Implement ir_if (for if-statments) and conversion from AST
The following tests now pass:
glslparsertest/shaders/if1.frag
glslparsertest/shaders/if2.frag
The following tests that used to pass now fail. It appears that most
of these fail because ast_nequal and ast_equal are not converted to HIR.
shaders/glsl-unused-varying.frag
shaders/glsl-fs-sqrt-branch.frag
Move swizzles out of ir_dereference and into their own class.
Also turn generate_swizzle into a static "create" method of the new
class; we'll want to use it for the IR reader as well.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
IR visitor: Add initial version of ir_visitor classes
The ir_visitor class is the abstract base class for all visitors.
ir_print_visitor contains the beginnings of a concrete visitor class
that will print out an IR sequence in a Lisp / Scheme-like syntax.
The ast_expression_bin subclass is used for all binary expressions
such as addition, subtraction, and comparisons. Several other
subclasses are soon to follow.