[Mesa-dev] [PATCH v6 0/6] mesa/st: glsl_to_tgsi: improved temp-reg lifetime estimation

[Gert Wollny]

Dear Nicolai, 

this new version of the patch set that should address all the comments you gave 
for v5.

Changes are: 

- the components are now tracked individually and the life time of a temporary 
  is evaluated by merging the life-times of their components, 
- BRK/CONT are now handled differently, 
- the final algorithm to evaluate the life-times was simplified, 
- read and write in the same instruction is now considered to be always 
  well defined
- adherence to the coding stile was improved, 
- the case scope level is now below the according switch scope level, 
- the new register merge method replaces the old version, i.e. no environment 
  variables to switch between implementations. In theory, one could also remove 
  the function get_last_temp_read_first_temp_write, but is is still used in 
  some code in a #define 0 block, so I didn't touch it.  

In addition to your comments I applied these changes: 

- when compiled in debug mode and with the environment variable 
  GLSL_TO_TGSI_RENAME_DEBUG specified the TGSI and resulting register 
  lifetimes will be dumped to stderr.
- unused registers are now ignored in the rename mapping evaluation
- registers that are only read get a life-time {x,x}, with x the instruction 
  line were the register is last read, so they can be merged.
- the patch has been rebased against 7d7bcd65d (Date: Fri Jun 30 10:39:53 2017)

The patches are also in  
  https://github.com/gerddie/mesa/tree/regrename-v6

Additional notes: 
* According to a user report against v5, the patch fixes #99349
* The new register merge code doesn't have a measurable effect on the all-over 
  run-time of the shader-db.
* There is actually not a single shader in the shader-db that requires 
  per-component tracking of the temporaries, but I achieved writing a shader 
  that really needs it and I think I will submit this to piglit.

best regards, 
Gert


Gert Wollny (6):
  mesa/st: glsl_to_tgsi move some helper classes to extra files
  mesa/st: glsl_to_tgsi: implement new temporary register lifetime
    tracker
  mesa/st: glsl_to_tgsi: add tests for the new temporary lifetime
    tracker
  mesa/st: glsl_to_tgsi: add register rename mapping evaluator
  mesa/st: glsl_to_tgsi: Add test set for evaluation of rename mapping
  mesa/st: glsl_to_tgsi: tie in new temporary register merge approach

 configure.ac                                       |    1 +
 src/mesa/Makefile.am                               |    2 +-
 src/mesa/Makefile.sources                          |    4 +
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp         |  344 +----
 src/mesa/state_tracker/st_glsl_to_tgsi_private.cpp |  196 +++
 src/mesa/state_tracker/st_glsl_to_tgsi_private.h   |  167 +++
 .../state_tracker/st_glsl_to_tgsi_temprename.cpp   | 1066 ++++++++++++++
 .../state_tracker/st_glsl_to_tgsi_temprename.h     |   67 +
 src/mesa/state_tracker/tests/Makefile.am           |   36 +
 .../tests/test_glsl_to_tgsi_lifetime.cpp           | 1556 ++++++++++++++++++++
 10 files changed, 3106 insertions(+), 333 deletions(-)
 create mode 100644 src/mesa/state_tracker/st_glsl_to_tgsi_private.cpp
 create mode 100644 src/mesa/state_tracker/st_glsl_to_tgsi_private.h
 create mode 100644 src/mesa/state_tracker/st_glsl_to_tgsi_temprename.cpp
 create mode 100644 src/mesa/state_tracker/st_glsl_to_tgsi_temprename.h
 create mode 100644 src/mesa/state_tracker/tests/Makefile.am
 create mode 100644 src/mesa/state_tracker/tests/test_glsl_to_tgsi_lifetime.cpp

-- 
2.13.0