[Mesa-dev] [RFC 0/9] Add precise/invariant semantics to TGSI

[Karol Herbst]

Running Tomb Raider on Nouveau I found some flicker caused by ignoring precise
modifiers on variables inside Nouveau.

This series add precise/invariant handling to TGSI, which can be then used by
drivers to disable certain unsafe optimisations which may otherwise alter
calculations, which depend on having the same result across shaders.

This series fixes this bug in Tomb Raider and one CTS test for 4.4 and 4.5

Note on Patch 3: I really dislike how I tell glsl_to_tgsi_visitor to apply the
precise flag on instruction emited in ir_assignment->rhs->accept(); but I found
no other easy way to handle this. Maybe somebody of you has a better idea?

Karol Herbst (9):
  tgsi: add precise flag to tgsi_instruction
  tgsi/dump: print _PRECISE modifier on Instrutions
  st/glsl_to_tgsi: handle precise modifier
  tgsi: populate precise
  tgsi/text: parse _PRECISE modifier
  nv50/ir: add precise field to Instruction
  nv50/ir/tgsi: handle precise for most ALU instructions
  nv50/ir: disable mul+add to mad for precise instructions
  nv50/ir/tgsi: split mad to mul+add

 src/gallium/auxiliary/tgsi/tgsi_build.c            |  4 +
 src/gallium/auxiliary/tgsi/tgsi_dump.c             |  4 +
 src/gallium/auxiliary/tgsi/tgsi_text.c             | 15 +++-
 src/gallium/auxiliary/tgsi/tgsi_ureg.c             | 14 +++-
 src/gallium/auxiliary/tgsi/tgsi_ureg.h             | 20 ++++-
 src/gallium/auxiliary/util/u_simple_shaders.c      |  2 +-
 src/gallium/drivers/nouveau/codegen/nv50_ir.h      |  1 +
 .../drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp  | 16 ++++
 .../drivers/nouveau/codegen/nv50_ir_peephole.cpp   |  6 +-
 src/gallium/include/pipe/p_shader_tokens.h         |  3 +-
 src/gallium/state_trackers/nine/nine_shader.c      |  6 +-
 src/mesa/state_tracker/st_atifs_to_tgsi.c          | 38 ++++-----
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp         | 92 +++++++++++++++++-----
 src/mesa/state_tracker/st_mesa_to_tgsi.c           |  8 +-
 src/mesa/state_tracker/st_pbo.c                    |  2 +-
 15 files changed, 172 insertions(+), 59 deletions(-)

-- 
2.13.1