This is an invasive set of changes. Each user shader tracks a set of other
shaders that contain built-in functions. During compilation, function
prototypes are imported from these shaders. During linking, the
shaders are linked with these built-in-function shaders just like with
any other shader.
This is quite a large patch because breaking it into smaller pieces
would result in the tree being intermitently broken. The big changes
are:
* Add the ir_var_temporary variable mode
* Change the ir_variable constructor to take the mode as a
parameter and correctly specify the mode for all ir_varables.
* Change the linker to not cross validate ir_var_temporary
variables.
* Change the linker to pull all ir_var_temporary variables from
global scope into 'main'.
The constant_expression_wrapper was already the only external API, and
much of the internal code used it anyway. Also, it wouldn't ever visit
non-rvalue ir_instructions, so using a visitor seemed a bit unnecessary.
This uses "ir_foo *ir = this;" lines to avoid code churn. These should
be removed.
Give ir_function::parameter_lists_match_exist similar treatment. Make
the parameters const, and propogate the constness as far as it will
trivially go.
This is a big deal for debugging if nothing else ("what class is this
ir_instruction, really?"), but is also nice for avoiding building a
whole visitor or an if (node->as_whatever() || node->as_other_thing())
chain.
The linker needs to use this function to get specific function signatures, but
it also needs to modify the returned signature. Since this method isn't itself
const (i.e., const this pointer), there is no value in making a const and
non-const version.
This currently involves an ugly hack so that every link doesn't result
in all the built-in functions showing up as multiply defined. As soon
as the built-in functions are stored in a separate compilation unit,
ir_function_signature::is_built_in can be removed.
There is no setter function, the getter returns a constant pointer,
and ir_function_signature::_function is private for a reason. The
only way to make a connection between a function and function
signature is via ir_function::add_signature. This helps ensure that
certain invariants (i.e., a function signature is in the list of
signatures for its _function) are met.
This will be used by the Mesa IR and likely most HW backends, as it
allows other optimizations to occur that might not otherwise.
Fixes glsl-vs-mat-sub-1, glsl-vs-mat-div-1.
