Request for reviews (XL): 7119644: Increase superword's vector size up to 256 bits (original) (raw)

Vladimir Kozlov vladimir.kozlov at oracle.com
Mon Jun 4 19:19:28 PDT 2012

I found an other problem. My new regression test TestShortVect failed in the overlapping case (load and store from the same array with offset). Superword code thinks store into short[] array is char store and different from short load from short[] so it allows overlapping. It happened because C2 has only one StoreC node for 2 bytes stores but different LoadS and LoadUS nodes for loads. And these load nodes has different memory type: T_SHORT and T_CHAR.

The simplest change is to add new StoreS node with memory type T_SHORT. I like this approach and will go with it if nobody object.

An other solution is to extract element type from address type instead of memory_type() for memory nodes. But it is duplication of parser code.

Note, memory_type() is called in other C2 places only to determine element size. But in Superword it is used to construct the vectors type table.

Thanks, Vladimir

Vladimir Kozlov wrote:

Most changes after latest Tom's review were done in superword.cpp and added regression tests. I think I nailed down latest issues I had with superword code. The changes pass all testing I did. Please, review it (same web link).

Thanks, Vladimir On 4/3/12 10:03 AM, Vladimir Kozlov wrote: http://cr.openjdk.java.net/~kvn/7119644/webrev

7119644: Increase superword's vector size up to 256 bits Increase superword's vector size up to 256-bits for YMM AVX registers on x86. Added generation of different vector sizes for different types of arrays in the same loop. Allow to generate small (4 bytes) vectors for loops which were unrolled small number of iterations. Add new C2 types for vectors and rework VectorNode implementation. Used MachTypeNode as base node for vector mach nodes to keep vector type. Moved XMM registers definition and vector instructions into one file x86.ad (have to rename eRegI to rRegI in x8632.ad). Tested with full CTW, NSK, C2 regression tests, JPRT and added new test. Thanks, Vladimir

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