<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Hi,<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>I wrote an IR pass and it adds some instructions that are not used.<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>For example:<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='background:white'>%1 = call i64 @foo()<o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='background:white'><o:p> </o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='background:white'>When %1 is not used at all.<o:p></o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><span style='font-size:13.5pt;background:white'><o:p> </o:p></span></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>I thought that running DCE (-dce) or DIE (-die) after my pass will remove such instructions, but it didn't.<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Why? And is there a way to do that?<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Thanks,<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Tehila.<o:p></o:p></p></div></body></html>