RFR(S): 8085932: Fixing bugs in detecting memory alignments in SuperWord

[Civlin, Jan]

Hi All,

We would like to contribute to Fixing bugs in detecting memory alignments in SuperWord.
The contribution Bug ID:  8085932.

Please review this patch:


Bug-id:     https://bugs.openjdk.java.net/browse/JDK-8085932

webrev:  http://cr.openjdk.java.net/~kvn/8085932/webrev.00/





Description: Fixing bugs in detecting memory alignments in SuperWord





Fixing bugs in detecting memory alignments in SuperWord:
SWPointer::scaled_iv_plus_offset (fixing here a bug in detection of "scale"),
SWPointer::offset_plus_k (fixing here a bug in detection of "invariant"),

Add tracing output to the code that deal with memory alignment. The following routines are traceable:

SWPointer::scaled_iv_plus_offset
SWPointer::offset_plus_k
SWPointer::scaled_iv,
WPointer::SWPointer,
SuperWord::memory_alignment

Tracing is done only for NOT_PRODUCT. Currently tracing is controlled by VectorizeDebug:

#ifndef PRODUCT
  if (_phase->C->method() != NULL) {
       _phase->C->method()->has_option_value("VectorizeDebug", _vector_loop_debug);
  }
#endif

And VectorizeDebug may take any combination (bitwise OR) of the following values:
bool is_trace_alignment() { return (_vector_loop_debug & 2) > 0; }
bool is_trace_mem_slice() { return (_vector_loop_debug & 4) > 0; }
bool is_trace_loop() { return (_vector_loop_debug & 8) > 0; }
bool is_trace_adjacent() { return (_vector_loop_debug & 16) > 0; }
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