On Wed, Sep 28, 2016 at 7:45 PM, Yichao Yu <yyc1...@gmail.com> wrote: > 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?
Is it http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf ? > > Thanks. > >> use the VFP ABI when compiling for that ABI. >> >> -- >> Joseph S. Myers >> jos...@codesourcery.com
