Single precision on MacOS

[TobiasDuswald]

I tried installing and testing superlu (v7.0.0) by running the following commands:

git clone https://github.com/xiaoyeli/superlu.git
cd superlu
mkdir build
cd build
cmake ..
make -j
make test

The tests failed for single precision and complex single precision failed:

The following tests FAILED:
      1 - s_test_9_2_0_LA (Failed)
      2 - s_test_19_2_0_LA (Failed)
      3 - s_test_2_0_SP (Failed)
      4 - s_test_9_2_10000000_LA (Failed)
      5 - s_test_19_2_10000000_LA (Failed)
      6 - s_test_2_10000000_SP (Failed)
     13 - c_test_9_2_0_LA (Failed)
     14 - c_test_19_2_0_LA (Failed)
     15 - c_test_2_0_SP (Failed)
     16 - c_test_9_2_10000000_LA (Failed)
     17 - c_test_19_2_10000000_LA (Failed)
     18 - c_test_2_10000000_SP (Failed)
Errors while running CTest

I suppose that this is related to the cmake output

-- The C compiler identification is AppleClang 15.0.0.15000309
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- SuperLU will be built as a static library.
-- Looking for sgemm_
-- Looking for sgemm_ - not found                  <-------------------- here
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Looking for dgemm_
-- Looking for dgemm_ - found
-- Found BLAS: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/System/Library/Frameworks/Accelerate.framework
-- Using TPL_BLAS_LIBRARIES='/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/System/Library/Frameworks/Accelerate.framework'
-- Will not link with METIS.
-- Configuring done (1.3s)
-- Generating done (0.6s)
-- Build files have been written to: /Users/tobiasduswald/Software/superlu/build

I also attach all logs (make , cmake, ctest). Is there a simple fix to get this running? make.log test.log cmake.log

[TobiasDuswald]

MacOS 14.5, Xcode 15.4

[TobiasDuswald]

I tried to get rid of this the warning in Cmake by adding a case for macOS to sluCnames.h but the failing tests persisted. I ran the tests in debug mode and the address sanitizer complained for the respective tests. The log is from macOS 14.5, Xcode 15.4, with cmake -DCMAKE_BUILD_TYPE="Debug" -DCMAKE_C_FLAGS="-fsanitize=address -fsanitize=undefined -glldb" ... Commit v7.0.0. test-debugbuild.log

[xiaoyeli]

Can you try using internal BLAS first, with the following cmake definition: -Denable_internal_blaslib=ON

[TobiasDuswald]

Compiling the project with cmake -Denable_internal_blaslib=ON .. && make -j && make test compiles successfully and all tests pass. 👍

[xiaoyeli]

This is good. However, the internal BLAS is not fast. You need to link with a high performance BLAS. The one you were using in Xcode does not have single precision. Alternatively, if you are not using single precision, you can disable it in cmake.

[TobiasDuswald]

I'll use double precision in any case so I'll think it should be okay. :)

I still find it a bit confusing that it compiles if there is apparently no single precision implementation available, yet yields wrong results in the tests. If it is not available, I expected errors during compilation / linking.

Also It appears to me that Xcode / Apple BLAS provides single precision interfaces (see https://developer.apple.com/documentation/accelerate/blas#1805465) but it wasn't immediately obvious to me how to include this in the library and which changes are necessary to facilitate single precision.

[xiaoyeli]

A good public domain BLAS is OpenBLAS: https://www.openblas.net/