[Mesa-dev] [PATCH 00/15] nir: Rework boolean (and maybe all?) conversions

[Jason Ekstrand]

Welcome to this choose-your-own-adventure patch series!  The first six
patches are good-to-go regardless of choices made later.  However, starting
with patch 7, we have a choice to make.

Version A of this series reworks NIR conversion opcodes to not have sizes
and instead simply accept any source and destination size regardless of
whether or not they match.  This is something that Connor and I talked
about some time ago when we were first adding bit sizes.  With most
opcodes, if they have any variable-size sources or a variable size
destination, all variable sized things must match.  This series changes the
rules so that, for conversion ops, they have a variable size source and
destination which DO NOT have to match.  The upside to this is that we get
to throw away piles of opcodes.  The downside is that it makes a number of
things: validation, nir_search, constant folding, etc. more complicated
because they now have to deal with a new set of rules.

Version B of the series, reworks boolean conversions to be like the current
conversions and also have bit sizes.  Unfortunately, this makes hash of
opt_algebraic because, thanks to some applications love of re-inventing
Boolean operations, we have piles of optimizations that contain b2f, f2b,
b2i and i2b.  To deal with that problem (and make opt_algebraic easier to
use in general), version B adds virtual unsized conversion opcodes to
nir_search so that you can make an expression that matches any i2f opcode
regardless of size.  From the perspective of opt_algebraic, then, the two
series are nearly identical.  The downside of this approach is that the
nir_search changes are kind-of hacky and we still have piles of conversion
opcodes.  The upside, however, is that we don't have the extra mental
overhead in constant folding, validation, and elsewhere of having this
opcode special-case.

What is the fate of NIR?  That's up to the people to decide!

Cc: Ian Romanick <ian.d.romanick at intel.com>
Cc: Connor Abbott <cwabbott0 at gmail.com>

Jason Ekstrand COMMON (6):
  nir/opcodes: Pull in the type helpers from constant_expressions
  nir/opcodes: Rename tbool to tbool32
  nir/algebraic: Improve a couple error messages
  nir/algebraic: Set variable classes to the explicit bit size
  nir/algebraic: Clean up some __str__ cruft
  nir/algebraic: Improve error messages for replace expressions

Jason Ekstrand VERSION A (9):
  nir: Add a concept of an unsized conversion opcode
  nir/builder: Create sized helpers for unsized conversion opcodes
  nir/constant_expressions: Handle unsized conversion ops
  nir/algebraic: Add support for unsized conversion opcodes
  nir: Switch conversions to unsized opcodes
  FIXUP: Fix NIR producers and consumers to use unsized conversions
  FIXUP: nir/opt_algebraic: Drop bit-size suffixes from conversions
  nir/algebraic: Add 32-bit specifiers to a bunch of booleans
  nir: Make boolean conversions unsized like other types

Jason Ekstrand VERSION B (8):
  nir/algebraic: Refactor codegen a bit
  nir/algebraic: Add support for unsized conversion opcodes
  nir/opt_algebraic: Simplify an optimization using the new search ops
  nir/opt_algebraic: Drop bit-size suffixes from conversions
  nir/opt_algebraic: Add 32-bit specifiers to a bunch of booleans
  nir: Make boolean conversions sized just like the others
  FIXUP: nir/opt_algebraic: Add suffixes to some x2b opcodes
  FIXUP: Fix NIR producers and consumers to use unsized conversions

 src/amd/common/ac_nir_to_llvm.c               |  32 +--
 src/compiler/glsl/glsl_to_nir.cpp             |   2 +-
 src/compiler/nir/nir.c                        |  67 ++++++
 src/compiler/nir/nir.h                        |   7 +
 src/compiler/nir/nir_algebraic.py             | 174 +++++++++++----
 src/compiler/nir/nir_builder.h                |  30 ++-
 src/compiler/nir/nir_builder_opcodes_h.py     |  16 +-
 src/compiler/nir/nir_constant_expressions.h   |   3 +-
 src/compiler/nir/nir_constant_expressions.py  |  59 +++---
 src/compiler/nir/nir_loop_analyze.c           |   7 +-
 src/compiler/nir/nir_lower_idiv.c             |   2 +-
 src/compiler/nir/nir_lower_int64.c            |   2 +-
 src/compiler/nir/nir_opcodes.py               | 152 +++++++------
 src/compiler/nir/nir_opcodes_c.py             |  89 +-------
 src/compiler/nir/nir_opt_algebraic.py         | 199 +++++++++---------
 src/compiler/nir/nir_opt_constant_folding.c   |   5 +-
 src/compiler/nir/nir_search.c                 |  19 +-
 src/compiler/nir/nir_validate.c               |   4 +
 src/compiler/spirv/spirv_to_nir.c             |   3 +-
 src/compiler/spirv/vtn_glsl450.c              |   4 +-
 src/gallium/auxiliary/nir/tgsi_to_nir.c       |   8 +-
 .../drivers/freedreno/ir3/ir3_compiler_nir.c  | 148 ++++++-------
 src/gallium/drivers/vc4/vc4_program.c         |   8 +-
 src/intel/compiler/brw_fs_nir.cpp             |  78 +++----
 src/intel/compiler/brw_vec4_nir.cpp           |  39 ++--
 src/mesa/program/prog_to_nir.c                |   4 +-
 26 files changed, 626 insertions(+), 535 deletions(-)

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2.19.1