Re: single copy atomicity for double load/stores on 32-bit systems

From: Vineet Gupta
Date: Mon Jun 03 2019 - 14:47:21 EST

On 5/31/19 1:21 AM, Peter Zijlstra wrote:
> And I'll stand by my earlier conviction that any architecture that has a
> native u64 (be it a 64bit arch or a 32bit with double-width
> instructions) but has an ABI that allows u32 alignment on them is daft.

Why ? For 64-bit data on 32-bit systems, hardware doesn't claim to provide any
single-copy atomicity for such data and software doesn't expect either.