RFR: 8151439: Inline the BitMap constructor

Thomas Schatzl thomas.schatzl at oracle.com
Tue Mar 8 11:09:44 UTC 2016

Hi Stefan,

On Tue, 2016-03-08 at 11:52 +0100, Stefan Karlsson wrote:
> Hi all,
> Please review this patch to inline the BitMap constructor. This will 
> allow us to efficiently use temporary, stack-allocated BitMaps.
> http://cr.openjdk.java.net/~stefank/8151439/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8151439
> A code example of why we want to inline the BitMap constructor:
> void MyClass::set_bit(idx_t x) {
>      BitMap(&_bits, BitsPerWord).par_set_bit(x).
> }
> We could have used an instance of a BitMap in MyClass, but that would
> store both a bm_word_t* and the size of the bitmap storage in
> MyClass. 
> Since the size is a compile-time constant, we can use the above 
> construct to only store a bm_word_t field in MyClass, and thereby
> reduce 
> the size of MyClass. By inlining the constructor, we get rid of the 
> extra overhead of creating a BitMap.

  looks good.


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