[llvm-commits] [PATCH 09/20] [AVX] Make IntInit Unique

[Jakob Stoklund Olesen]

On Jul 19, 2011, at 1:11 PM, David Greene wrote:

> Use a DenseMap to make sure only one IntInit of any value exists.
> ---
> utils/TableGen/Record.cpp |   14 +++++++++++++-
> 1 files changed, 13 insertions(+), 1 deletions(-)
> 
> diff --git oldutils/TableGen/Record.cpp newutils/TableGen/Record.cpp
> index 4c019d3..dda0b71 100644
> --- oldutils/TableGen/Record.cpp
> +++ newutils/TableGen/Record.cpp
> @@ -491,7 +491,19 @@ const Init *BitsInit::resolveReferences(Record &R, const RecordVal *RV) const {
> }
> 
> const IntInit *IntInit::get(int64_t V) {
> -  return new IntInit(V);
> +  typedef DenseMap<int64_t, IntInit *> Pool;
> +  static Pool ThePool;
> +
> +  Pool::iterator Result = ThePool.find(V);
> + 
> +  if (Result == ThePool.end()) {
> +    IntInit *New = new IntInit(V);
> +    bool Inserted = false;
> +    tie(Result, Inserted) = ThePool.insert(std::make_pair(V, New));
> +    assert(Inserted && "Did not insert new Init into pool!");
> +  }
> +    
> +  return Result->second;
> }

This pattern is faster and simpler:

const IntInit *&I = ThePool[V];
if (!I) I = new IntInit(V);
return I;

/jakob