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[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

llvm-svn: 339812
This commit is contained in:
Simon Pilgrim 2018-08-15 20:41:19 +00:00
parent 22f01268fe
commit c3c1441bda
1 changed files with 1 additions and 1 deletions
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llvm/utils/TableGen/CodeGenDAGPatterns.cpp
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@ -1278,7 +1278,7 @@ static unsigned getPatternSize(const TreePatternNode *P,
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) {