Re: [PATCH 20/22] x86,word-at-a-time: Remove .fixup usage

From: Peter Zijlstra
Date: Tue Nov 09 2021 - 16:07:53 EST


On Tue, Nov 09, 2021 at 11:22:44AM -0800, Nick Desaulniers wrote:

> I think the use of this feature (label-attributes) here isn't
> necessary though; because of the use of outputs, the "fallthrough"
> basic block needs to be placed immediately after the basic block
> terminated by the asm goto, at least in LLVM. Was different ordering
> of basic blocks observed with GCC without this label attribute?

GCC does the same, but I wanted to have the exception stuff be in
.text.cold, but alas it doesn't do that. I left the attribute because of
it's descriptive value.

> Unless the cold attribute is helping move
> ("shrink-wrap"?) the basic block to a whole other section
> (.text.cold.)?

I was hoping it would do that, but it doesn't on gcc-11.