[Mesa-dev] [RFC] optimise st_glsl_to_tgsi

[Dave Airlie]

I profiled shader-db running on radeonsi, and the temp register
handling passes in the glsl->tgsi convertor were quite heavy
users of CPU.

These two passes are my attempt at cleaning them up to avoid
looping over the instruction set so much. I'm in the process
of piglitting then,

On my CPU, a shader-db in one thread takes about 24s before
this and about 21s after, and glsl_to_tgsi_visitor goes
down the profile list.

Dave.