On Wed, Sep 28, 2016 at 7:39 PM, Joseph Myers <jos...@codesourcery.com> wrote: > On Wed, 28 Sep 2016, Yichao Yu wrote: > >> In particular, it seems that on all the platforms with a >> arm*-*-gnueabihf triple I've checked (alarm armv7h, alarm armv6h, >> debian armhf, fedora armv7hl) the __powidf2 function (and possibly >> many others) are compiled with the AAPCS VFP calling convention, which >> is also how it is used by gcc. However, LLVM dev (CC'd) claims that >> these routines are meant to be always using soft floating point >> calling convention even on platforms using hard floating point ABI. > > The RTABI functions should use the base AAPCS calling conventions. That > was something I dealt with when working on the implementation of the VFP > ABI variant <https://gcc.gnu.org/ml/gcc-patches/2009-05/msg00591.html>. > > Except where an external ABI defines things like that, the normal > expectation for libgcc functions is that they have the same ABI as for an > ordinary C function with the same prototype. That is, since libgcc.texi > gives a prototype for __powidf2 without saying anything special about its > ABI, and since it is not a function defined in RTABI, it can be taken to
I guess other ppl on the list probably know this but what's the list of function in RTABI? Thanks. > use the VFP ABI when compiling for that ABI. > > -- > Joseph S. Myers > jos...@codesourcery.com
