While so far it has been posible to do this at parse time, this must
happen after knowing if the complex cast is on the lhs or not.
The modified tests show that before this patch we are currently
miscompiling when this happens, because a complex lhs cast is transformed
into a load, and add_assigment() just stores to the generated "cast"
temp.
Vertex shaders do not have CMP, so we use SLT and MAD.
For example, this vertex shader:
uniform float4 f;
void main(inout float4 pos : position, out float4 t1 : TEXCOORD1)
{
t1 = (int4)f;
}
results in:
vs_2_0
dcl_position v0
slt r0, c0, -c0
frc r1, c0
add r2, -r1, c0
slt r1, -r1, r1
mad oT1, r0, r1, r2
mov oPos, v0
while we have the lower_cmp() pass, each time it is applied many
instructions are generated, so this patch introduces a specialized
version of the cast-to-int lowering for efficiency.
Otherwise ubsan reports runtime errors such as:
libs/vkd3d-shader/ir.c:4731:5: runtime error: null pointer passed as argument 1, which is declared to never be null
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.
