[llvm] r339812 - [TableGen] Remove unnecessary TypeSetByHwMode -> ValueTypeByHwMode -> TypeSetByHwMode conversions in getPatternSize

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Wed Aug 15 13:41:19 2018
New Revision: 339812

URL: http://llvm.org/viewvc/llvm-project?rev=339812&view=rev
Log:
[TableGen] Remove unnecessary TypeSetByHwMode -> ValueTypeByHwMode -> TypeSetByHwMode conversions in getPatternSize

I noticed this during profiling of tablegen (PR28222) that we were calling Child->getType(0) which creates a ValueTypeByHwMode on the fly from the requested internal TypeSetByHwMode type and returns it by value, we then treat it as a TypeSetByHwMode reference which involves constructing a new TypeSetByHwMode on the stack with a large amount of std::map iterating/copying all along the way.

I am not an expert on tablegen, but AFAICT this is all unnecessary and we should be calling Child->getExtType(0) which returns the original TypeSetByHwMode by reference.

This gives me a 90sec reduction in msvc debug builds of x86 -gen-dag-isel.

Differential Revision: https://reviews.llvm.org/D50789

Modified:
    llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp

Modified: llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp?rev=339812&r1=339811&r2=339812&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp (original)
+++ llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp Wed Aug 15 13:41:19 2018
@@ -1278,7 +1278,7 @@ static unsigned getPatternSize(const Tre
   for (unsigned i = 0, e = P->getNumChildren(); i != e; ++i) {
     const TreePatternNode *Child = P->getChild(i);
     if (!Child->isLeaf() && Child->getNumTypes()) {
-      const TypeSetByHwMode &T0 = Child->getType(0);
+      const TypeSetByHwMode &T0 = Child->getExtType(0);
       // At this point, all variable type sets should be simple, i.e. only
       // have a default mode.
       if (T0.getMachineValueType() != MVT::Other) {