Re: [PATCH] drm/amdgpu: Re-enable DCN for 64-bit powerpc

----- Original Message -----

From: "Linus Torvalds" <torvalds@linux-foundation.org>
To: "Michael Ellerman" <mpe@ellerman.id.au>
Cc: "linuxppc-dev" <redacted>, "Alex Deucher" <redacted>, "amd-gfx"
[off-list ref], linux@roeck-us.net, "linux-kernel" [off-list ref], "Dan Horák"
[off-list ref], "Timothy Pearson" [off-list ref]
Sent: Monday, July 25, 2022 2:19:57 PM
Subject: Re: [PATCH] drm/amdgpu: Re-enable DCN for 64-bit powerpc

On Mon, Jul 25, 2022 at 5:39 AM Michael Ellerman [off-list ref] wrote:

quoted

Further digging shows that the build failures only occur with compilers
that default to 64-bit long double.

Where the heck do we have 'long double' things anywhere in the kernel?

I tried to grep for it, and failed miserably. I found some constants
that would qualify, but they were in the v4l colorspaces-details.rst
doc file.

Strange.

We don't, at least not that I can see.  The affected code uses standard doubles.

What I'm wondering is if the compiler is getting confused between standard and long doubles when they are both the same bit length...