So I've made a breakthrough. The memory corruption is due to both parts of the CMOV optimization under OptPass2Jcc, not my Jcc addition (although it might have unintentionally accentuated it). The first part sets p to a dangling pointer, while the 2nd part is a little more complicated, but I'll try to spell everything out once I finish testing my new patch and see if I've eliminated all of my crashes
Gareth On Fri 29/06/18 10:05 , "J. Gareth Moreton" gar...@moreton-family.com sent: It turns out that it's invalid memory. Trying to call "ClassName" raises an access violation (other aligns work fine). There's a dangling pointer somewhere. I found one in the CMOV optimisation code, but that hasn't fixed the crash. Gareth On Fri 29/06/18 10:27 , Martok list...@martoks-place.de sent: > A clue that leads me to believe there's internal corruption is that a produced > .s file yields an alignment field of ".balign 119,0x90", which should never > happen. Could you set a breakpoint on aggas.pas:721 (the call to doalign) with a conditional on "tai_align_abstract(hp).aligntype=119" and check what the actual type of hp is? It could be that at some point a node gets its typ changed in an invalid way? aligntype should be either one of 2^[0..5], never something else... This is where AddressSanitizer support would be *nice*. -- Regards, Martok Ceterum censeo b32079 esse sanandam. _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org [1] http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel [2]">http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org [3] http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel [4]">http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel Links: ------ [1] mailto:fpc-devel@lists.freepascal.org [2] http://secureweb.fast.net.uk/ http:= [3] mailto:fpc-devel@lists.freepascal.org [4] http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
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