Commit graph

4 commits

Author SHA1 Message Date
Jason Ekstrand
dd74369a0a nir/opcodes: Don't go through doubles when constant-folding iabs
Previously, we called the abs() function in math.h.  However, this involves
unnecessarily going through double.  This commit changes it to use integers
directly with a ternary.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2015-01-26 11:25:02 -08:00
Jason Ekstrand
9bd28fe3a3 nir/opcodes: Simplify and fix the unpack_half_*_split_* constant expressions
Previously, these functions were explicitly writing to dst.x and dst.y.
However they both return only one component so writing to dst.y is invalid.
Also, since they only return one component, we don't need the explicit
assignment in the expression and can simplify it use an implicit
assignment.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
2015-01-26 11:25:02 -08:00
Jason Ekstrand
89285e4d47 nir: add new constant folding infrastructure
Add a required field to the Opcode class, const_expr, that contains an
expression or statement that computes the result of the opcode given known
constant inputs. Then take those const_expr's and expand them into a function
that takes an opcode and an array of constant inputs and spits out the constant
result. This means that when adding opcodes, there's one less place to update,
and almost all the opcodes are self-documenting since the information on how to
compute the result is right next to the definition.

The helper functions in nir_constant_expressions.c were taken from
ir_constant_expressions.cpp.

v3 Jason Ekstrand <jason.ekstrand@iastate.edu>
 - Use mako to generate one function per opcode instead of doing piles of
   string splicing

v4 Jason Ekstrand <jason.ekstrand@iastate.edu>
 - More comments and better indentation in the mako
 - Add a description of the constant expression language in nir_opcodes.py
 - Added nir_constant_expressions.py to EXTRA_DIST in Makefile.am

Signed-off-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
2015-01-24 21:35:35 -08:00
Connor Abbott
fa4bc6c130 nir: use Python to autogenerate opcode information
Before, we used a system where a file, nir_opcodes.h, defined some macros that
were included to generate the enum values and the nir_op_infos structure. This
worked pretty well, but for development the error messages were never very
useful, Python tools couldn't understand the opcode list, and it was difficult
to use nir_opcodes.h to do other things like autogenerate a builder API. Now, we
store opcode information in nir_opcodes.py, and we have nir_opcodes_c.py to
generate the old nir_opcodes.c and nir_opcodes_h.py to generate nir_opcodes.h,
which contains all the enum names and gets included into nir.h like before.  In
addition to solving the above problems, using Python and Mako to generate
everything means that it's much easier to add keep information centralized as we
add new things like constant propagation that require per-opcode information.

v2:
 - make Opcode derive from object (Dylan)
 - don't use assert like it's a function (Dylan)
 - style fixes for fnoise, use xrange (Dylan)
 - use iterkeys() in nir_opcodes_h.py (Dylan)
 - use pydoc-style comments (Jason)
 - don't make fmin/fmax commutative and associative yet (Jason)

Signed-off-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>

v3 Jason Ekstrand <jason.ekstrand@intel.com>
 - Alphabetize source file lists
 - Generate nir_opcodes.h in the builddir instead of the source dir
 - Include $(builddir)/src/glsl/nir in the i965 build
 - Rework nir_opcodes.h generation so it generates a complete header file
   instead of one that has to be embedded inside an enum declaration
2015-01-24 21:33:56 -08:00