1 files changed, 155 insertions, 0 deletions
diff --git a/llvm/utils/TableGen/SubtargetFeatureInfo.cpp b/llvm/utils/TableGen/SubtargetFeatureInfo.cpp
new file mode 100644
index 000000000000..5430f73d5e09
--- /dev/null
+++ b/llvm/utils/TableGen/SubtargetFeatureInfo.cpp
@@ -0,0 +1,155 @@
+//===- SubtargetFeatureInfo.cpp - Helpers for subtarget features ----------===//
+//
+// 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 "SubtargetFeatureInfo.h"
+
+#include "Types.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/TableGen/Record.h"
+
+#include <map>
+
+using namespace llvm;
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD void SubtargetFeatureInfo::dump() const {
+  errs() << getEnumName() << " " << Index << "\n" << *TheDef;
+}
+#endif
+
+std::vector<std::pair<Record *, SubtargetFeatureInfo>>
+SubtargetFeatureInfo::getAll(const RecordKeeper &Records) {
+  std::vector<std::pair<Record *, SubtargetFeatureInfo>> SubtargetFeatures;
+  std::vector<Record *> AllPredicates =
+      Records.getAllDerivedDefinitions("Predicate");
+  for (Record *Pred : AllPredicates) {
+    // Ignore predicates that are not intended for the assembler.
+    //
+    // The "AssemblerMatcherPredicate" string should be promoted to an argument
+    // if we re-use the machinery for non-assembler purposes in future.
+    if (!Pred->getValueAsBit("AssemblerMatcherPredicate"))
+      continue;
+
+    if (Pred->getName().empty())
+      PrintFatalError(Pred->getLoc(), "Predicate has no name!");
+
+    // Ignore always true predicates.
+    if (Pred->getValueAsString("CondString").empty())
+      continue;
+
+    SubtargetFeatures.emplace_back(
+        Pred, SubtargetFeatureInfo(Pred, SubtargetFeatures.size()));
+  }
+  return SubtargetFeatures;
+}
+
+void SubtargetFeatureInfo::emitSubtargetFeatureBitEnumeration(
+    SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) {
+  OS << "// Bits for subtarget features that participate in "
+     << "instruction matching.\n";
+  OS << "enum SubtargetFeatureBits : "
+     << getMinimalTypeForRange(SubtargetFeatures.size()) << " {\n";
+  for (const auto &SF : SubtargetFeatures) {
+    const SubtargetFeatureInfo &SFI = SF.second;
+    OS << "  " << SFI.getEnumBitName() << " = " << SFI.Index << ",\n";
+  }
+  OS << "};\n\n";
+}
+
+void SubtargetFeatureInfo::emitNameTable(
+    SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) {
+  // Need to sort the name table so that lookup by the log of the enum value
+  // gives the proper name. More specifically, for a feature of value 1<<n,
+  // SubtargetFeatureNames[n] should be the name of the feature.
+  uint64_t IndexUB = 0;
+  for (const auto &SF : SubtargetFeatures)
+    if (IndexUB <= SF.second.Index)
+      IndexUB = SF.second.Index+1;
+
+  std::vector<std::string> Names;
+  if (IndexUB > 0)
+    Names.resize(IndexUB);
+  for (const auto &SF : SubtargetFeatures)
+    Names[SF.second.Index] = SF.second.getEnumName();
+
+  OS << "static const char *SubtargetFeatureNames[] = {\n";
+  for (uint64_t I = 0; I < IndexUB; ++I)
+    OS << "  \"" << Names[I] << "\",\n";
+
+  // A small number of targets have no predicates. Null terminate the array to
+  // avoid a zero-length array.
+  OS << "  nullptr\n"
+     << "};\n\n";
+}
+
+void SubtargetFeatureInfo::emitComputeAvailableFeatures(
+    StringRef TargetName, StringRef ClassName, StringRef FuncName,
+    SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS,
+    StringRef ExtraParams) {
+  OS << "PredicateBitset " << TargetName << ClassName << "::\n"
+     << FuncName << "(const " << TargetName << "Subtarget *Subtarget";
+  if (!ExtraParams.empty())
+    OS << ", " << ExtraParams;
+  OS << ") const {\n";
+  OS << "  PredicateBitset Features;\n";
+  for (const auto &SF : SubtargetFeatures) {
+    const SubtargetFeatureInfo &SFI = SF.second;
+    StringRef CondStr = SFI.TheDef->getValueAsString("CondString");
+    assert(!CondStr.empty() && "true predicate should have been filtered");
+
+    OS << "  if (" << CondStr << ")\n";
+    OS << "    Features.set(" << SFI.getEnumBitName() << ");\n";
+  }
+  OS << "  return Features;\n";
+  OS << "}\n\n";
+}
+
+void SubtargetFeatureInfo::emitComputeAssemblerAvailableFeatures(
+    StringRef TargetName, StringRef ClassName, StringRef FuncName,
+    SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) {
+  OS << "FeatureBitset " << TargetName << ClassName << "::\n"
+     << FuncName << "(const FeatureBitset& FB) const {\n";
+  OS << "  FeatureBitset Features;\n";
+  for (const auto &SF : SubtargetFeatures) {
+    const SubtargetFeatureInfo &SFI = SF.second;
+
+    OS << "  if (";
+    std::string CondStorage =
+        SFI.TheDef->getValueAsString("AssemblerCondString");
+    StringRef Conds = CondStorage;
+    std::pair<StringRef, StringRef> Comma = Conds.split(',');
+    bool First = true;
+    do {
+      if (!First)
+        OS << " && ";
+
+      bool Neg = false;
+      StringRef Cond = Comma.first;
+      if (Cond[0] == '!') {
+        Neg = true;
+        Cond = Cond.substr(1);
+      }
+
+      OS << "(";
+      if (Neg)
+        OS << "!";
+      OS << "FB[" << TargetName << "::" << Cond << "])";
+
+      if (Comma.second.empty())
+        break;
+
+      First = false;
+      Comma = Comma.second.split(',');
+    } while (true);
+
+    OS << ")\n";
+    OS << "    Features.set(" << SFI.getEnumBitName() << ");\n";
+  }
+  OS << "  return Features;\n";
+  OS << "}\n\n";
+}