The following unary identities are applied:
||x|| -> |x|
|-x| -> |x|
~(~x) -> x
f(g(x)) -> g(x), where f(), g() are floor() or ceil() functions.
-(-x) -> x
!!x -> x
!(x == y) -> x != y, !(x < y) -> x >= y, etc (for integers).
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.
We normalize binary expressions by attempting to group constants
together, in order to facilitate further simplification of the
expressions.
For any binary operator OP, non-constants x, y, and constants a, b, we
apply the following rewrite rules:
a OP x -> x OP a, if OP is commutative.
(x OP a) OP b -> x OP (a OP b), if OP is associative.
(x OP a) OP y -> (x OP y) OP a, if OP is associative and commutative.
x OP (y OP a) -> (x OP y) OP a, if OP is associative.
Note that we consider floating point operations to be
non-associative.
This is simply unnecessary and wastes time.
As part of this, simply remove the "all" directive. Only for a couple of tests
is it even potentially interesting to validate all pixels (e.g.
nointerpolation.shader_test), and for those "all" is replaced with an explicit
(0, 0, 640, 480) rect.
In all other cases we just probe (0, 0).
The location of dxcompiler should be set during configuration with
'DXCOMPILER_LIBS=-L/path/to/dxcompiler', and then at runtime with
LD_LIBRARY_PATH, WINEPATH or PATH as applicable.
A new 'fail(sm<6)' decoration is needed on many shader declarations
because dxcompiler succeeds on many shaders which fail with fxc. The
opposite case is less common and is flagged with 'fail(sm>=6)'. A few
tests cause dxcompiler to crash or hang, so these are avoided using
[require], which now skips tests until reset instead of exiting. Also,
'todo(sm<6)' and 'todo(sm>=6)' are used to separate checking of results.
