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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">It depends on if you’re using the new or old pass managers, though if you’re following that tutorial you’re probably using the old<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">one (looking at
<a href="https://llvm.org/docs/tutorial/MyFirstLanguageFrontend/LangImpl04.html#llvm-optimization-passes">
https://llvm.org/docs/tutorial/MyFirstLanguageFrontend/LangImpl04.html#llvm-optimization-passes</a>).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">If so then you can use PassManagerBuilder (<a href="http://llvm.org/doxygen/classllvm_1_1PassManagerBuilder.html">http://llvm.org/doxygen/classllvm_1_1PassManagerBuilder.html</a>).
It may be also<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">worthwhile looking at what opt does (AddOptimizationLevel.cpp in opt.cpp) as it uses PassManagerBuilder but does something<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">a bit more complex than just setting the optlevel then populating the pass manager (but maybe just setting optlevel is all you<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">need for your purposes).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">John<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> llvm-dev [mailto:llvm-dev-bounces@lists.llvm.org]
<b>On Behalf Of </b>Yafei Liu via llvm-dev<br>
<b>Sent:</b> 15 October 2019 09:54<br>
<b>To:</b> llvm-dev<br>
<b>Subject:</b> [llvm-dev] Easy way to add common pass for optimization<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Hi all, <o:p></o:p></p>
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<p class="MsoNormal">I wrote a compiler front end which generates IR codes, but due to the logic, the IR codes have a lot of instructions like unnecessary br jump, basic block creation, load instructions and expression which can be simplified.<o:p></o:p></p>
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<p class="MsoNormal">now I want to use built in passes to optimize the generated code, but after I read the tutorial: <a href="https://llvm.org/docs/tutorial/MyFirstLanguageFrontend">https://llvm.org/docs/tutorial/MyFirstLanguageFrontend</a>, I found that I
have to add passess one by one, on function level.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I know these passes for module level, but I don't know what passes I should add, and I do not have special optimization requirements, so built-in passes will meet my requirements, So this there any easy way to add most common passes which
all compilers will probable used?<o:p></o:p></p>
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