1 files changed, 38 insertions, 0 deletions
diff --git a/llvm/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp b/llvm/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp
index 6dc7e31e0dab..009dc036cf97 100644
--- a/llvm/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp
+++ b/llvm/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp
@@ -30,10 +30,13 @@ class X86EVEX2VEXTablesEmitter {
   std::map<uint64_t, std::vector<const CodeGenInstruction *>> VEXInsts;
 
   typedef std::pair<const CodeGenInstruction *, const CodeGenInstruction *> Entry;
+  typedef std::pair<StringRef, StringRef> Predicate;
 
   // Represent both compress tables
   std::vector<Entry> EVEX2VEX128;
   std::vector<Entry> EVEX2VEX256;
+  // Represent predicates of VEX instructions.
+  std::vector<Predicate> EVEX2VEXPredicates;
 
 public:
   X86EVEX2VEXTablesEmitter(RecordKeeper &R) : Records(R), Target(R) {}
@@ -45,6 +48,9 @@ private:
   // Prints the given table as a C++ array of type
   // X86EvexToVexCompressTableEntry
   void printTable(const std::vector<Entry> &Table, raw_ostream &OS);
+  // Prints function which checks target feature specific predicate.
+  void printCheckPredicate(const std::vector<Predicate> &Predicates,
+                           raw_ostream &OS);
 };
 
 void X86EVEX2VEXTablesEmitter::printTable(const std::vector<Entry> &Table,
@@ -67,6 +73,19 @@ void X86EVEX2VEXTablesEmitter::printTable(const std::vector<Entry> &Table,
   OS << "};\n\n";
 }
 
+void X86EVEX2VEXTablesEmitter::printCheckPredicate(
+    const std::vector<Predicate> &Predicates, raw_ostream &OS) {
+  OS << "static bool CheckVEXInstPredicate"
+     << "(MachineInstr &MI, const X86Subtarget *Subtarget) {\n"
+     << "  unsigned Opc = MI.getOpcode();\n"
+     << "  switch (Opc) {\n"
+     << "    default: return true;\n";
+  for (auto Pair : Predicates)
+    OS << "    case X86::" << Pair.first << ": return " << Pair.second << ";\n";
+  OS << "  }\n"
+     << "}\n\n";
+}
+
 // Return true if the 2 BitsInits are equal
 // Calculates the integer value residing BitsInit object
 static inline uint64_t getValueFromBitsInit(const BitsInit *B) {
@@ -169,6 +188,18 @@ private:
 };
 
 void X86EVEX2VEXTablesEmitter::run(raw_ostream &OS) {
+  auto getPredicates = [&](const CodeGenInstruction *Inst) {
+    std::vector<Record *> PredicatesRecords =
+        Inst->TheDef->getValueAsListOfDefs("Predicates");
+    // Currently we only do AVX related checks and assume each instruction
+    // has one and only one AVX related predicates.
+    for (unsigned i = 0, e = PredicatesRecords.size(); i != e; ++i)
+      if (PredicatesRecords[i]->getName().startswith("HasAVX"))
+        return PredicatesRecords[i]->getValueAsString("CondString");
+    llvm_unreachable(
+        "Instruction with checkPredicate set must have one predicate!");
+  };
+
   emitSourceFileHeader("X86 EVEX2VEX tables", OS);
 
   ArrayRef<const CodeGenInstruction *> NumberedInstructions =
@@ -222,11 +253,18 @@ void X86EVEX2VEXTablesEmitter::run(raw_ostream &OS) {
       EVEX2VEX256.push_back(std::make_pair(EVEXInst, VEXInst)); // {0,1}
     else
       EVEX2VEX128.push_back(std::make_pair(EVEXInst, VEXInst)); // {0,0}
+
+    // Adding predicate check to EVEX2VEXPredicates table when needed.
+    if (VEXInst->TheDef->getValueAsBit("checkVEXPredicate"))
+      EVEX2VEXPredicates.push_back(
+          std::make_pair(EVEXInst->TheDef->getName(), getPredicates(VEXInst)));
   }
 
   // Print both tables
   printTable(EVEX2VEX128, OS);
   printTable(EVEX2VEX256, OS);
+  // Print CheckVEXInstPredicate function.
+  printCheckPredicate(EVEX2VEXPredicates, OS);
 }
 }