site_archiver@lists.apple.com Delivered-To: Darwin-dev@lists.apple.com On Dec 20, 2004, at 7:26 AM, Paolo Molaro wrote: In order to speedup access to thread local variables in the code generated by the mono JIT, I'd like to inline the code sequence directly instead of calling pthread_getspecific (). Of course I know this is risky, since the implementation could change, Dump of assembler code for function __pthread_getspecific: 0xffff82c0 <__pthread_getspecific+0>: nop 0xffff82c4 <__pthread_getspecific+4>: .long 0x0 0xffff82c8 <__pthread_getspecific+8>: .long 0x0 0xffff82cc <__pthread_getspecific+12>: .long 0x0 [...] -Eric _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... You're treading in very dangerous territory here. As you've noticed, the kernel fills out __pthread_getspecific. It does so by including the best implementation for the specific hardware in use. Short of copying out that code at app launch and using it, you're likely to end up with a worse implementation for various systems than the current code. And while copying out that code at app launch may seem tempting, even that is dangerous if the location of __pthread_getspecific changes in the future. Dump of assembler code for function pthread_getspecific: 0x90001de0 <pthread_getspecific+0>: li r4,72 0x90001de4 <pthread_getspecific+4>: ba 0xffff82c0 <__pthread_getspecific> I'm not sure how you got that output, but here's what I get when I debug Safari on my PowerBook running 10.3.6: Breakpoint 1, 0x90001de0 in pthread_getspecific () (gdb) x /2i $pc 0x90001de0 <pthread_getspecific>: li r4,72 0x90001de4 <pthread_getspecific+4>: ba 0xffff82c0 <__pthread_getspecific> (gdb) si 2 0xffff82c0 in __pthread_getspecific () (gdb) x /6i $pc 0xffff82c0 <__pthread_getspecific>: rlwinm r5,r3,2,0,29 0xffff82c4 <__pthread_getspecific+4>: li r0,32754 0xffff82c8 <__pthread_getspecific+8>: sc 0xffff82cc <__pthread_getspecific+12>: add r5,r5,r4 0xffff82d0 <__pthread_getspecific+16>: lwzx r3,r3,r5 0xffff82d4 <__pthread_getspecific+20>: blr This email sent to site_archiver@lists.apple.com