PING^2 [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
>>