topic Re: Compiler Bugs (use different registers) in Intel® oneAPI DPC++/C++ Compiler https://community.intel.com/t5/Intel-oneAPI-DPC-C-Compiler/Compiler-Bugs-use-different-registers/m-p/1607575#M3878 <P><SPAN>ICC has been deprecated and removed from our oneAPI Base Toolkit since later versions in 2023. Please migrate to using ICX compiler instead.&nbsp;</SPAN></P> Tue, 18 Jun 2024 06:03:34 GMT Alex_Y_Intel 2024-06-18T06:03:34Z Compiler Bugs (use different registers) https://community.intel.com/t5/Intel-oneAPI-DPC-C-Compiler/Compiler-Bugs-use-different-registers/m-p/1606087#M3856 <P>I discovered that ICC 2021.10.0 sometimes overlooks memory size directives.</P><P>I found that ICC incorrectly checks memory size for 11 opcodes when compiling x64 or x86 binaries.</P><P>&nbsp;</P><P>The buggy code contains 11 opcodes.</P><DIV><DIV><TABLE border="1" width="100%"><TBODY><TR><TD width="100%"><DIV><DIV><SPAN>void</SPAN><SPAN> bug</SPAN><SPAN>(</SPAN><SPAN>int</SPAN><SPAN> num</SPAN><SPAN>)</SPAN> <SPAN>{</SPAN></DIV><DIV><SPAN>__asm__</SPAN><SPAN>(</SPAN><SPAN>".intel_syntax noprefix\n"</SPAN></DIV><DIV><SPAN>"cldemote ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"clflush ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"clflushopt ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"clwb ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"invlpg ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"prefetch ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"prefetchw ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"prefetcht0 ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"prefetcht1 ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"prefetcht2 ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>"prefetchwt1 ZMMWORD PTR [1]\n"</SPAN></DIV><DIV><SPAN>);</SPAN></DIV><DIV><SPAN>}</SPAN></DIV></DIV></TD></TR></TBODY></TABLE></DIV></DIV><P>&nbsp;</P><P>Compiled Code</P><TABLE border="1" width="100%"><TBODY><TR><TD width="100%"><DIV><DIV><SPAN>bug:</SPAN></DIV><DIV><SPAN>push</SPAN> <SPAN>rbp</SPAN></DIV><DIV><SPAN>mov</SPAN> <SPAN>rbp</SPAN><SPAN>,</SPAN><SPAN>rsp</SPAN></DIV><DIV><SPAN>sub</SPAN> <SPAN>rsp</SPAN><SPAN>,</SPAN><SPAN>0x10</SPAN></DIV><DIV><SPAN>mov</SPAN> <SPAN>DWORD</SPAN> <SPAN>PTR</SPAN> <SPAN>[</SPAN><SPAN>rbp</SPAN><SPAN>-</SPAN><SPAN>0x10</SPAN><SPAN>]</SPAN><SPAN>,</SPAN><SPAN>edi</SPAN></DIV><DIV><SPAN>cldemote</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>clflush</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>clflushopt</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>clwb</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>invlpg</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>prefetch</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>prefetchw</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>prefetcht0</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>prefetcht1</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>prefetcht2</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>prefetchwt1</SPAN> <SPAN>BYTE</SPAN> <SPAN>PTR</SPAN> <SPAN>ds</SPAN><SPAN>:</SPAN><SPAN>0x1</SPAN></DIV><DIV><SPAN>leave</SPAN></DIV><DIV><SPAN>ret</SPAN></DIV></DIV></TD></TR></TBODY></TABLE><P>&nbsp;</P><P>You can replay the bug through the godbolt.</P><P><A href="https://godbolt.org/z/7Ka8na468" target="_blank" rel="noopener">https://godbolt.org/z/7Ka8na468</A></P> Wed, 12 Jun 2024 09:57:47 GMT https://community.intel.com/t5/Intel-oneAPI-DPC-C-Compiler/Compiler-Bugs-use-different-registers/m-p/1606087#M3856 hyungseok 2024-06-12T09:57:47Z Re: Compiler Bugs (use different registers) https://community.intel.com/t5/Intel-oneAPI-DPC-C-Compiler/Compiler-Bugs-use-different-registers/m-p/1607575#M3878 <P><SPAN>ICC has been deprecated and removed from our oneAPI Base Toolkit since later versions in 2023. Please migrate to using ICX compiler instead.&nbsp;</SPAN></P> Tue, 18 Jun 2024 06:03:34 GMT https://community.intel.com/t5/Intel-oneAPI-DPC-C-Compiler/Compiler-Bugs-use-different-registers/m-p/1607575#M3878 Alex_Y_Intel 2024-06-18T06:03:34Z