);
+  B.setCSEInfo(&CSEInfo);
+  CSEMIRBuilder CSEB(B.getState());
+  CSEB.setInsertPt(*EntryMBB, EntryMBB->begin());
+  unsigned AddReg = MRI->createGenericVirtualRegister(s16);
+  auto MIBAddCopy =
+      CSEB.buildInstr(TargetOpcode::G_ADD, {AddReg}, {MIBInput, MIBInput});
+  ASSERT_EQ(MIBAddCopy->getOpcode(), TargetOpcode::COPY);
+  auto MIBAdd2 =
+      CSEB.buildInstr(TargetOpcode::G_ADD, {s16}, {MIBInput, MIBInput});
+  ASSERT_TRUE(&*MIBAdd == &*MIBAdd2);
+  auto MIBAdd4 =
+      CSEB.buildInstr(TargetOpcode::G_ADD, {s16}, {MIBInput, MIBInput});
+  ASSERT_TRUE(&*MIBAdd == &*MIBAdd4);
+  auto MIBAdd5 =
+      CSEB.buildInstr(TargetOpcode::G_ADD, {s16}, {MIBInput, MIBInput1});
+  ASSERT_TRUE(&*MIBAdd != &*MIBAdd5);
+
+  // Try building G_CONSTANTS.
+  auto MIBCst = CSEB.buildConstant(s32, 0);
+  auto MIBCst1 = CSEB.buildConstant(s32, 0);
+  ASSERT_TRUE(&*MIBCst == &*MIBCst1);
+  // Try the CFing of BinaryOps.
+  auto MIBCF1 = CSEB.buildInstr(TargetOpcode::G_ADD, {s32}, {MIBCst, MIBCst});
+  ASSERT_TRUE(&*MIBCF1 == &*MIBCst);
+
+  // Try out building FCONSTANTs.
+  auto MIBFP0 = CSEB.buildFConstant(s32, 1.0);
+  auto MIBFP0_1 = CSEB.buildFConstant(s32, 1.0);
+  ASSERT_TRUE(&*MIBFP0 == &*MIBFP0_1);
+  CSEInfo.print();
+
+  // Check G_UNMERGE_VALUES
+  auto MIBUnmerge = CSEB.buildUnmerge({s32, s32}, Copies[0]);
+  auto MIBUnmerge2 = CSEB.buildUnmerge({s32, s32}, Copies[0]);
+  ASSERT_TRUE(&*MIBUnmerge == &*MIBUnmerge2);
+}
+
+TEST_F(GISelMITest, TestCSEConstantConfig) {
+  if (!TM)
+    return;
+
+  LLT s16{LLT::scalar(16)};
+  auto MIBInput = B.buildInstr(TargetOpcode::G_TRUNC, {s16}, {Copies[0]});
+  auto MIBAdd = B.buildInstr(TargetOpcode::G_ADD, {s16}, {MIBInput, MIBInput});
+  auto MIBZero = B.buildConstant(s16, 0);
+  GISelCSEInfo CSEInfo;
+  CSEInfo.setCSEConfig(make_unique<CSEConfigConstantOnly>());
+  CSEInfo.analyze(*MF);
+  B.setCSEInfo(&CSEInfo);
+  CSEMIRBuilder CSEB(B.getState());
+  CSEB.setInsertPt(*EntryMBB, EntryMBB->begin());
+  auto MIBAdd1 =
+      CSEB.buildInstr(TargetOpcode::G_ADD, {s16}, {MIBInput, MIBInput});
+  // We should CSE constants only. Adds should not be CSEd.
+  ASSERT_TRUE(MIBAdd1->getOpcode() != TargetOpcode::COPY);
+  ASSERT_TRUE(&*MIBAdd1 != &*MIBAdd);
+  // We should CSE constant.
+  auto MIBZeroTmp = CSEB.buildConstant(s16, 0);
+  ASSERT_TRUE(&*MIBZero == &*MIBZeroTmp);
+}
+} // namespace