PING^3 [PATCH 0/9] rs6000: Rework rs6000_emit_vector_compare

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi,

Gentle ping this series:

https://gcc.gnu.org/pipermail/gcc-patches/2022-November/607146.html

BR,
Kewen

> 
>>
>> on 2022/11/24 17:15, Kewen Lin wrote:
>>> Hi,
>>>
>>> Following Segher's suggestion, this patch series is to rework
>>> function rs6000_emit_vector_compare for vector float and int
>>> in multiple steps, it's based on the previous attempts [1][2].
>>> As mentioned in [1], the need to rework this for float is to
>>> make a centralized place for vector float comparison handlings
>>> instead of supporting with swapping ops and reversing code etc.
>>> dispersedly.  It's also for a subsequent patch to handle
>>> comparison operators with or without trapping math (PR105480).
>>> With the handling on vector float reworked, we can further make
>>> the handling on vector int simplified as shown.
>>>
>>> For Segher's concern about whether this rework causes any
>>> assembly change, I constructed two testcases for vector float[3]
>>> and int[4] respectively before, it showed the most are fine
>>> excepting for the difference on LE and UNGT, it's demonstrated
>>> as improvement since it uses GE instead of GT ior EQ.  The
>>> associated test case in patch 3/9 is a good example.
>>>
>>> Besides, w/ and w/o the whole patch series, I built the whole
>>> SPEC2017 at options -O3 and -Ofast separately, checked the
>>> differences on object assembly.  The result showed that the
>>> most are unchanged, except for:
>>>
>>>   * at -O3, 521.wrf_r has 9 object files and 526.blender_r has
>>>     9 object files with differences.
>>>
>>>   * at -Ofast, 521.wrf_r has 12 object files, 526.blender_r has
>>>     one and 527.cam4_r has 4 object files with differences.
>>>
>>> By looking into these differences, all significant differences
>>> are caused by the known improvement mentined above transforming
>>> GT ior EQ to GE, which can also affect unrolling decision due
>>> to insn count.  Some other trivial differences are branch
>>> target offset difference, nop difference for alignment, vsx
>>> register number differences etc.
>>>
>>> I also evaluated the runtime performance for these changed
>>> benchmarks, the result is neutral.
>>>
>>> These patches are bootstrapped and regress-tested
>>> incrementally on powerpc64-linux-gnu P7 & P8, and
>>> powerpc64le-linux-gnu P9 & P10.
>>>
>>> Is it ok for trunk?
>>>
>>> BR,
>>> Kewen
>>> -----
>>> [1] https://gcc.gnu.org/pipermail/gcc-patches/2022-November/606375.html
>>> [2] https://gcc.gnu.org/pipermail/gcc-patches/2022-November/606376.html
>>> [3] https://gcc.gnu.org/pipermail/gcc-patches/2022-November/606504.html
>>> [4] https://gcc.gnu.org/pipermail/gcc-patches/2022-November/606506.html
>>>
>>> Kewen Lin (9):
>>>   rs6000: Rework vector float comparison in rs6000_emit_vector_compare - p1
>>>   rs6000: Rework vector float comparison in rs6000_emit_vector_compare - p2
>>>   rs6000: Rework vector float comparison in rs6000_emit_vector_compare - p3
>>>   rs6000: Rework vector float comparison in rs6000_emit_vector_compare - p4
>>>   rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p1
>>>   rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p2
>>>   rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p3
>>>   rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p4
>>>   rs6000: Rework vector integer comparison in rs6000_emit_vector_compare - p5
>>>
>>>  gcc/config/rs6000/rs6000.cc                 | 180 ++++++--------------
>>>  gcc/testsuite/gcc.target/powerpc/vcond-fp.c |  25 +++
>>>  2 files changed, 74 insertions(+), 131 deletions(-)
>>>  create mode 100644 gcc/testsuite/gcc.target/powerpc/vcond-fp.c
>>>