Fixes constexpr errors with frounding-math on gcc < 10. #4278

Chrismarsh · 2021-08-31T18:42:02Z

Use std::numeric_limits digits10 instead of bespoke version
trilinos/Trilinos#9056
#4267

Use std::numeric_limits digits10 instead of bespoke version trilinos/Trilinos/issues/9056 kokkos/issues/4267

dalg24-jenkins · 2021-08-31T18:42:04Z

Can one of the admins verify this patch?

masterleinad · 2021-08-31T18:51:08Z

core/src/Kokkos_NumericTraits.hpp

 #define DIGITS10_HELPER_INTEGRAL(TYPE) \
-template <> struct digits10_helper<TYPE> { static constexpr int value = digits_helper<TYPE>::value * log10_2; };
+template <> struct digits10_helper<TYPE> { static constexpr int value = std::numeric_limits<TYPE>::digits10; };


You can't use std::numeric_limits. This is not available in all backends and for all relevant configurations.

Ok I've fixed that. Was not aware sorry.

…ackends and follow gcc's constexpr-valid approximation of log10(2)

Chrismarsh · 2021-08-31T19:08:06Z

hi @masterleinad, oh ok. I've amended this PR to use
8 * 643L / 2136.

This follows the log10_2 approximation in gcc.

It is not clear to me why the 8bit is baked into the log10_2 constant, so I've just made that more clear

masterleinad · 2021-08-31T19:38:08Z

It is not clear to me why the 8bit is baked into the log10_2 constant, so I've just made that more clear

That might be a bug. I am seeing

for

std::cout << Kokkos::Experimental::digits10<bool>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<char>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<signed char>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<unsigned char>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<short>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<unsigned short>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<int>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<unsigned int>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<long int>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<unsigned long int>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<long long int>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<unsigned long long int>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<float>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<double>::value << std::endl;
std::cout << Kokkos::Experimental::digits10<long double>::value << std::endl;

but std::numeric_limits<>::digits10 gives me

see https://godbolt.org/z/K7W4jfx64.

masterleinad · 2021-08-31T19:51:21Z

The compiler bug is described at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96862. I am wondering whether the workaround here really covers all situations or it just fails for another value. Would you mind checking if you can compile all Kokkos unit tests with -frounding-math using the problematic compiler?

masterleinad · 2021-08-31T19:54:21Z

core/src/Kokkos_NumericTraits.hpp

@@ -141,7 +141,7 @@ template <> struct digits_helper<double> { static constexpr int value = DBL_MANT
 template <> struct digits_helper<long double> { static constexpr int value = LDBL_MANT_DIG; };
 template <class> struct digits10_helper {};
 template <> struct digits10_helper<bool> { static constexpr int value = 0; };
-constexpr double log10_2 = 2.41;
+constexpr double log10_2 = 8*643L/2136; // The fraction 643/2136 approximates log10(2) to 7 significant digits. Follows gcc impl


Shouldn't this be

Suggested change

constexpr double log10_2 = 8*643L/2136; // The fraction 643/2136 approximates log10(2) to 7 significant digits. Follows gcc impl

constexpr double log10_2 = 643./2136; // The fraction 643/2136 approximates log10(2) to 7 significant digits. Follows gcc impl

? Note both the multiplication with 8here and making sure the fraction is computed as a floating-point number.

I don't believe so.

a) It appears that any floating point in constexpr under -frounding-math will trigger that bug, so constexpr double log10_2 = 643./2136; puts us back to where we started.

b) The result needs to be rounded down, as having 2.41 digits makes no sense. AFAIK int/int rounds to 0, which is correct and desired. Indeed I think this log10_2 should actually be a constexpr int, not double.

Well, your code in the godbolt link shows that what you are proposing is equivalent to double log10_2=2 which gives wrong results when compared to std::numeric_limits<>::digits10. I think I would in the end be OK with just hardcoding the values for digits10 instead of computing them at compile-time as workaround.

dalg24 · 2021-08-31T22:35:26Z

For reference https://godbolt.org/z/Kh6v4Ezs3

dalg24 · 2021-08-31T22:35:36Z

OK to test

Chrismarsh · 2021-09-01T02:28:06Z

Would you mind checking if you can compile all Kokkos unit tests with -frounding-math using the problematic compiler?

$ CXXFLAGS=-frounding-math cmake ../kokkos/ -DCMAKE_INSTALL_PREFIX=~/install-kokkos  -DKokkos_ENABLE_TESTS=On
  [...]

$ make
[...] successfully builds

$ make test
Running tests...
Test project /globalhome/cbm038/HPC/build-kokkos
      Start  1: KokkosCore_UnitTest_Serial1
 1/41 Test  #1: KokkosCore_UnitTest_Serial1 ..................   Passed   16.19 sec
      Start  2: KokkosCore_UnitTest_Serial2
 2/41 Test  #2: KokkosCore_UnitTest_Serial2 ..................   Passed    2.71 sec
      Start  3: KokkosCore_UnitTest_SerialGraph
 3/41 Test  #3: KokkosCore_UnitTest_SerialGraph ..............   Passed    0.01 sec
      Start  4: KokkosCore_UnitTest_Default
 4/41 Test  #4: KokkosCore_UnitTest_Default ..................   Passed    0.02 sec
      Start  5: KokkosCore_UnitTest_PushFinalizeHook
 5/41 Test  #5: KokkosCore_UnitTest_PushFinalizeHook .........   Passed    0.01 sec
      Start  6: KokkosCore_UnitTest_Develop
 6/41 Test  #6: KokkosCore_UnitTest_Develop ..................   Passed    0.01 sec
      Start  7: KokkosCore_UnitTest_LogicalSpaces
 7/41 Test  #7: KokkosCore_UnitTest_LogicalSpaces ............   Passed    0.01 sec
      Start  8: KokkosCore_UnitTest_EventCorrectness
 8/41 Test  #8: KokkosCore_UnitTest_EventCorrectness .........   Passed    0.01 sec
      Start  9: KokkosCore_ProfilingTestLibraryLoadHelp
 9/41 Test  #9: KokkosCore_ProfilingTestLibraryLoadHelp ......   Passed    0.01 sec
      Start 10: KokkosCore_ProfilingTestLibraryCmdLineHelp
10/41 Test #10: KokkosCore_ProfilingTestLibraryCmdLineHelp ...   Passed    0.01 sec
      Start 11: KokkosCore_ProfilingTestLibraryLoad
11/41 Test #11: KokkosCore_ProfilingTestLibraryLoad ..........   Passed    0.01 sec
      Start 12: KokkosCore_ProfilingTestLibraryCmdLine
12/41 Test #12: KokkosCore_ProfilingTestLibraryCmdLine .......   Passed    0.01 sec
      Start 13: KokkosCore_UnitTest_StackTraceTest
13/41 Test #13: KokkosCore_UnitTest_StackTraceTest ...........   Passed    0.02 sec
      Start 14: KokkosCore_UnitTest_DefaultInit_1
14/41 Test #14: KokkosCore_UnitTest_DefaultInit_1 ............   Passed    0.01 sec
      Start 15: KokkosCore_UnitTest_DefaultInit_2
15/41 Test #15: KokkosCore_UnitTest_DefaultInit_2 ............   Passed    0.01 sec
      Start 16: KokkosCore_UnitTest_DefaultInit_3
16/41 Test #16: KokkosCore_UnitTest_DefaultInit_3 ............   Passed    0.01 sec
      Start 17: KokkosCore_UnitTest_DefaultInit_4
17/41 Test #17: KokkosCore_UnitTest_DefaultInit_4 ............   Passed    0.01 sec
      Start 18: KokkosCore_UnitTest_DefaultInit_5
18/41 Test #18: KokkosCore_UnitTest_DefaultInit_5 ............   Passed    0.01 sec
      Start 19: KokkosCore_UnitTest_DefaultInit_6
19/41 Test #19: KokkosCore_UnitTest_DefaultInit_6 ............   Passed    0.01 sec
      Start 20: KokkosCore_UnitTest_DefaultInit_7
20/41 Test #20: KokkosCore_UnitTest_DefaultInit_7 ............   Passed    0.01 sec
      Start 21: KokkosCore_UnitTest_DefaultInit_8
21/41 Test #21: KokkosCore_UnitTest_DefaultInit_8 ............   Passed    0.01 sec
      Start 22: KokkosCore_UnitTest_DefaultInit_9
22/41 Test #22: KokkosCore_UnitTest_DefaultInit_9 ............   Passed    0.01 sec
      Start 23: KokkosCore_UnitTest_DefaultInit_10
23/41 Test #23: KokkosCore_UnitTest_DefaultInit_10 ...........   Passed    0.01 sec
      Start 24: KokkosCore_UnitTest_DefaultInit_11
24/41 Test #24: KokkosCore_UnitTest_DefaultInit_11 ...........   Passed    0.01 sec
      Start 25: KokkosCore_UnitTest_DefaultInit_12
25/41 Test #25: KokkosCore_UnitTest_DefaultInit_12 ...........   Passed    0.01 sec
      Start 26: KokkosCore_UnitTest_DefaultInit_13
26/41 Test #26: KokkosCore_UnitTest_DefaultInit_13 ...........   Passed    0.01 sec
      Start 27: KokkosCore_UnitTest_DefaultInit_14
27/41 Test #27: KokkosCore_UnitTest_DefaultInit_14 ...........   Passed    0.01 sec
      Start 28: KokkosCore_UnitTest_DefaultInit_15
28/41 Test #28: KokkosCore_UnitTest_DefaultInit_15 ...........   Passed    0.01 sec
      Start 29: KokkosCore_UnitTest_DefaultInit_16
29/41 Test #29: KokkosCore_UnitTest_DefaultInit_16 ...........   Passed    0.01 sec
      Start 30: KokkosCore_UnitTest_DefaultInit_17
30/41 Test #30: KokkosCore_UnitTest_DefaultInit_17 ...........   Passed    0.01 sec
      Start 31: KokkosCore_UnitTest_DefaultInit_18
31/41 Test #31: KokkosCore_UnitTest_DefaultInit_18 ...........   Passed    0.01 sec
      Start 32: KokkosCore_IncrementalTest_SERIAL
32/41 Test #32: KokkosCore_IncrementalTest_SERIAL ............   Passed    0.20 sec
      Start 33: KokkosCore_UnitTest_CTestDevice
33/41 Test #33: KokkosCore_UnitTest_CTestDevice ..............   Passed    0.01 sec
      Start 34: KokkosCore_UnitTest_CMakePassCmdLineArgs0
34/41 Test #34: KokkosCore_UnitTest_CMakePassCmdLineArgs0 ....   Passed    0.01 sec
      Start 35: KokkosCore_PerfTestExec
35/41 Test #35: KokkosCore_PerfTestExec ......................   Passed  128.86 sec
      Start 36: KokkosCore_PerformanceTest_Atomic
36/41 Test #36: KokkosCore_PerformanceTest_Atomic ............   Passed    0.05 sec
      Start 37: KokkosCore_PerformanceTest_Atomic_MinMax
37/41 Test #37: KokkosCore_PerformanceTest_Atomic_MinMax .....   Passed    0.20 sec
      Start 38: KokkosCore_PerformanceTest_Mempool
38/41 Test #38: KokkosCore_PerformanceTest_Mempool ...........   Passed    0.01 sec
      Start 39: KokkosCore_PerformanceTest_TaskDag
39/41 Test #39: KokkosCore_PerformanceTest_TaskDag ...........   Passed    0.01 sec
      Start 40: KokkosContainers_UnitTest_Serial
40/41 Test #40: KokkosContainers_UnitTest_Serial .............   Passed   14.95 sec
      Start 41: KokkosAlgorithms_UnitTest
41/41 Test #41: KokkosAlgorithms_UnitTest ....................   Passed   13.98 sec

100% tests passed, 0 tests failed out of 41

Total Test time (real) = 177.50 sec

This is with this PR -- is that what you wanted? Or did it want it pre-PR changes?

dalg24 · 2021-09-01T02:36:38Z

core/src/Kokkos_NumericTraits.hpp

@@ -141,7 +141,7 @@ template <> struct digits_helper<double> { static constexpr int value = DBL_MANT
 template <> struct digits_helper<long double> { static constexpr int value = LDBL_MANT_DIG; };
 template <class> struct digits10_helper {};
 template <> struct digits10_helper<bool> { static constexpr int value = 0; };
-constexpr double log10_2 = 2.41;
+constexpr int log10_2 = 8*643L/2136; // The fraction 643/2136 approximates log10(2) to 7 significant digits. Follows gcc impl


~~This yields 0~~ I missed the 8. As Daniel pointed out it yields 2

masterleinad · 2021-09-01T04:02:43Z

This is with this PR -- is that what you wanted? Or did it want it pre-PR changes?

That should be fine.

crtrott · 2021-09-01T14:19:46Z

#4281 supercedes this including a test and it is NOT passing tests on all compilers .

Chrismarsh · 2021-09-01T14:25:52Z

Given this PR is addressing two problems and half of it is, seemingly, quite fiddly and better dealt with in #4281 as a separate PR, I think this should be amended to only address the core/src/Kokkos_Tuners.hpp change. What do you think?

crtrott · 2021-09-01T14:37:38Z

Yeah we could just get the tuner thing through separately.

core/src/Kokkos_Tuners.hpp

Co-authored-by: Damien L-G <dalg24+github@gmail.com>

core/src/Kokkos_Tuners.hpp

…pull/4105, kokkos/kokkos/pull/4278, kokkos/kokkos/pull/4281

crtrott · 2021-09-01T23:32:14Z

ok you can't make it const ... because then the copy constructor and assignment doesn't work (which ignores constexpr stuff I guess).

Chrismarsh · 2021-09-02T02:19:54Z

Yes I'm seeing the same thing on a macos version I don't have locally. I'll remove it.

crtrott · 2021-09-02T15:48:04Z

Retest this please.

Fixes constexpr errors with frounding-math on gcc < 10.

34cbd3d

Use std::numeric_limits digits10 instead of bespoke version trilinos/Trilinos/issues/9056 kokkos/issues/4267

Chrismarsh mentioned this pull request Aug 31, 2021

Kokkos/ROL: build failure with gcc-9.3.0 trilinos/Trilinos#9056

Closed

masterleinad reviewed Aug 31, 2021

View reviewed changes

Remove limits + std::numeric_limits as this is not available on all b…

f1d4539

…ackends and follow gcc's constexpr-valid approximation of log10(2)

masterleinad reviewed Aug 31, 2021

View reviewed changes

Update the log10_2 type to int

8d969f4

dalg24 reviewed Sep 1, 2021

View reviewed changes

dalg24 mentioned this pull request Sep 1, 2021

Bug in digits10 numeric characteristics traits #4280

Closed

dalg24 mentioned this pull request Sep 1, 2021

Fix digits10 bug #4281

Merged

Revert log10_2 changes en lieu of kokkos/pull/4281

e0fb04c

crtrott approved these changes Sep 1, 2021

View reviewed changes

dalg24 reviewed Sep 1, 2021

View reviewed changes

core/src/Kokkos_Tuners.hpp Show resolved Hide resolved

dalg24 requested a review from DavidPoliakoff September 1, 2021 15:34

declare const

5d5635c

Co-authored-by: Damien L-G <dalg24+github@gmail.com>

masterleinad reviewed Sep 1, 2021

View reviewed changes

core/src/Kokkos_Tuners.hpp Outdated Show resolved Hide resolved

update comment

e6bc7da

crtrott added the Blocks Promotion Overview issue for release-blocking bugs label Sep 1, 2021

Chrismarsh added a commit to Chrismarsh/conan-trilinos that referenced this pull request Sep 1, 2021

Add trilinos with Kokkos with following PRs merged in: kokkos/kokkos/…

da0d24e

…pull/4105, kokkos/kokkos/pull/4278, kokkos/kokkos/pull/4281

remove const as it causes various ctors to be implicitly deleted

baa4d8e

Chrismarsh added a commit to Chrismarsh/Trilinos that referenced this pull request Sep 2, 2021

remove const inline with kokkos/kokkos/pull/4278

c62bb3a

crtrott merged commit ae270a1 into kokkos:develop Sep 2, 2021

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Fixes constexpr errors with frounding-math on gcc < 10. #4278

Fixes constexpr errors with frounding-math on gcc < 10. #4278

Chrismarsh commented Aug 31, 2021 •

edited by masterleinad

Loading

dalg24-jenkins commented Aug 31, 2021

masterleinad Aug 31, 2021

Chrismarsh Aug 31, 2021

Chrismarsh commented Aug 31, 2021

masterleinad commented Aug 31, 2021

masterleinad commented Aug 31, 2021

masterleinad Aug 31, 2021

Chrismarsh Sep 1, 2021

masterleinad Sep 1, 2021

dalg24 commented Aug 31, 2021

dalg24 commented Aug 31, 2021

Chrismarsh commented Sep 1, 2021 •

edited

Loading

dalg24 Sep 1, 2021 •

edited

Loading

masterleinad commented Sep 1, 2021

crtrott commented Sep 1, 2021

Chrismarsh commented Sep 1, 2021

crtrott commented Sep 1, 2021

crtrott commented Sep 1, 2021

Chrismarsh commented Sep 2, 2021

crtrott commented Sep 2, 2021

	constexpr double log10_2 = 8*643L/2136; // The fraction 643/2136 approximates log10(2) to 7 significant digits. Follows gcc impl
	constexpr double log10_2 = 643./2136; // The fraction 643/2136 approximates log10(2) to 7 significant digits. Follows gcc impl

Fixes constexpr errors with frounding-math on gcc < 10. #4278

Fixes constexpr errors with frounding-math on gcc < 10. #4278

Conversation

Chrismarsh commented Aug 31, 2021 • edited by masterleinad Loading

dalg24-jenkins commented Aug 31, 2021

masterleinad Aug 31, 2021

Choose a reason for hiding this comment

Chrismarsh Aug 31, 2021

Choose a reason for hiding this comment

Chrismarsh commented Aug 31, 2021

masterleinad commented Aug 31, 2021

masterleinad commented Aug 31, 2021

masterleinad Aug 31, 2021

Choose a reason for hiding this comment

Chrismarsh Sep 1, 2021

Choose a reason for hiding this comment

masterleinad Sep 1, 2021

Choose a reason for hiding this comment

dalg24 commented Aug 31, 2021

dalg24 commented Aug 31, 2021

Chrismarsh commented Sep 1, 2021 • edited Loading

dalg24 Sep 1, 2021 • edited Loading

Choose a reason for hiding this comment

masterleinad commented Sep 1, 2021

crtrott commented Sep 1, 2021

Chrismarsh commented Sep 1, 2021

crtrott commented Sep 1, 2021

crtrott commented Sep 1, 2021

Chrismarsh commented Sep 2, 2021

crtrott commented Sep 2, 2021

Chrismarsh commented Aug 31, 2021 •

edited by masterleinad

Loading

Chrismarsh commented Sep 1, 2021 •

edited

Loading

dalg24 Sep 1, 2021 •

edited

Loading