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with Intel compiler, SIMD exp test fails in double+release - Redmine #2335

Both ICC 17.4 and 18.1 in double both for AVX2 and AVX512_KNL (AVX512 not tested)

[ RUN ] SimdMathTest.exp
../src/gromacs/simd/tests/simd_math.cpp:430: Failure
Failing SIMD math function ulp comparison between std::exp and exp
Requested ulp tolerance: 2048
Requested abs tolerance: 0
Denormals can be 0: false
Largest Ulp difference occurs for x=–708.39999999999998
Ref values: 2.2250738585072014e-308
SIMD values: 0
Ulp diff.: 4503599627370496

[ FAILED ] SimdMathTest.exp (4 ms)
[ RUN ] SimdMathTest.expUnsafe
../src/gromacs/simd/tests/simd_math.cpp:466: Failure
Failing SIMD math function ulp comparison between std::exp and expMathOptimization::Unsafe
Requested ulp tolerance: 2048
Requested abs tolerance: 0
Denormals can be 0: false
Largest Ulp difference occurs for x=–708.39999999999998
Ref values: 2.2250738585072014e-308
SIMD values: 0
Ulp diff.: 4503599627370496

[ FAILED ] SimdMathTest.expUnsafe (1 ms)

(from redmine: issue id 2335, created on 2017-12-07 by rolandschulz, closed on 2018-01-03)

  • Changesets:
    • Revision 013509bf by Roland Schulz on 2017-12-07T17:58:41Z:
Fix exp test for ICC in double

Fixes #2335

Change-Id: I5f688c64d59e8d2a23239fc945756bcc5130d15b
  • Revision 80dd3f5b by Mark Abraham on 2017-12-21T09:54:24Z:
Update double-precision test configurations

These changes improve coverage of double precision, using more release
mode, particularly with latest gcc and icc, and using 128-bit SIMD,
which have been cases that were buggy recently. The other aspects of
the configurations that have been modified have been
non-critical. Where appropriate, brief rationales are recorded. This
resolves an old TODO item in the post-submit matrix.

Fixed a sign mismatch in initializing an OpenCL variable that didn't
need to be initialized.

Noted relevant new TODOs.

Refs #2300, #2325, #2326, #2334, #2335, #2336, #2337, #2338

Change-Id: I131fa1a6776d1e7809799c3f931a1fc8100fcdc9
  • Revision 5209a517 by Erik Lindahl on 2018-01-03T10:59:42Z:
Avoid FTZ triggering simd test failures

For very small arguments on platforms without
FMA support, the Intel compiler's default
usage of flush-to-zero for denormal values can
lead to slight deviations. Since this is a
range we really don't care about, and non-FMA
platforms are anyway a thing of the past, just
avoid testing a very small range around that
threshold for non-FMA SIMD platforms.

Fixes #2335.

Change-Id: I7cfb14284e79534f114891ba4dcd1f1c7223faf3
  • Revision 1f2109b7 by Szilárd Páll on 2018-03-29T12:11:02Z:
Tweak/enable icc 18 post-submit tests

SIMD was disabled due to #2335

Change-Id: Ia55742958cfbdfb75e96c8d2b0ba5620a57a6f56