cygwin readers: This is about porting java to cygwin for gcc-3.2 (and perhaps gcc-3.1.1 if the changes are small).
So we need objects to be 8-byte aligned so that the low three bits of the address are 0? Are there any ways around this, as I don't think that this is the default on cygwin. I seem to recall that: - objects are only 4-byte aligned by default. - it is necessary to rebuild ld to ensure 8-byte alignment - there are performance benefits for 8-byte (or even 16-byte) alignment, but arguements against. There is much discussion over a long period in the cygwin archives, which I will obviously have to re-read in the next little while. -----Original Message----- From: Tom Tromey [mailto:[EMAIL PROTECTED]] Sent: Saturday, 4 May 2002 6:31 To: Billinghurst, David (CRTS) Cc: [EMAIL PROTECTED] Subject: Re: cygwin failures - assertion "!(addr & FLAGS)" failed: >>>>> "David" == Billinghurst, David (CRTS) <[EMAIL PROTECTED]> writes: David> At last a real bug in the cygwin libjava testsuite. Most of the David> compilation tests pass, but all (that I could find) executable David> tests fail with David> assertion "!(addr & FLAGS)" failed: file "/usr/local/src/gcc3.1/libjava/java/lang/natObject.cc", line 772 My understanding is that we use the lowest 3 bits to keep some information about the thin locks. If this assertion fails, it means that we've found an object which isn't suitably aligned. I think this can mean one of two things: 1. There is a bug in the allocator (unlikely), or 2. The compiler isn't properly aligning an object which it lays out statically. For instance this could happen with some Class object A bug along these lines was fixed pretty recently: 2002-04-18 Bryce McKinlay <[EMAIL PROTECTED]> * class.c (make_class_data): Set DECL_ALIGN on static class data, for hash synchronization. * expr.c (java_expand_expr): Set DECL_ALIGN on static array objects. * decl.c (java_init_decl_processing): Don't set TYPE_ALIGN for class_type_node. If you already have this patch then I guess there's another such bug :-( Tom -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
