<div dir="ltr">Hmm,<div><br></div><div>compiling your test I've noticed that even before entering the SwitchToSelect optimization the PHI that breaks the module already has two incoming edges for the same predecessor:</div><div><br></div><div>This is the IR just entering SwitchToSelect:</div><div><br></div><div><p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">; Function Attrs: nounwind ssp uwtable</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">define i32 @fn1() #0 {</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">entry:</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> %0 = load i32* @b, align 4</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> %tobool = icmp eq i32 %0, 0</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> br i1 %tobool, label %if.end3, label %if.then</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40);min-height:13px"><br></p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">if.then: ; preds = %entry</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> %1 = load i32* @a, align 4</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> switch i32 %1, label %if.end3 [</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> i32 5, label %return</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> i32 0, label %return</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> ]</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40);min-height:13px"><br></p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">if.end3: ; preds = %if.then, %entry</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> br label %return</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40);min-height:13px"><br></p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">return: ; preds = %if.then, %if.then, %if.end3</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> %retval.0 = phi i32 [ 0, %if.end3 ], [ %1, %if.then ], [ %1, %if.then ]</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)"> ret i32 %retval.0</p>
<p style="margin:0px;font-size:11px;font-family:Menlo;color:rgb(215,201,167);background-color:rgb(142,53,40)">}</p></div><div><br></div><div>Is this condition expected to be handled by the switch lowering? Or is the switch formation that probably introduced this malformed?</div><div>Is pretty easily to workaround this in SwitchToSelect to reiterate Incoming Edge deletion when the switch is removed until no more edges from the same predecessor are found, but I guess if we have some other issue more up in the pipeline.</div></div><div class="gmail_extra"><br><div class="gmail_quote">2014-10-12 14:35 GMT-07:00 Marcello Maggioni <span dir="ltr"><<a href="mailto:hayarms@gmail.com" target="_blank">hayarms@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thanks again Joerg, I missed the attachment!<div><br></div><div>Marcello</div></div><div class="gmail_extra"><br><div class="gmail_quote">2014-10-12 13:50 GMT-07:00 Joerg Sonnenberger <span dir="ltr"><<a href="mailto:joerg@britannica.bec.de" target="_blank">joerg@britannica.bec.de</a>></span>:<div><div class="h5"><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span>On Sun, Oct 12, 2014 at 01:09:25PM -0700, Marcello Maggioni wrote:<br>
> Thanks Joerg for reverting and thanks Jiangning for reporting the problem.<br>
><br>
> Would it be possible to have the snippet of the code that is causing the<br>
> issue or is it not publicly available? In order to be able to debug this<br>
> more effectively and safely.<br>
<br>
</span>See my earlier post in this thread for a test case.<br>
<span><font color="#888888"><br>
Joerg<br>
</font></span></blockquote></div></div></div><br></div>
</blockquote></div><br></div>