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Author SHA1 Message Date
Paul Berry
42a29d89fd glsl: Eliminate ambiguity between function ins/outs and shader ins/outs
This patch replaces the three ir_variable_mode enums:

- ir_var_in
- ir_var_out
- ir_var_inout

with the following five:

- ir_var_shader_in
- ir_var_shader_out
- ir_var_function_in
- ir_var_function_out
- ir_var_function_inout

This eliminates a frustrating ambiguity: it used to be impossible to
tell whether an ir_var_{in,out} variable was a shader in/out or a
function in/out without seeing where the variable was declared in the
IR.  This complicated some optimization and lowering passes, and would
have become a problem for implementing varying structs.

In the lisp-style serialization of GLSL IR to strings performed by
ir_print_visitor.cpp and ir_reader.cpp, I've retained the names "in",
"out", and "inout" for function parameters, to avoid introducing code
churn to the src/glsl/builtins/ir/ directory.

Note: a couple of comments in the code seemed to indicate that we were
planning for a possible future in which geometry shaders could have
shader-scope inout variables.  Our GLSL grammar rejects shader-scope
inout variables, and I've been unable to find any evidence in the GLSL
standards documents (or extensions) that this will ever be allowed, so
I've eliminated these comments.

Reviewed-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2013-01-24 16:30:30 -08:00
Paul Berry
c35abcd1b0 glsl: Pack flat "varyings" of mixed types together.
This patch enhances the varying packing code so that flat varyings of
uint, int, and float types can be packed together.

We accomplish this in lower_packed_varyings.cpp by making the type of
all flat varyings ivec4, and then using information-preserving type
conversions (e.g. ir_unop_bitcast_f2i) to convert all other types to
ints.

The varying_matches::compute_packing_class() function is updated to
reflect the fact that varying packing no longer needs to segregate
varyings of different base types.

Fixes piglit test varying-packing-mixed-types.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

v2: Split lower_packed_varyings_visitor::bitwise_assign into
pack/unpack variants.
2013-01-08 09:18:14 -08:00
Paul Berry
4b11b57ab4 glsl: Separate varying linking code to its own file.
linker.cpp is getting pretty big, and we're about to add even more
varying packing code, so split out the linker code that concerns
varyings to its own file.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-08 09:09:09 -08:00