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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
18392443d4 glsl/lower_clip_distance: Update symbol table.
This patch modifies the clip distance lowering pass so that the new
symbol it generates (glClipDistanceMESA) is added to the shader's
symbol table.

This will allow a later patch to modify the linker so that it finds
transform feedback varyings using the symbol table rather than having
to iterate through all the declarations in the shader.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-12-14 10:48:28 -08:00
Kenneth Graunke
82065fa20e glsl: Remove ir_call::get_callee() and set_callee().
Previously, set_callee() performed some assertions about the type of the
ir_call; protecting the bare pointer ensured these checks would be run.

However, ir_call no longer has a type, so the getter and setter methods
don't actually do anything useful.  Remove them in favor of accessing
callee directly, as is done with most other fields in our IR.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-04-02 14:15:43 -07:00
Paul Berry
c06e325967 glsl: Implement a lowering pass for gl_ClipDistance.
In i965 GEN6+ (and I suspect most other hardware), gl_ClipDistance
needs to be laid out as a pair of vec4's (the first containing clip
distances 0-3, and the second containing clip distances 4-7).
However, it is declared in GLSL as an array of 8 floats.

This lowering pass acts at the GLSL level, modifying the declaration
of gl_ClipDistance so that it is an array of vec4's rather than an
array of floats, and renaming it to gl_ClipDistanceMESA.  In addition,
it modifies all accesses to the array so that they access the
appropiate component of one of the vec4's.

Since some hardware may not internally represent gl_ClipDistance as a
pair of vec4's, this lowering pass is optional.  To enable it, set the
LowerClipDistance flag in gl_shader_compiler_options to true.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2011-09-23 13:28:43 -07:00