[llvm] r259683 - Minor performance tweaks to llvm-tblgen (and a few that might be a good idea)

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Wed Feb  3 13:34:28 2016
New Revision: 259683

URL: http://llvm.org/viewvc/llvm-project?rev=259683&view=rev
Log:
Minor performance tweaks to llvm-tblgen (and a few that might be a good idea)

Summary:
This patch adds a reserve call to an expensive function
(`llvm::LoadIntrinsics`), and may fix a few other low hanging
performance fruit (I've put them in comments for now, so we can
discuss).

**Motivation:**

As I'm sure other developers do, when I build LLVM, I build the entire
project with the same config (`Debug`, `MinSizeRel`, `Release`, or
`RelWithDebInfo`). However, the `Debug` config also builds llvm-tblgen
in `Debug` mode. Later build steps that run llvm-tblgen then can
actually be the slowest steps in the entire build. Nobody likes slow
builds.

Reviewers: rnk, dblaikie

Differential Revision: http://reviews.llvm.org/D16832

Patch by Alexander G. Riccio

Modified:
    llvm/trunk/include/llvm/TableGen/Record.h
    llvm/trunk/utils/TableGen/CodeGenInstruction.cpp
    llvm/trunk/utils/TableGen/CodeGenTarget.cpp

Modified: llvm/trunk/include/llvm/TableGen/Record.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/TableGen/Record.h?rev=259683&r1=259682&r2=259683&view=diff
==============================================================================
--- llvm/trunk/include/llvm/TableGen/Record.h (original)
+++ llvm/trunk/include/llvm/TableGen/Record.h Wed Feb  3 13:34:28 2016
@@ -1307,9 +1307,14 @@ public:
   }
 
   bool isSubClassOf(StringRef Name) const {
-    for (const auto &SCPair : SuperClasses)
-      if (SCPair.first->getNameInitAsString() == Name)
+    for (const auto &SCPair : SuperClasses) {
+      if (const auto *SI = dyn_cast<StringInit>(SCPair.first->getNameInit())) {
+        if (SI->getValue() == Name)
+          return true;
+      } else if (SCPair.first->getNameInitAsString() == Name) {
         return true;
+      }
+    }
     return false;
   }
 

Modified: llvm/trunk/utils/TableGen/CodeGenInstruction.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenInstruction.cpp?rev=259683&r1=259682&r2=259683&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/CodeGenInstruction.cpp (original)
+++ llvm/trunk/utils/TableGen/CodeGenInstruction.cpp Wed Feb  3 13:34:28 2016
@@ -49,7 +49,9 @@ CGIOperandList::CGIOperandList(Record *R
 
   unsigned MIOperandNo = 0;
   std::set<std::string> OperandNames;
-  for (unsigned i = 0, e = InDI->getNumArgs()+OutDI->getNumArgs(); i != e; ++i){
+  unsigned e = InDI->getNumArgs() + OutDI->getNumArgs();
+  OperandList.reserve(e);
+  for (unsigned i = 0; i != e; ++i){
     Init *ArgInit;
     std::string ArgName;
     if (i < NumDefs) {

Modified: llvm/trunk/utils/TableGen/CodeGenTarget.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenTarget.cpp?rev=259683&r1=259682&r2=259683&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/CodeGenTarget.cpp (original)
+++ llvm/trunk/utils/TableGen/CodeGenTarget.cpp Wed Feb  3 13:34:28 2016
@@ -441,6 +441,7 @@ std::vector<CodeGenIntrinsic> llvm::Load
   std::vector<Record*> I = RC.getAllDerivedDefinitions("Intrinsic");
 
   std::vector<CodeGenIntrinsic> Result;
+  Result.reserve(I.size());
 
   for (unsigned i = 0, e = I.size(); i != e; ++i) {
     bool isTarget = I[i]->getValueAsBit("isTarget");
@@ -448,7 +449,7 @@ std::vector<CodeGenIntrinsic> llvm::Load
       Result.push_back(CodeGenIntrinsic(I[i]));
   }
   std::sort(Result.begin(), Result.end(),
-            [](CodeGenIntrinsic LHS, CodeGenIntrinsic RHS) {
+            [](const CodeGenIntrinsic& LHS, const CodeGenIntrinsic& RHS) {
               return LHS.Name < RHS.Name;
             });
   return Result;