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</o:shapelayout></xml><![endif]--></head><body lang=EN-AU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Highest integer that fits in a Int64:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>9223372036854775808<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>1e20:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>100000000000000000000<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Your Int is overflowing.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>You can’t implement Frac by going through an Integer, that will never work. Except if you have an integer that can hold 1.8E308 (which would be a 1024 bit integer, or thereabouts).<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> fpc-devel <fpc-devel-bounces@lists.freepascal.org> <b>On Behalf Of </b>Sven Barth via fpc-devel<br><b>Sent:</b> Friday, 27 April 2018 23:47<br><b>To:</b> FPC developers' list <fpc-devel@lists.freepascal.org><br><b>Cc:</b> Sven Barth <pascaldragon@googlemail.com><br><b>Subject:</b> *** GMX Spamverdacht *** Re: [fpc-devel] Broken frac function in FPC3.1.1 / Windows x86_64<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><div><div><p class=MsoNormal>Bart <<a href="mailto:bartjunk64@gmail.com">bartjunk64@gmail.com</a>> schrieb am Fr., 27. Apr. 2018, 13:42:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><p class=MsoNormal>On Wed, Apr 25, 2018 at 11:04 AM, <<a href="mailto:info@wolfgang-ehrhardt.de" target="_blank">info@wolfgang-ehrhardt.de</a>> wrote:<br><br>> If you compile and run this 64-bit program on Win 64 you get a crash<br><br>And AFAICS your analysis of the cause (see bugtracker) is correct as well.<br><br>function fpc_frac_real(d: ValReal) : ValReal;compilerproc; assembler;<br>nostackframe;<br> asm<br> cvttsd2si %xmm0,%rax<br> { Windows defines %xmm4 and %xmm5 as first non-parameter volatile registers;<br> on SYSV systems all are considered as such, so use %xmm4 }<br> cvtsi2sd %rax,%xmm4<br> subsd %xmm4,%xmm0<br> end;<br><br>CVTTSD2SI — Convert with Truncation Scalar Double-Precision<br>Floating-Point Value to Signed Integer<br>This should not be used to get a ValReal result.<o:p></o:p></p></blockquote></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The code essentially does the following (instruction by instruction):<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>=== code begin ===<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>tmpi := int64(d - trunc(d));<o:p></o:p></p></div><div><p class=MsoNormal>tmpd := double(tmpi);<o:p></o:p></p></div><div><p class=MsoNormal>Result := d - tmpd;<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>=== code end ===<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Though why it fails with the given value is a different topic... <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Regards, <o:p></o:p></p></div><div><p class=MsoNormal>Sven <o:p></o:p></p></div></div></div></div></body></html>