[PowerPC][llvm-exegesis] Add a PowerPC target

[jsji]

Summary

This is patch to add PowerPC target to llvm-exegesis.
The target does just enough to be able to run llvm-exegesis in latency mode for at least some opcodes.

[courbet]

Thanks for the patch !

llvm/tools/llvm-exegesis/lib/CMakeLists.txt

13

I think you wrote this against the version before PR39021 and failed to merge the changes in r342865.

llvm/tools/llvm-exegesis/lib/PowerPC/Target.cpp

9

"The PowerPC ExegesisTarget."

33

remove the namespace; LLVM style does not put static functions in anonymous namespaces.

34

getLoadImmediateOpcode

llvm/unittests/tools/llvm-exegesis/PowerPC/AnalysisTest.cpp

2

This file is missing a header.

llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp

2

ditto

[gchatelet]

Nice ! Thx for the patch !

llvm/unittests/tools/llvm-exegesis/PowerPC/AnalysisTest.cpp

32

typo unes

[jsji]

Thanks for prompt review, I will update the patch to fix the issues.

llvm/tools/llvm-exegesis/lib/CMakeLists.txt

13

Yes, you are right! I did a quick update before submitting the patch, and apparently I didn't merge all changes correctly. I will have a look at r342865, and update the patch. Thanks.

llvm/tools/llvm-exegesis/lib/PowerPC/Target.cpp

9

OK

33

OK

34

OK

llvm/unittests/tools/llvm-exegesis/PowerPC/AnalysisTest.cpp

2

I'll have a look, Thanks.

[jsji]

Addressed the review comments.

[jedilyn]

llvm/tools/llvm-exegesis/lib/PowerPC/Target.cpp

32

It seems these two static functions are still put in anonymous namespace (line 18 - line 76).

[courbet]

Please address the last comment by jedilyn@.

[jsji]

Address anonymous namespace/static comment.

llvm/tools/llvm-exegesis/lib/CMakeLists.txt

 set(TARGETS_TO_APPEND "")
 
 if (LLVM_TARGETS_TO_BUILD MATCHES "X86")
   add_subdirectory(X86)
   set(TARGETS_TO_APPEND "${TARGETS_TO_APPEND} X86")
 endif()
 if (LLVM_TARGETS_TO_BUILD MATCHES "AArch64")
   add_subdirectory(AArch64)
   set(TARGETS_TO_APPEND "${TARGETS_TO_APPEND} AArch64")
 endif()
+if (LLVM_TARGETS_TO_BUILD MATCHES "PowerPC")
+  add_subdirectory(PowerPC)
+  set(TARGETS_TO_APPEND "${TARGETS_TO_APPEND} PowerPC")
+endif()
 
 set(LLVM_EXEGESIS_TARGETS "${LLVM_EXEGESIS_TARGETS} ${TARGETS_TO_APPEND}" PARENT_SCOPE)
 
 add_library(LLVMExegesis
   STATIC
   Analysis.cpp
   Assembler.cpp
   BenchmarkResult.cpp

llvm/tools/llvm-exegesis/lib/PowerPC/CMakeLists.txt

+include_directories(
+  ${LLVM_MAIN_SRC_DIR}/lib/Target/PowerPC
+  ${LLVM_BINARY_DIR}/lib/Target/PowerPC
+  )
+
+add_library(LLVMExegesisPowerPC
+  STATIC
+  Target.cpp
+  )
+
+llvm_update_compile_flags(LLVMExegesisPowerPC)
+llvm_map_components_to_libnames(libs
+  PowerPC
+  Exegesis
+  )
+
+target_link_libraries(LLVMExegesisPowerPC ${libs})
+set_target_properties(LLVMExegesisPowerPC PROPERTIES FOLDER "Libraries")

llvm/tools/llvm-exegesis/lib/PowerPC/LLVMBuild.txt

+;===- ./tools/llvm-exegesis/lib/PowerPC/LLVMBuild.txt ---------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = ExegesisPowerPC
+parent = Libraries
+required_libraries = PowerPC

llvm/tools/llvm-exegesis/lib/PowerPC/Target.cpp

+//===-- Target.cpp ----------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+// The PowerPC ExegesisTarget.
+//===----------------------------------------------------------------------===//
+#include "../Target.h"
+#include "../Latency.h"
+#include "PPC.h"
+#include "PPCRegisterInfo.h"
+
+namespace llvm {
+namespace exegesis {
+
+namespace {
+
+class PowerPCLatencyBenchmarkRunner : public LatencyBenchmarkRunner {
+public:
+  PowerPCLatencyBenchmarkRunner(const LLVMState &State)
+      : LatencyBenchmarkRunner(State) {}
+
+private:
+  const char *getCounterName() const override {
+    // All PowerPC subtargets have CYCLES as the cycle counter name
+    return "CYCLES";
+  }
+};
+
+static unsigned getLoadImmediateOpcode(unsigned RegBitWidth) {
+  switch (RegBitWidth) {
+  case 32:
+    return llvm::PPC::LI;
+  case 64:
+    return llvm::PPC::LI8;
+  }
+  llvm_unreachable("Invalid Value Width");
+}
+
+// Generates instruction to load an immediate value into a register.
+static llvm::MCInst loadImmediate(unsigned Reg, unsigned RegBitWidth,
+                                  const llvm::APInt &Value) {
+  if (Value.getBitWidth() > RegBitWidth)
+    llvm_unreachable("Value must fit in the Register");
+  return llvm::MCInstBuilder(getLoadImmediateOpcode(RegBitWidth))
+      .addReg(Reg)
+      .addImm(Value.getZExtValue());
+}
+
+class ExegesisPowerPCTarget : public ExegesisTarget {
+public:
+  ExegesisPowerPCTarget() : ExegesisTarget({}) {}
+
+private:
+  std::vector<llvm::MCInst> setRegTo(const llvm::MCSubtargetInfo &STI,
+                                     unsigned Reg,
+                                     const llvm::APInt &Value) const override {
+    if (llvm::PPC::GPRCRegClass.contains(Reg))
+      return {loadImmediate(Reg, 32, Value)};
+    if (llvm::PPC::G8RCRegClass.contains(Reg))
+      return {loadImmediate(Reg, 64, Value)};
+    llvm::errs() << "setRegTo is not implemented, results will be unreliable\n";
+    return {};
+  }
+  bool matchesArch(llvm::Triple::ArchType Arch) const override {
+    return Arch == llvm::Triple::ppc64le;
+  }
+  std::unique_ptr<BenchmarkRunner>
+  createLatencyBenchmarkRunner(const LLVMState &State) const override {
+    return llvm::make_unique<PowerPCLatencyBenchmarkRunner>(State);
+  }
+};
+
+} // namespace
+
+static ExegesisTarget *getTheExegesisPowerPCTarget() {
+  static ExegesisPowerPCTarget Target;
+  return &Target;
+}
+
+void InitializePowerPCExegesisTarget() {
+  ExegesisTarget::registerTarget(getTheExegesisPowerPCTarget());
+}
+
+} // namespace exegesis
+} // namespace llvm

llvm/unittests/tools/llvm-exegesis/CMakeLists.txt

if(LLVM_TARGETS_TO_BUILD MATCHES "X86")
   add_subdirectory(X86)
 endif()
 if(LLVM_TARGETS_TO_BUILD MATCHES "ARM")
   add_subdirectory(ARM)
 endif()
 if(LLVM_TARGETS_TO_BUILD MATCHES "AArch64")
   add_subdirectory(AArch64)
 endif()
+if(LLVM_TARGETS_TO_BUILD MATCHES "PowerPC")
+  add_subdirectory(PowerPC)
+endif()

llvm/unittests/tools/llvm-exegesis/PowerPC/AnalysisTest.cpp

+//===-- AnalysisTest.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Analysis.h"
+
+#include <cassert>
+#include <memory>
+
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace llvm{
+namespace exegesis {
+namespace {
+
+using testing::Pair;
+using testing::UnorderedElementsAre;
+
+class AnalysisTest : public ::testing::Test {
+protected:
+  AnalysisTest() {
+    const std::string TT = "powerpc64le-unknown-linux";
+    std::string error;
+    const llvm::Target *const TheTarget =
+        llvm::TargetRegistry::lookupTarget(TT, error);
+    if (!TheTarget) {
+      llvm::errs() << error << "\n";
+      return;
+    }
+    STI.reset(TheTarget->createMCSubtargetInfo(TT, "pwr9", ""));
+
+    // Compute the ProxResIdx of ports uses in tests.
+    const auto &SM = STI->getSchedModel();
+    for (unsigned I = 0, E = SM.getNumProcResourceKinds(); I < E; ++I) {
+      const std::string Name = SM.getProcResource(I)->Name;
+      if (Name == "ALU") {
+        ALUIdx = I;
+      } else if (Name == "ALUE") {
+        ALUEIdx = I;
+      } else if (Name == "ALUO") {
+        ALUOIdx = I;
+      } else if (Name == "IP_AGEN") {
+        IPAGENIdx = I;
+      }
+    }
+    EXPECT_NE(ALUIdx, 0);
+    EXPECT_NE(ALUEIdx, 0);
+    EXPECT_NE(ALUOIdx, 0);
+    EXPECT_NE(IPAGENIdx, 0);
+  }
+
+  static void SetUpTestCase() {
+    LLVMInitializePowerPCTargetInfo();
+    LLVMInitializePowerPCTarget();
+    LLVMInitializePowerPCTargetMC();
+  }
+
+protected:
+  std::unique_ptr<const llvm::MCSubtargetInfo> STI;
+  uint16_t ALUIdx = 0;
+  uint16_t ALUEIdx = 0;
+  uint16_t ALUOIdx = 0;
+  uint16_t IPAGENIdx = 0;
+};
+
+TEST_F(AnalysisTest, ComputeIdealizedProcResPressure_2ALU) {
+  const auto Pressure =
+      computeIdealizedProcResPressure(STI->getSchedModel(), {{ALUIdx, 2}});
+  EXPECT_THAT(Pressure, UnorderedElementsAre(Pair(ALUIdx, 2.0)));
+}
+
+TEST_F(AnalysisTest, ComputeIdealizedProcResPressure_1ALUE) {
+  const auto Pressure =
+      computeIdealizedProcResPressure(STI->getSchedModel(), {{ALUEIdx, 2}});
+  EXPECT_THAT(Pressure, UnorderedElementsAre(Pair(ALUEIdx, 2.0)));
+}
+
+TEST_F(AnalysisTest, ComputeIdealizedProcResPressure_1ALU1IPAGEN) {
+  const auto Pressure =
+      computeIdealizedProcResPressure(STI->getSchedModel(), {{ALUIdx, 1}, {IPAGENIdx, 1}});
+  EXPECT_THAT(Pressure, UnorderedElementsAre(Pair(ALUIdx, 1.0),Pair(IPAGENIdx, 1)));
+}
+} // namespace
+} // namespace exegesis
+} // namespace llvm

llvm/unittests/tools/llvm-exegesis/PowerPC/CMakeLists.txt

+include_directories(
+  ${LLVM_MAIN_SRC_DIR}/lib/Target/PowerPC
+  ${LLVM_BINARY_DIR}/lib/Target/PowerPC
+  ${LLVM_MAIN_SRC_DIR}/tools/llvm-exegesis/lib
+  )
+
+set(LLVM_LINK_COMPONENTS
+  MC
+  MCParser
+  Object
+  Support
+  Symbolize
+  PowerPC
+  )
+
+add_llvm_unittest(LLVMExegesisPowerPCTests
+  AnalysisTest.cpp
+  TargetTest.cpp
+  )
+target_link_libraries(LLVMExegesisPowerPCTests PRIVATE
+  LLVMExegesis
+  LLVMExegesisPowerPC)

llvm/unittests/tools/llvm-exegesis/PowerPC/TargetTest.cpp

+//===-- TargetTest.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Target.h"
+
+#include <cassert>
+#include <memory>
+
+#include "MCTargetDesc/PPCMCTargetDesc.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace llvm{
+namespace exegesis {
+
+void InitializePowerPCExegesisTarget();
+
+namespace {
+
+using testing::NotNull;
+using testing::IsEmpty;
+using testing::Not;
+
+constexpr const char kTriple[] = "powerpc64le-unknown-linux";
+
+class PowerPCTargetTest : public ::testing::Test {
+protected:
+  PowerPCTargetTest()
+      : ExegesisTarget_(ExegesisTarget::lookup(llvm::Triple(kTriple))) {
+    EXPECT_THAT(ExegesisTarget_, NotNull());
+    std::string error;
+    Target_ = llvm::TargetRegistry::lookupTarget(kTriple, error);
+    EXPECT_THAT(Target_, NotNull());
+  }
+  static void SetUpTestCase() {
+    LLVMInitializePowerPCTargetInfo();
+    LLVMInitializePowerPCTarget();
+    LLVMInitializePowerPCTargetMC();
+    InitializePowerPCExegesisTarget();
+  }
+
+  const llvm::Target *Target_;
+  const ExegesisTarget *const ExegesisTarget_;
+};
+
+TEST_F(PowerPCTargetTest, SetRegToConstant) {
+  const std::unique_ptr<llvm::MCSubtargetInfo> STI(
+      Target_->createMCSubtargetInfo(kTriple, "generic", ""));
+  const auto Insts =
+      ExegesisTarget_->setRegTo(*STI, llvm::PPC::X0, llvm::APInt());
+  EXPECT_THAT(Insts, Not(IsEmpty()));
+}
+
+} // namespace
+} // namespace exegesis
+} // namespace llvm