Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp

@@ -0,0 +1,457 @@
+//===-- PPCTargetMachine.cpp - Define TargetMachine for PowerPC -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Top-level implementation for the PowerPC target.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPCTargetMachine.h"
+#include "MCTargetDesc/PPCMCTargetDesc.h"
+#include "PPC.h"
+#include "PPCSubtarget.h"
+#include "PPCTargetObjectFile.h"
+#include "PPCTargetTransformInfo.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/TargetLoweringObjectFile.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/CodeGen.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cassert>
+#include <memory>
+#include <string>
+
+using namespace llvm;
+
+
+static cl::opt<bool>
+    EnableBranchCoalescing("enable-ppc-branch-coalesce", cl::Hidden,
+                           cl::desc("enable coalescing of duplicate branches for PPC"));
+static cl::
+opt<bool> DisableCTRLoops("disable-ppc-ctrloops", cl::Hidden,
+                        cl::desc("Disable CTR loops for PPC"));
+
+static cl::
+opt<bool> DisablePreIncPrep("disable-ppc-preinc-prep", cl::Hidden,
+                            cl::desc("Disable PPC loop preinc prep"));
+
+static cl::opt<bool>
+VSXFMAMutateEarly("schedule-ppc-vsx-fma-mutation-early",
+  cl::Hidden, cl::desc("Schedule VSX FMA instruction mutation early"));
+
+static cl::
+opt<bool> DisableVSXSwapRemoval("disable-ppc-vsx-swap-removal", cl::Hidden,
+                                cl::desc("Disable VSX Swap Removal for PPC"));
+
+static cl::
+opt<bool> DisableQPXLoadSplat("disable-ppc-qpx-load-splat", cl::Hidden,
+                              cl::desc("Disable QPX load splat simplification"));
+
+static cl::
+opt<bool> DisableMIPeephole("disable-ppc-peephole", cl::Hidden,
+                            cl::desc("Disable machine peepholes for PPC"));
+
+static cl::opt<bool>
+EnableGEPOpt("ppc-gep-opt", cl::Hidden,
+             cl::desc("Enable optimizations on complex GEPs"),
+             cl::init(true));
+
+static cl::opt<bool>
+EnablePrefetch("enable-ppc-prefetching",
+                  cl::desc("disable software prefetching on PPC"),
+                  cl::init(false), cl::Hidden);
+
+static cl::opt<bool>
+EnableExtraTOCRegDeps("enable-ppc-extra-toc-reg-deps",
+                      cl::desc("Add extra TOC register dependencies"),
+                      cl::init(true), cl::Hidden);
+
+static cl::opt<bool>
+EnableMachineCombinerPass("ppc-machine-combiner",
+                          cl::desc("Enable the machine combiner pass"),
+                          cl::init(true), cl::Hidden);
+
+static cl::opt<bool>
+  ReduceCRLogical("ppc-reduce-cr-logicals",
+                  cl::desc("Expand eligible cr-logical binary ops to branches"),
+                  cl::init(false), cl::Hidden);
+extern "C" void LLVMInitializePowerPCTarget() {
+  // Register the targets
+  RegisterTargetMachine<PPCTargetMachine> A(getThePPC32Target());
+  RegisterTargetMachine<PPCTargetMachine> B(getThePPC64Target());
+  RegisterTargetMachine<PPCTargetMachine> C(getThePPC64LETarget());
+
+  PassRegistry &PR = *PassRegistry::getPassRegistry();
+  initializePPCBoolRetToIntPass(PR);
+  initializePPCExpandISELPass(PR);
+  initializePPCPreEmitPeepholePass(PR);
+  initializePPCTLSDynamicCallPass(PR);
+  initializePPCMIPeepholePass(PR);
+}
+
+/// Return the datalayout string of a subtarget.
+static std::string getDataLayoutString(const Triple &T) {
+  bool is64Bit = T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le;
+  std::string Ret;
+
+  // Most PPC* platforms are big endian, PPC64LE is little endian.
+  if (T.getArch() == Triple::ppc64le)
+    Ret = "e";
+  else
+    Ret = "E";
+
+  Ret += DataLayout::getManglingComponent(T);
+
+  // PPC32 has 32 bit pointers. The PS3 (OS Lv2) is a PPC64 machine with 32 bit
+  // pointers.
+  if (!is64Bit || T.getOS() == Triple::Lv2)
+    Ret += "-p:32:32";
+
+  // Note, the alignment values for f64 and i64 on ppc64 in Darwin
+  // documentation are wrong; these are correct (i.e. "what gcc does").
+  if (is64Bit || !T.isOSDarwin())
+    Ret += "-i64:64";
+  else
+    Ret += "-f64:32:64";
+
+  // PPC64 has 32 and 64 bit registers, PPC32 has only 32 bit ones.
+  if (is64Bit)
+    Ret += "-n32:64";
+  else
+    Ret += "-n32";
+
+  return Ret;
+}
+
+static std::string computeFSAdditions(StringRef FS, CodeGenOpt::Level OL,
+                                      const Triple &TT) {
+  std::string FullFS = FS;
+
+  // Make sure 64-bit features are available when CPUname is generic
+  if (TT.getArch() == Triple::ppc64 || TT.getArch() == Triple::ppc64le) {
+    if (!FullFS.empty())
+      FullFS = "+64bit," + FullFS;
+    else
+      FullFS = "+64bit";
+  }
+
+  if (OL >= CodeGenOpt::Default) {
+    if (!FullFS.empty())
+      FullFS = "+crbits," + FullFS;
+    else
+      FullFS = "+crbits";
+  }
+
+  if (OL != CodeGenOpt::None) {
+    if (!FullFS.empty())
+      FullFS = "+invariant-function-descriptors," + FullFS;
+    else
+      FullFS = "+invariant-function-descriptors";
+  }
+
+  return FullFS;
+}
+
+static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
+  // If it isn't a Mach-O file then it's going to be a linux ELF
+  // object file.
+  if (TT.isOSDarwin())
+    return llvm::make_unique<TargetLoweringObjectFileMachO>();
+
+  return llvm::make_unique<PPC64LinuxTargetObjectFile>();
+}
+
+static PPCTargetMachine::PPCABI computeTargetABI(const Triple &TT,
+                                                 const TargetOptions &Options) {
+  if (Options.MCOptions.getABIName().startswith("elfv1"))
+    return PPCTargetMachine::PPC_ABI_ELFv1;
+  else if (Options.MCOptions.getABIName().startswith("elfv2"))
+    return PPCTargetMachine::PPC_ABI_ELFv2;
+
+  assert(Options.MCOptions.getABIName().empty() &&
+         "Unknown target-abi option!");
+
+  if (TT.isMacOSX())
+    return PPCTargetMachine::PPC_ABI_UNKNOWN;
+
+  switch (TT.getArch()) {
+  case Triple::ppc64le:
+    return PPCTargetMachine::PPC_ABI_ELFv2;
+  case Triple::ppc64:
+    return PPCTargetMachine::PPC_ABI_ELFv1;
+  default:
+    return PPCTargetMachine::PPC_ABI_UNKNOWN;
+  }
+}
+
+static Reloc::Model getEffectiveRelocModel(const Triple &TT,
+                                           Optional<Reloc::Model> RM) {
+  if (RM.hasValue())
+    return *RM;
+
+  // Darwin defaults to dynamic-no-pic.
+  if (TT.isOSDarwin())
+    return Reloc::DynamicNoPIC;
+
+  // Non-darwin 64-bit platforms are PIC by default.
+  if (TT.getArch() == Triple::ppc64 || TT.getArch() == Triple::ppc64le)
+    return Reloc::PIC_;
+
+  // 32-bit is static by default.
+  return Reloc::Static;
+}
+
+static CodeModel::Model getEffectiveCodeModel(const Triple &TT,
+                                              Optional<CodeModel::Model> CM,
+                                              bool JIT) {
+  if (CM)
+    return *CM;
+  if (!TT.isOSDarwin() && !JIT &&
+      (TT.getArch() == Triple::ppc64 || TT.getArch() == Triple::ppc64le))
+    return CodeModel::Medium;
+  return CodeModel::Small;
+}
+
+// The FeatureString here is a little subtle. We are modifying the feature
+// string with what are (currently) non-function specific overrides as it goes
+// into the LLVMTargetMachine constructor and then using the stored value in the
+// Subtarget constructor below it.
+PPCTargetMachine::PPCTargetMachine(const Target &T, const Triple &TT,
+                                   StringRef CPU, StringRef FS,
+                                   const TargetOptions &Options,
+                                   Optional<Reloc::Model> RM,
+                                   Optional<CodeModel::Model> CM,
+                                   CodeGenOpt::Level OL, bool JIT)
+    : LLVMTargetMachine(T, getDataLayoutString(TT), TT, CPU,
+                        computeFSAdditions(FS, OL, TT), Options,
+                        getEffectiveRelocModel(TT, RM),
+                        getEffectiveCodeModel(TT, CM, JIT), OL),
+      TLOF(createTLOF(getTargetTriple())),
+      TargetABI(computeTargetABI(TT, Options)) {
+  initAsmInfo();
+}
+
+PPCTargetMachine::~PPCTargetMachine() = default;
+
+const PPCSubtarget *
+PPCTargetMachine::getSubtargetImpl(const Function &F) const {
+  Attribute CPUAttr = F.getFnAttribute("target-cpu");
+  Attribute FSAttr = F.getFnAttribute("target-features");
+
+  std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
+                        ? CPUAttr.getValueAsString().str()
+                        : TargetCPU;
+  std::string FS = !FSAttr.hasAttribute(Attribute::None)
+                       ? FSAttr.getValueAsString().str()
+                       : TargetFS;
+
+  // FIXME: This is related to the code below to reset the target options,
+  // we need to know whether or not the soft float flag is set on the
+  // function before we can generate a subtarget. We also need to use
+  // it as a key for the subtarget since that can be the only difference
+  // between two functions.
+  bool SoftFloat =
+      F.getFnAttribute("use-soft-float").getValueAsString() == "true";
+  // If the soft float attribute is set on the function turn on the soft float
+  // subtarget feature.
+  if (SoftFloat)
+    FS += FS.empty() ? "-hard-float" : ",-hard-float";
+
+  auto &I = SubtargetMap[CPU + FS];
+  if (!I) {
+    // This needs to be done before we create a new subtarget since any
+    // creation will depend on the TM and the code generation flags on the
+    // function that reside in TargetOptions.
+    resetTargetOptions(F);
+    I = llvm::make_unique<PPCSubtarget>(
+        TargetTriple, CPU,
+        // FIXME: It would be good to have the subtarget additions here
+        // not necessary. Anything that turns them on/off (overrides) ends
+        // up being put at the end of the feature string, but the defaults
+        // shouldn't require adding them. Fixing this means pulling Feature64Bit
+        // out of most of the target cpus in the .td file and making it set only
+        // as part of initialization via the TargetTriple.
+        computeFSAdditions(FS, getOptLevel(), getTargetTriple()), *this);
+  }
+  return I.get();
+}
+
+//===----------------------------------------------------------------------===//
+// Pass Pipeline Configuration
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+/// PPC Code Generator Pass Configuration Options.
+class PPCPassConfig : public TargetPassConfig {
+public:
+  PPCPassConfig(PPCTargetMachine &TM, PassManagerBase &PM)
+    : TargetPassConfig(TM, PM) {}
+
+  PPCTargetMachine &getPPCTargetMachine() const {
+    return getTM<PPCTargetMachine>();
+  }
+
+  void addIRPasses() override;
+  bool addPreISel() override;
+  bool addILPOpts() override;
+  bool addInstSelector() override;
+  void addMachineSSAOptimization() override;
+  void addPreRegAlloc() override;
+  void addPreSched2() override;
+  void addPreEmitPass() override;
+};
+
+} // end anonymous namespace
+
+TargetPassConfig *PPCTargetMachine::createPassConfig(PassManagerBase &PM) {
+  return new PPCPassConfig(*this, PM);
+}
+
+void PPCPassConfig::addIRPasses() {
+  if (TM->getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCBoolRetToIntPass());
+  addPass(createAtomicExpandPass());
+
+  // For the BG/Q (or if explicitly requested), add explicit data prefetch
+  // intrinsics.
+  bool UsePrefetching = TM->getTargetTriple().getVendor() == Triple::BGQ &&
+                        getOptLevel() != CodeGenOpt::None;
+  if (EnablePrefetch.getNumOccurrences() > 0)
+    UsePrefetching = EnablePrefetch;
+  if (UsePrefetching)
+    addPass(createLoopDataPrefetchPass());
+
+  if (TM->getOptLevel() >= CodeGenOpt::Default && EnableGEPOpt) {
+    // Call SeparateConstOffsetFromGEP pass to extract constants within indices
+    // and lower a GEP with multiple indices to either arithmetic operations or
+    // multiple GEPs with single index.
+    addPass(createSeparateConstOffsetFromGEPPass(TM, true));
+    // Call EarlyCSE pass to find and remove subexpressions in the lowered
+    // result.
+    addPass(createEarlyCSEPass());
+    // Do loop invariant code motion in case part of the lowered result is
+    // invariant.
+    addPass(createLICMPass());
+  }
+
+  TargetPassConfig::addIRPasses();
+}
+
+bool PPCPassConfig::addPreISel() {
+  if (!DisablePreIncPrep && getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCLoopPreIncPrepPass(getPPCTargetMachine()));
+
+  if (!DisableCTRLoops && getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCCTRLoops());
+
+  return false;
+}
+
+bool PPCPassConfig::addILPOpts() {
+  addPass(&EarlyIfConverterID);
+
+  if (EnableMachineCombinerPass)
+    addPass(&MachineCombinerID);
+
+  return true;
+}
+
+bool PPCPassConfig::addInstSelector() {
+  // Install an instruction selector.
+  addPass(createPPCISelDag(getPPCTargetMachine(), getOptLevel()));
+
+#ifndef NDEBUG
+  if (!DisableCTRLoops && getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCCTRLoopsVerify());
+#endif
+
+  addPass(createPPCVSXCopyPass());
+  return false;
+}
+
+void PPCPassConfig::addMachineSSAOptimization() {
+  // PPCBranchCoalescingPass need to be done before machine sinking
+  // since it merges empty blocks.
+  if (EnableBranchCoalescing && getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCBranchCoalescingPass());
+  TargetPassConfig::addMachineSSAOptimization();
+  // For little endian, remove where possible the vector swap instructions
+  // introduced at code generation to normalize vector element order.
+  if (TM->getTargetTriple().getArch() == Triple::ppc64le &&
+      !DisableVSXSwapRemoval)
+    addPass(createPPCVSXSwapRemovalPass());
+  // Reduce the number of cr-logical ops.
+  if (ReduceCRLogical && getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCReduceCRLogicalsPass());
+  // Target-specific peephole cleanups performed after instruction
+  // selection.
+  if (!DisableMIPeephole) {
+    addPass(createPPCMIPeepholePass());
+    addPass(&DeadMachineInstructionElimID);
+  }
+}
+
+void PPCPassConfig::addPreRegAlloc() {
+  if (getOptLevel() != CodeGenOpt::None) {
+    initializePPCVSXFMAMutatePass(*PassRegistry::getPassRegistry());
+    insertPass(VSXFMAMutateEarly ? &RegisterCoalescerID : &MachineSchedulerID,
+               &PPCVSXFMAMutateID);
+  }
+
+  // FIXME: We probably don't need to run these for -fPIE.
+  if (getPPCTargetMachine().isPositionIndependent()) {
+    // FIXME: LiveVariables should not be necessary here!
+    // PPCTLSDynamicCallPass uses LiveIntervals which previously dependent on
+    // LiveVariables. This (unnecessary) dependency has been removed now,
+    // however a stage-2 clang build fails without LiveVariables computed here.
+    addPass(&LiveVariablesID, false);
+    addPass(createPPCTLSDynamicCallPass());
+  }
+  if (EnableExtraTOCRegDeps)
+    addPass(createPPCTOCRegDepsPass());
+}
+
+void PPCPassConfig::addPreSched2() {
+  if (getOptLevel() != CodeGenOpt::None) {
+    addPass(&IfConverterID);
+
+    // This optimization must happen after anything that might do store-to-load
+    // forwarding. Here we're after RA (and, thus, when spills are inserted)
+    // but before post-RA scheduling.
+    if (!DisableQPXLoadSplat)
+      addPass(createPPCQPXLoadSplatPass());
+  }
+}
+
+void PPCPassConfig::addPreEmitPass() {
+  addPass(createPPCPreEmitPeepholePass());
+  addPass(createPPCExpandISELPass());
+
+  if (getOptLevel() != CodeGenOpt::None)
+    addPass(createPPCEarlyReturnPass(), false);
+  // Must run branch selection immediately preceding the asm printer.
+  addPass(createPPCBranchSelectionPass(), false);
+}
+
+TargetTransformInfo
+PPCTargetMachine::getTargetTransformInfo(const Function &F) {
+  return TargetTransformInfo(PPCTTIImpl(this, F));
+}