Revert "Export fenv functions on all platforms (#213)"
#219
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The implementation of `fesetenv` cannot be portable, as the value of `FE_DFL_ENV` differs between platforms. On FreeBSD, it is a actual environment. With glibc however, it's a sentinel -1 handled in the implementation of its floating point functions. With openlibm based on FreeBSD's libm, it assumes `FE_DFL_ENV` to be an actual environment. That assumption breaks using code that was compiled against glibc, e.g., `libcuda`: ``` Thread 1 "julia-debug" received signal SIGSEGV, Segmentation fault. 0x00007ffff7b855d0 in fesetenv () from /home/tim/Julia/julia/build/release/usr/bin/../lib/libopenlibm.so (gdb) bt ``` This reverts commit 5a27b4c. Fixes JuliaLang/julia#38427.
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If I can't remember why I did this, it can't be that important. Go ahead and do a run on the buildbots with this and let's see if it all compiles properly. |
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The implementation of
fesetenvcannot be portable, as the value ofFE_DFL_ENVdiffers between platforms. On FreeBSD, it is a actualenvironment. With glibc however, it's a sentinel -1 handled in the
implementation of its floating point functions.
https://github.com/freebsd/freebsd/blob/a41d904f70e8e9e3c3062952b52f0845af0af738/lib/msun/x86/fenv.h#L97-L99
https://github.com/bminor/glibc/blob/acdcca72940e060270e4e54d9c0457398110f409/sysdeps/x86/fpu/bits/fenv.h#L96-L97
With openlibm based on FreeBSD's libm, it assumes
FE_DFL_ENVto be anactual environment. That assumption breaks using code that was compiled
against glibc, e.g.,
libcuda:This reverts commit 5a27b4c.
Fixes JuliaLang/julia#38427.