[llvm] r339884 - [TableGen] Return ValueTypeByHwMode by const reference from CodeGenRegisterClass::getValueTypeNum

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Thu Aug 16 08:29:24 2018
New Revision: 339884

URL: http://llvm.org/viewvc/llvm-project?rev=339884&view=rev
Log:
[TableGen] Return ValueTypeByHwMode by const reference from CodeGenRegisterClass::getValueTypeNum

Avoids costly std::map copies inside ValueTypeByHwMode constructor

Modified:
    llvm/trunk/utils/TableGen/CodeGenRegisters.h
    llvm/trunk/utils/TableGen/DAGISelMatcherGen.cpp

Modified: llvm/trunk/utils/TableGen/CodeGenRegisters.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenRegisters.h?rev=339884&r1=339883&r2=339884&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/CodeGenRegisters.h (original)
+++ llvm/trunk/utils/TableGen/CodeGenRegisters.h Thu Aug 16 08:29:24 2018
@@ -348,7 +348,7 @@ namespace llvm {
     ArrayRef<ValueTypeByHwMode> getValueTypes() const { return VTs; }
     unsigned getNumValueTypes() const { return VTs.size(); }
 
-    ValueTypeByHwMode getValueTypeNum(unsigned VTNum) const {
+    const ValueTypeByHwMode &getValueTypeNum(unsigned VTNum) const {
       if (VTNum < VTs.size())
         return VTs[VTNum];
       llvm_unreachable("VTNum greater than number of ValueTypes in RegClass!");

Modified: llvm/trunk/utils/TableGen/DAGISelMatcherGen.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/DAGISelMatcherGen.cpp?rev=339884&r1=339883&r2=339884&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/DAGISelMatcherGen.cpp (original)
+++ llvm/trunk/utils/TableGen/DAGISelMatcherGen.cpp Thu Aug 16 08:29:24 2018
@@ -33,15 +33,15 @@ static MVT::SimpleValueType getRegisterV
 
     if (!FoundRC) {
       FoundRC = true;
-      ValueTypeByHwMode VVT = RC.getValueTypeNum(0);
+      const ValueTypeByHwMode &VVT = RC.getValueTypeNum(0);
       if (VVT.isSimple())
         VT = VVT.getSimple().SimpleTy;
       continue;
     }
 
-    // If this occurs in multiple register classes, they all have to agree.
 #ifndef NDEBUG
-    ValueTypeByHwMode T = RC.getValueTypeNum(0);
+    // If this occurs in multiple register classes, they all have to agree.
+    const ValueTypeByHwMode &T = RC.getValueTypeNum(0);
     assert((!T.isSimple() || T.getSimple().SimpleTy == VT) &&
            "ValueType mismatch between register classes for this register");
 #endif