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</o:shapelayout></xml><![endif]--></head><body lang=ZH-CN link="#0563C1" vlink="#954F72" style='text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hi List,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Although I submitted a patch recently to set the barrier function to noduplicate attribute, but it seems that it still has problem.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Considering the following type of code:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Label0:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> call barrier;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Label1:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> …<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> br i1 %cmp0, label %label2, %label0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>label2:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> …<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> …<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> br label0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Actually, on the end of label1 BB, the function call barrier is duplicate on both the if and else branches from the CF view.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>As we are using prediction, and we compare 16 channels on the same time, if some channels goto the if.then branch and<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>the others goto the if.else branch, then the barrier will be called twice. But if on the other thread, all the channels are going<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>into one branch, then the barrier will be called only once. Then we will hang at the first thread’s second call to barrier.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I don’t have a very good idea currently. One idea come to my mind is to make a joint of the if.then and the if.else branches,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Then at the joint point, we jump to the BB which hold the barrier function call unconditionally. Then we can gurantte that the<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>barrier will be called only once. The side effect of this solution is that it introduce one more jump instruction. Any other idea?<o:p></o:p></span></p></div></body></html>