[PATCH] D121415: [FunctionAttrs] Infer argmemonly .

Mon Mar 28 07:54:23 PDT 2022

akdandrea added a comment.

In D121415#3410352 <https://reviews.llvm.org/D121415#3410352>, @fhahn wrote:

> In D121415#3408554 <https://reviews.llvm.org/D121415#3408554>, @akdandrea wrote:
>
>> Seeing a test-suite failure for benchmark `SingleSource/Benchmarks/Linpack/linpack-pc.test` with `-flto`.  This is not being seen without LTO.
>> The failing output I'm seeing is as follows:
>>
>>   ...Linux_LTO.220324/test-suite-build-2022-03-24_14-28-44/tools/fpcmp-target: Compared: 5.949578e+05 and 1.600000e+00
>>   abs. diff = 5.949562e+05 rel.diff = 3.718476e+05
>>   Out of tolerance: rel/abs: 1.000000e-04/0.000000e+00
>>
>> Reverting this commit allows it to pass.
>>
>> @fhahn let me know if you need more details to reproduce
>
> Thanks for the heads-up! I am unable to reproduce this on X86 on my system. Could you share the exact configuration & flags which cause the failure?

Ah that's interesting that you couldn't reproduce it on x86.  I did this test on a RHEL 8.4 Power system.  Here was how I compiled and ran the test:

  clang  -flto    -O3 -DNDEBUG   -w -Werror=date-time -ffp-contract=off -ffp-contract=off -DFMA_DISABLED=1 -ffp-contract=off -DFMA_DISABLED=1 -o linpack-pc.c.o   -c test-suite/SingleSource/Benchmarks/Linpack/linpack-pc.c
  clang -flto    -O3 -DNDEBUG      linpack-pc.c.o  -o linpack-pc  -lm
  .../Linux_LTO.220324/test-suite-build-2022-03-24_14-28-44/tools/timeit-target --limit-core 0 --limit-cpu 7200 --timeout 7200 --limit-file-size 104857600 --limit-rss-size 838860800 --append-exitstatus --redirect-output linpack-pc.test.out --redirect-input /dev/null --summary linpack-pc.test.time linpack-pc
  .../Linux_LTO.220324/test-suite-build-2022-03-24_14-28-44/tools/fpcmp-target -r 0.0001 linpack-pc.test.out .../Linux_LTO.220324/test-suite-build-2022-03-24_14-28-44/SingleSource/Benchmarks/Linpack/linpack-pc.reference_output

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D121415/new/

https://reviews.llvm.org/D121415