Re: [PATCH v3 1/3] x86/fpu: Make XCR0 accessors immune to unwanted compiler reordering

[Dave Hansen]

On 3/24/22 19:22, Chang S. Bae wrote:
> Some old GCC versions (4.9.x and 5.x) have an issue that incorrectly
> reordering volatile asm statements with each other [1]. While this bug was
> fixed on later versions (8.1, 7.3, and 6.5), and the kernel's current XCR0
> read/write do not appear to be impacted, it is preventive to ensure them on
> the program order.

I thought you *actually* saw xgetbv() be reordered, though.  Was that on
a buggy compiler?