[libcxx-commits] [PATCH] D74163: [demangler] Fix the parsing of long double literals for PowerPC and S390

Tue Feb 25 07:42:45 PST 2020

xingxue added a comment.

> I'm still wondering about Intel.  Can there ever be a literal encoded using 'g' on Intel?  If yes, then treating it as "long double" would still be wrong, because 'g' encodes IEEE128 (__float128), while "long double" is the Intel extended (80-bit) format, right?
> 
> On the other hand, if 'g' encoded literals can never happen on Intel (or other platforms), maybe it would be better to have the code handling 'g' within a #ifdef section only active on powerpc and s390?

For X86, 'e' is used for 80-bit `long double` and 'g' is used for 128-bit `long double`.  The following is the code in Clang.

  clang/lib/Basic/Targets/X86.h
  ....
  const char *getLongDoubleMangling() const override {
    return LongDoubleFormat == &llvm::APFloat::IEEEquad() ? "g" : "e";
  }
  ...

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74163/new/

https://reviews.llvm.org/D74163