[llvm-dev] '__builtin_nanl' and soft-FP64 support (original) (raw)

Martin J. O'Riordan via llvm-dev llvm-dev at lists.llvm.org
Mon Sep 25 05:35:52 PDT 2017

I am seeing failures in two tests after migrating to v5.0 final, these are:

std/language.support/support.limits/limits/numeric.limits.members/quiet_NaN. pass.cpp

and:

std/language.support/support.limits/limits/numeric.limits.members/signaling_ NaN.pass.cpp

However, these are new tests and it turns out that the underlying problem is that the builtin '__builtin_nanl("")' is returning the value 0x0000000000000000. I tested this builtin with our v4.0 compiler and it has the same problem, so this is not a regression but rather an existing bug exposed by the new LibC++ implementation of ''.

But our implementation of FP64 is a software only implementation using the FP64 support functions in 'compiler-rt' and we have no lowering actions of our own.

Where should I be looking to find out how to fix this? Is it a CLang issue of an LLVM issue?

Thanks,

        MartinO

-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170925/3f506c83/attachment.html>

More information about the llvm-dev mailing list