<div dir="rtl"><div dir="ltr"><div dir="ltr">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</div><div dir="ltr"><br></div><div dir="ltr"><a href="https://gcc.gnu.org/onlinedocs/gcc-3.2/gcc/i386-and-x86-64-Options.html">https://gcc.gnu.org/onlinedocs/gcc-3.2/gcc/i386-and-x86-64-Options.html</a></div><div dir="ltr"><br></div><div dir="ltr">-m128bit-long-double</div><div dir="ltr">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.</div><div dir="ltr">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. </div><div dir="ltr"><br></div><div dir="ltr">-m96bit-long-double</div><div dir="ltr">Set the size of long double to 96 bits as required by the i386 application binary interface. This is the default. <br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">You can check long double size out by running</div><div dir="ltr"><br></div><div dir="ltr">#include <iostream></div><div dir="ltr">int main() {</div><div dir="ltr"> long double a;</div><div dir="ltr"> std::cout<<sizeof(a)<<std::endl;</div><div dir="ltr">}</div><div dir="ltr"><br></div><div dir="ltr">which outputs 12 with mingw 32 bit, 16 with mingw 64 bit but always 16 with current clang.</div><div dir="ltr">I fixed this and added test in r245459+r245462.</div><div dir="ltr"><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div dir="ltr">2015-08-19 19:41 GMT+03:00 Hans Wennborg via cfe-commits <span dir="ltr"><<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>></span>:</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Tue, Aug 18, 2015 at 6:11 PM, Richard Smith <<a href="mailto:richard@metafoo.co.uk">richard@metafoo.co.uk</a>> wrote:<br>
> On Tue, Aug 18, 2015 at 3:01 PM, Hans Wennborg <<a href="mailto:hans@chromium.org">hans@chromium.org</a>> wrote:<br>
>><br>
>> Richard, I tried to ping you on the review thread but I'm not sure it<br>
>> got through. Martell requested this be merged to 3.7. What do you<br>
>> think?<br>
><br>
><br>
> LGTM<br>
<br>
</span>Thanks! r245456.<br>
<div class="HOEnZb"><div class="h5"><br>
><br>
>><br>
>> On Fri, Aug 14, 2015 at 12:05 PM, Martell Malone via cfe-commits<br>
>> <<a href="mailto:cfe-commits@lists.llvm.org">cfe-commits@lists.llvm.org</a>> wrote:<br>
>> > Author: martell<br>
>> > Date: Fri Aug 14 14:05:56 2015<br>
>> > New Revision: 245084<br>
>> ><br>
>> > URL: <a href="http://llvm.org/viewvc/llvm-project?rev=245084&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=245084&view=rev</a><br>
>> > Log:<br>
>> > WindowsX86: long double is x87DoubleExtended on mingw<br>
>> ><br>
>> > Summary:<br>
>> > long double on x86 mingw is 80bits and is aligned to 16bytes<br>
>> ><br>
>> > Fixes:<br>
>> > <a href="https://llvm.org/bugs/show_bug.cgi?id=24398" rel="noreferrer" target="_blank">https://llvm.org/bugs/show_bug.cgi?id=24398</a><br>
>> ><br>
>> > Reviewers: rnk<br>
>> ><br>
>> > Subscribers: cfe-commits<br>
>> ><br>
>> > Differential Revision: <a href="http://reviews.llvm.org/D12037" rel="noreferrer" target="_blank">http://reviews.llvm.org/D12037</a><br>
>> ><br>
>> > Modified:<br>
>> > cfe/trunk/lib/Basic/Targets.cpp<br>
>> ><br>
>> > Modified: cfe/trunk/lib/Basic/Targets.cpp<br>
>> > URL:<br>
>> > <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=245084&r1=245083&r2=245084&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=245084&r1=245083&r2=245084&view=diff</a><br>
>> ><br>
>> > ==============================================================================<br>
>> > --- cfe/trunk/lib/Basic/Targets.cpp (original)<br>
>> > +++ cfe/trunk/lib/Basic/Targets.cpp Fri Aug 14 14:05:56 2015<br>
>> > @@ -3784,7 +3784,10 @@ namespace {<br>
>> > class MinGWX86_32TargetInfo : public WindowsX86_32TargetInfo {<br>
>> > public:<br>
>> > MinGWX86_32TargetInfo(const llvm::Triple &Triple)<br>
>> > - : WindowsX86_32TargetInfo(Triple) {}<br>
>> > + : WindowsX86_32TargetInfo(Triple) {<br>
>> > + LongDoubleWidth = LongDoubleAlign = 128;<br>
>> > + LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;<br>
>> > + }<br>
>> > void getTargetDefines(const LangOptions &Opts,<br>
>> > MacroBuilder &Builder) const override {<br>
>> > WindowsX86_32TargetInfo::getTargetDefines(Opts, Builder);<br>
>> > @@ -4014,7 +4017,10 @@ public:<br>
>> > class MinGWX86_64TargetInfo : public WindowsX86_64TargetInfo {<br>
>> > public:<br>
>> > MinGWX86_64TargetInfo(const llvm::Triple &Triple)<br>
>> > - : WindowsX86_64TargetInfo(Triple) {}<br>
>> > + : WindowsX86_64TargetInfo(Triple) {<br>
>> > + LongDoubleWidth = LongDoubleAlign = 128;<br>
>> > + LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;<br>
>> > + }<br>
>> > void getTargetDefines(const LangOptions &Opts,<br>
>> > MacroBuilder &Builder) const override {<br>
>> > WindowsX86_64TargetInfo::getTargetDefines(Opts, Builder);<br>
>> ><br>
>> ><br>
>> > _______________________________________________<br>
>> > cfe-commits mailing list<br>
>> > <a href="mailto:cfe-commits@lists.llvm.org">cfe-commits@lists.llvm.org</a><br>
>> > <a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits" rel="noreferrer" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits</a><br>
><br>
><br>
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