[Mesa-dev] [PATCH 1/1] i965: Do not overwrite optimizer dumps

[Matt Turner]

On Wed, Nov 25, 2015 at 4:15 AM, Juan A. Suarez Romero
<jasuarez at igalia.com> wrote:
> When using INTEL_DEBUG=optimizer, each optimizing step is dump to disk,
> in a separate file.
>
> But as fs_visitor::optimize() and vec4_visitor::run() are called more
> than once, it ends up overwriting the files already on disk, loosing
> then previous optimizer steps.

Huh. I guess this happens when non-orthogonal state changes and we
recompile the program?

If so, yeah, that would lead to some confusing results.

> To avoid this, add a new static variable that tracks the global
> iteration across the entire life of the program running.
> ---
>  src/mesa/drivers/dri/i965/brw_fs.cpp   | 13 +++++++++----
>  src/mesa/drivers/dri/i965/brw_vec4.cpp | 11 +++++++----
>  2 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
> index 29f19cc..9520a62 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
> @@ -4947,6 +4947,8 @@ fs_visitor::calculate_register_pressure()
>  void
>  fs_visitor::optimize()
>  {
> +   static int global_iteration = 0;

I don't know that adding a static variable is the way to solve this. I
know this is debugging code, but using a static variable will make
this thread-unsafe, and I *really* don't want to end up in a situation
where I can't figure out what the optimizer is doing because we were
compiling shaders in parallel...

Ken, any ideas?