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<p class="MsoNormal">Greetings!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sample program:<o:p></o:p></p>
<p class="MsoNormal">int main(int argc, char **argv)<o:p></o:p></p>
<p class="MsoNormal">{<o:p></o:p></p>
<p class="MsoNormal"> int myLocal=0xAA;<o:p></o:p></p>
<p class="MsoNormal"> return 0;<o:p></o:p></p>
<p class="MsoNormal">}<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Command: clang t.c –o a.o –c<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">With above simple program we are observing that clang is stat-ing and trying to open various files from lib/tls location. Eventually all calls to “lib/tls” leads to ENOENT (No such file or directory)!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><sample_strace><o:p></o:p></p>
<p class="MsoNormal">open("path/lib/tls/x86_64/libpthread.so.0", O_RDONLY) = -1 ENOENT (No such file or directory)<o:p></o:p></p>
<p class="MsoNormal">…<o:p></o:p></p>
<p class="MsoNormal">open("path/lib/tls/libpthread.so.0", O_RDONLY) = -1 ENOENT (No such file or directory)<o:p></o:p></p>
<p class="MsoNormal">…<o:p></o:p></p>
<p class="MsoNormal"></sample_strace><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The same behavior is not observed with GCC. With gcc we could build above sample program under 30 seconds while it takes more than 100 seconds when using clang!!!<o:p></o:p></p>
<p class="MsoNormal">Any pointer on how to reduce unnecessary stat/open is appreciated.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My local installation paths are…<o:p></o:p></p>
<p class="MsoNormal"> somepath/gcc-4.9.x/{bin,lib}<o:p></o:p></p>
<p class="MsoNormal"> somepath/llvm-3.7.1/{bin,lib}<o:p></o:p></p>
<p class="MsoNormal"> somepath/{bin,lib}<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In above installation path we don’t have “tls” directory.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In this regards I have following questions…<o:p></o:p></p>
<p class="MsoNormal">- We are not seeing present of “tls” directory under “somepath/llvm-3.7.1/{bin,lib}” – is anything missing in our installation?<o:p></o:p></p>
<p class="MsoNormal">- Why clang refers to “lib/tls”?<o:p></o:p></p>
<p class="MsoNormal">- Why clang refers to “lib/x86_64” ? And why not just using “lib/”<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you in advance for your help.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">-Hiral<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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