Re: [PATCH] powerpc: workaround clang codegen bug in dcbz

On Mon, Jul 29, 2019 at 01:32:46PM -0700, Nathan Chancellor wrote:

For the record:

https://godbolt.org/z/z57VU7

This seems consistent with what Michael found so I don't think a revert
is entirely unreasonable.

Try this:

  https://godbolt.org/z/6_ZfVi

This matters in non-trivial loops, for example.  But all current cases
where such non-trivial loops are done with cache block instructions are
actually written in real assembler already, using two registers.
Because performance matters.  Not that I recommend writing code as
critical as memset in C with inline asm :-)


Segher