<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span><br></span></div><div><span>Hi Evan.</span></div><div><span style="font-size: 12pt; ">The hasSideEffects method I believe operates only on Inline Assembly (IA) blocks. What if such a sequence is not part of IA?</span><br></div><div><span style="font-size: 12pt; "><br></span></div><div><span style="font-size: 12pt; ">Thanks.</span></div><div><span style="font-size: 12pt; ">Girish.</span></div><div><span><br></span></div><div></div><div><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; margin-top: 5px; padding-left: 5px;"><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; ">If an instruction is marked as side-effect free then it's a candidate for CSE. Try marking the
instruction with hasSideEffects.<br><br>Evan<br><br>On Dec 17, 2011, at 12:24 PM, Johannes Birgmeier wrote:<br><br>> Hello,<br>> <br>> I'm writing for a backend and have a complicated instruction bundle (3 <br>> instructions) that has to be executed like a single block (meaning: if <br>> the first instruction is executed, all three have to be executed to <br>> obtain the result, though not necessarily without other instructions in <br>> between). Unfortunately, MachineCSE gets in the way sometimes and rips <br>> it apart.<br>> <br>> Is there a way to stop CSE from doing its thing (common subexpression <br>> elimination) for certain instructions?<br>> <br>> I've already tried glueing (gluing?) them together, but that doesn't <br>> seem to make a difference.<br>> <br>> Regards,<br>> Johannes Birgmeier<br>> _______________________________________________<br>> LLVM Developers mailing list<br>> <a
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