The following conditional identities are applied:
c ? x : x -> x
false ? x : y -> y; true ? x : y -> x
c ? true : false -> c; c ? false : true -> !c
!c ? x : y -> c ? y : x
Lastly, for expression chains x, y in a conditional expression
c ? x : y,
we evaluate all conditionals in the expression chains with the
condition c, assuming c is true (for x), or false (for y).
Otherwise ubsan reports these errors on the bitwise.shader_test:
libs/vkd3d-shader/hlsl_constant_ops.c:970:50: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'
libs/vkd3d-shader/hlsl_constant_ops.c:970:50: runtime error: left shift of negative value -12
Since we have -Wswitch, this forces the developer to update all relevant
switches when an enum case is added.
Places where the default is just a FIXME are left alone.
We apply distributivity to applicable expressions, specifically with
the following rewrite rules:
(x OPL a) OPR (x OPL b) -> x OPL (a OPR b)
(y OPR (x OPL a)) OPR (x OPL b) -> y OPR (x OPL (a OPR b))
((x OPL a) OPR y) OPR (x OPL b) -> (x OPL (a OPR b)) OPR y
(x OPL a) OPR ((x OPL b) OPR y) -> (x OPL (a OPR b)) OPR y
(x OPL a) OPR (y OPR (x OPL b)) -> (x OPL (a OPR b)) OPR y
where a, b are constants.
