[TableGen] Use a table to lookup MVE intrinsic names

[rnk]

Summary

Speeds up compilation of SemaDeclAttr.cpp by nine seconds:

0m49.555s - > 0m40.249s

[merge_guards_bot]

Unit tests: pass. 61989 tests passed, 0 failed and 783 were skipped.

clang-tidy: unknown.

clang-format: pass.

Build artifacts: diff.json, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

[simon_tatham]

LGTM, thanks!

clang/lib/Sema/SemaDeclAttr.cpp

static void handlePatchableFunctionEntryAttr(Sema &S, Decl *D,
   }
   D->addAttr(::new (S.Context)
                  PatchableFunctionEntryAttr(S.Context, AL, Count, Offset));
 }
 
 static bool ArmMveAliasValid(unsigned BuiltinID, StringRef AliasName) {
   if (AliasName.startswith("__arm_"))
     AliasName = AliasName.substr(6);
-  switch (BuiltinID) {
 #include "clang/Basic/arm_mve_builtin_aliases.inc"
-  default:
-    return false;
-  }
 }
 
 static void handleArmMveAliasAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   if (!AL.isArgIdent(0)) {
     S.Diag(AL.getLoc(), diag::err_attribute_argument_n_type)
         << AL << 1 << AANT_ArgumentIdentifier;
     return;
   }

clang/utils/TableGen/MveEmitter.cpp

 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
+#include "llvm/TableGen/StringToOffsetTable.h"
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
 #include <list>
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
for (const auto &kv : MergeableGroups) {
     // And finally, output the code, and close the outer pair of braces. (The
     // code will always end with a 'return' statement, so we need not insert a
     // 'break' here.)
     OS << MG.Code << "}\n";
   }
 }
 
 void MveEmitter::EmitBuiltinAliases(raw_ostream &OS) {
+  // Build a sorted table of:
+  // - intrinsic id number
+  // - full name
+  // - polymorphic name or -1
+  StringToOffsetTable StringTable;
+  OS << "struct IntrinToName {\n"
+        "  uint32_t Id;\n"
+        "  int32_t FullName;\n"
+        "  int32_t ShortName;\n"
+        "};\n";
+  OS << "static const IntrinToName Map[] = {\n";
   for (const auto &kv : ACLEIntrinsics) {
     const ACLEIntrinsic &Int = *kv.second;
-    OS << "case ARM::BI__builtin_arm_mve_" << Int.fullName() << ":\n"
-       << "  return AliasName == \"" << Int.fullName() << "\"";
-    if (Int.polymorphic())
-      OS << " || AliasName == \"" << Int.shortName() << "\"";
-    OS << ";\n";
-  }
+    int32_t ShortNameOffset =
+        Int.polymorphic() ? StringTable.GetOrAddStringOffset(Int.shortName())
+                          : -1;
+    OS << "  { ARM::BI__builtin_arm_mve_" << Int.fullName() << ", "
+       << StringTable.GetOrAddStringOffset(Int.fullName()) << ", "
+       << ShortNameOffset << "},\n";
+  }
+  OS << "};\n\n";
+
+  OS << "static const char IntrinNames[] = {\n";
+  StringTable.EmitString(OS);
+  OS << "};\n\n";
+
+  OS << "auto It = std::lower_bound(std::begin(Map), "
+        "std::end(Map), BuiltinID,\n"
+        "  [](const IntrinToName &L, unsigned Id) {\n"
+        "    return L.Id < Id;\n"
+        "  });\n";
+  OS << "if (It == std::end(Map) || It->Id != BuiltinID)\n"
+        "  return false;\n";
+  OS << "StringRef FullName(&IntrinNames[It->FullName]);\n";
+  OS << "if (AliasName == FullName)\n"
+        "  return true;\n";
+  OS << "if (It->ShortName == -1)\n"
+        "  return false;\n";
+  OS << "StringRef ShortName(&IntrinNames[It->ShortName]);\n";
+  OS << "return AliasName == ShortName;\n";
 }
 
 } // namespace
 
 namespace clang {
 
 void EmitMveHeader(RecordKeeper &Records, raw_ostream &OS) {
   MveEmitter(Records).EmitHeader(OS);