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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi Lang,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>While working on improving the debug dumps of the PBQP graphs, I found out that we can have some edges between nodes which belong to totally disjoint register classes (for example, on AArch64, this would be an int and a floating point register). Although it is true those 2 registers interferes, in the sense they are alive at the same time, they never have any physical interference, and this shows up as a zero matrix.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I was wondering if it could make sense to skip adding such edges to the graph, as they do not add useful information, they increases the nodes degrees … and ultimately make the allocation take longer time.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have a patch ready prototyping this. It unfortunately breaks with the last fix you made (@ r227942), but if I revert it, it just works fine. if you believe this could be worth it, then I will investigate where the failure comes from.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Cheers,<o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>--<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>Arnaud A. de Grandmaison<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>