Wow, thank you all, you guys! 在 2024年3月14日星期四，Jonathan Wakely <jwak...@redhat.com> 写道：
> On Fri, 16 Feb 2024 at 15:15, Jonathan Wakely wrote: > > > > On Fri, 16 Feb 2024 at 14:10, Jakub Jelinek wrote: > > > > > > On Fri, Feb 16, 2024 at 01:51:54PM +0000, Jonathan Wakely wrote: > > > > Ah, although __atomic_compare_exchange only takes pointers, the > > > > compiler replaces that with a call to __atomic_compare_exchange_n > > > > which takes the newval by value, which presumably uses an 80-bit FP > > > > register and so the padding bits become indeterminate again. > > > > > > __atomic_compare_exchange_n only works with integers, so I guess > > > it is doing VIEW_CONVERT_EXPR (aka union-style type punning) on the > > > argument. > > > > > > Do you have preprocessed source for the testcase? > > > > Sent offlist. > > Jakub fixed the compiler, so I've pushed the attached patch now. > > Tested x86_64-linux. >
