This patch records the base alignment and misalignment in
innermost_loop_behavior, to avoid the second-guessing that was
previously done in vect_compute_data_ref_alignment. It also makes
vect_analyze_data_refs use dr_analyze_innermost, instead of having an
almost-copy of the same code.
I wasn't sure whether the alignments should be measured in bits
(for consistency with most other interfaces) or in bytes (for consistency
with DR_ALIGNED_TO, now DR_OFFSET_ALIGNMENT, and with *_ptr_info_alignment).
I went for bytes because:
- I think in practice most consumers are going to want bytes.
E.g. using bytes avoids having to mix TYPE_ALIGN and TYPE_ALIGN_UNIT
in vect_compute_data_ref_alignment.
- It means that any bit-level paranoia is dealt with when building
the innermost_loop_behavior and doesn't get pushed down to consumers.
2017-07-03 Richard Sandiford <richard.sandiford@linaro.org>
gcc/
* tree-data-ref.h (innermost_loop_behavior): Add base_alignment
and base_misalignment fields.
(DR_BASE_ALIGNMENT, DR_BASE_MISALIGNMENT): New macros.
* tree-data-ref.c: Include builtins.h.
(dr_analyze_innermost): Set up the new innmost_loop_behavior fields.
* tree-vectorizer.h (STMT_VINFO_DR_BASE_ALIGNMENT): New macro.
(STMT_VINFO_DR_BASE_MISALIGNMENT): Likewise.
* tree-vect-data-refs.c: Include tree-cfg.h.
(vect_compute_data_ref_alignment): Use the new innermost_loop_behavior
fields instead of calculating an alignment here.
(vect_analyze_data_refs): Use dr_analyze_innermost. Dump the new
innermost_loop_behavior fields.
From-SVN: r249916
