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?
Jakub
