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 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
Otherwise ubsan reports errors such as:
libs/vkd3d-shader/spirv.c:7266:5: runtime error: null pointer passed as argument 1, which is declared to never be null
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
Otherwise when passing "-fsanitize=undefined" to the compiler, ubsan
reports such as:
libs/vkd3d-shader/ir.c:3794:5: 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.
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.
