r245084 - WindowsX86: long double is x87DoubleExtended on mingw

[Yaron Keren via cfe-commits]

Yes, worth merging with Richard approval.

2015-08-19 23:16 GMT+03:00 Hans Wennborg <hans at chromium.org>:

> I assume this is a merge request?
>
> Richard: what do you think about r245459+r245462?
>
>
>
> On Wed, Aug 19, 2015 at 10:22 AM, Yaron Keren <yaron.keren at gmail.com>
> wrote:
> > Sorry to notice late (just diagnosed the issue from a failing boost::math
> > test), according to i686 ABI, long double size on x86 is 12 bytes (the
> > memory allocated, not the underlying 80 bits register), see
> >
> > https://gcc.gnu.org/onlinedocs/gcc-3.2/gcc/i386-and-x86-64-Options.html
> >
> > -m128bit-long-double
> > Control the size of long double type. i386 application binary interface
> > specify the size to be 12 bytes, while modern architectures (Pentium and
> > newer) prefer long double aligned to 8 or 16 byte boundary. This is
> > impossible to reach with 12 byte long doubles in the array accesses.
> > Warning: if you use the -m128bit-long-double switch, the structures and
> > arrays containing long double will change their size as well as function
> > calling convention for function taking long double will be modified.
> >
> > -m96bit-long-double
> > Set the size of long double to 96 bits as required by the i386
> application
> > binary interface. This is the default.
> >
> >
> > You can check long double size out by running
> >
> > #include <iostream>
> > int main() {
> >   long double a;
> >   std::cout<<sizeof(a)<<std::endl;
> > }
> >
> > which outputs 12 with mingw 32 bit, 16 with mingw 64 bit but always 16
> with
> > current clang.
> > I fixed this and added test in r245459+r245462.
> >
> >
> > 2015-08-19 19:41 GMT+03:00 Hans Wennborg via cfe-commits
> > <cfe-commits at lists.llvm.org>:
> >>
> >> On Tue, Aug 18, 2015 at 6:11 PM, Richard Smith <richard at metafoo.co.uk>
> >> wrote:
> >> > On Tue, Aug 18, 2015 at 3:01 PM, Hans Wennborg <hans at chromium.org>
> >> > wrote:
> >> >>
> >> >> Richard, I tried to ping you on the review thread but I'm not sure it
> >> >> got through. Martell requested this be merged to 3.7. What do you
> >> >> think?
> >> >
> >> >
> >> > LGTM
> >>
> >> Thanks! r245456.
> >>
> >> >
> >> >>
> >> >> On Fri, Aug 14, 2015 at 12:05 PM, Martell Malone via cfe-commits
> >> >> <cfe-commits at lists.llvm.org> wrote:
> >> >> > Author: martell
> >> >> > Date: Fri Aug 14 14:05:56 2015
> >> >> > New Revision: 245084
> >> >> >
> >> >> > URL: http://llvm.org/viewvc/llvm-project?rev=245084&view=rev
> >> >> > Log:
> >> >> > WindowsX86: long double is x87DoubleExtended on mingw
> >> >> >
> >> >> >     Summary:
> >> >> >     long double on x86 mingw is 80bits and is aligned to 16bytes
> >> >> >
> >> >> >         Fixes:
> >> >> >     https://llvm.org/bugs/show_bug.cgi?id=24398
> >> >> >
> >> >> >     Reviewers: rnk
> >> >> >
> >> >> >     Subscribers: cfe-commits
> >> >> >
> >> >> >     Differential Revision: http://reviews.llvm.org/D12037
> >> >> >
> >> >> > Modified:
> >> >> >     cfe/trunk/lib/Basic/Targets.cpp
> >> >> >
> >> >> > Modified: cfe/trunk/lib/Basic/Targets.cpp
> >> >> > URL:
> >> >> >
> >> >> >
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=245084&r1=245083&r2=245084&view=diff
> >> >> >
> >> >> >
> >> >> >
> ==============================================================================
> >> >> > --- cfe/trunk/lib/Basic/Targets.cpp (original)
> >> >> > +++ cfe/trunk/lib/Basic/Targets.cpp Fri Aug 14 14:05:56 2015
> >> >> > @@ -3784,7 +3784,10 @@ namespace {
> >> >> >  class MinGWX86_32TargetInfo : public WindowsX86_32TargetInfo {
> >> >> >  public:
> >> >> >    MinGWX86_32TargetInfo(const llvm::Triple &Triple)
> >> >> > -      : WindowsX86_32TargetInfo(Triple) {}
> >> >> > +      : WindowsX86_32TargetInfo(Triple) {
> >> >> > +    LongDoubleWidth = LongDoubleAlign = 128;
> >> >> > +    LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;
> >> >> > +  }
> >> >> >    void getTargetDefines(const LangOptions &Opts,
> >> >> >                          MacroBuilder &Builder) const override {
> >> >> >      WindowsX86_32TargetInfo::getTargetDefines(Opts, Builder);
> >> >> > @@ -4014,7 +4017,10 @@ public:
> >> >> >  class MinGWX86_64TargetInfo : public WindowsX86_64TargetInfo {
> >> >> >  public:
> >> >> >    MinGWX86_64TargetInfo(const llvm::Triple &Triple)
> >> >> > -      : WindowsX86_64TargetInfo(Triple) {}
> >> >> > +      : WindowsX86_64TargetInfo(Triple) {
> >> >> > +    LongDoubleWidth = LongDoubleAlign = 128;
> >> >> > +    LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;
> >> >> > +  }
> >> >> >    void getTargetDefines(const LangOptions &Opts,
> >> >> >                          MacroBuilder &Builder) const override {
> >> >> >      WindowsX86_64TargetInfo::getTargetDefines(Opts, Builder);
> >> >> >
> >> >> >
> >> >> > _______________________________________________
> >> >> > cfe-commits mailing list
> >> >> > cfe-commits at lists.llvm.org
> >> >> > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
> >> >
> >> >
> >> _______________________________________________
> >> cfe-commits mailing list
> >> cfe-commits at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
> >
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20150819/6e5c7f08/attachment.html>