% Test implicit and explicit casts on function output parameters. [pixel shader todo] uniform float4 f; void func(out float4 o) { o = f; } float4 main() : sv_target { int4 x; func(x); return x; } [test] uniform 0 float4 -1.9 -1.0 2.9 4.0 todo(sm<6) draw quad probe (0, 0) rgba (-1.0, -1.0, 2.0, 4.0) % As above, but cast "x" to float4 first. % In SM 6 a cast seems to implicitly promote the type to const, % so it fails to match the parameter of func(). [pixel shader todo fail(sm>=6)] uniform float4 f; void func(out float4 o) { o = f; } float4 main() : sv_target { int4 x; func((float4)x); return x; } [test] uniform 0 float4 -1.9 -1.0 2.9 4.0 todo draw quad probe (0, 0) rgba (-1.0, -1.0, 2.0, 4.0) % As above, but declare "x" as float4 and cast it to int4. [pixel shader todo fail(sm>=6)] uniform float4 f; void func(out float4 o) { o = f; } float4 main() : sv_target { float4 x; func((int4)x); return x; } [test] uniform 0 float4 -1.9 -1.0 2.9 4.0 todo draw quad probe (0, 0) rgba (-1.0, -1.0, 2.0, 4.0) [pixel shader todo] uniform int4 i; void func(inout float4 a) { a += 0.1; } float4 main() : sv_target { int4 x = i; func(x); return x; } [test] if(sm<4) uniform 0 float4 -2 0 1 -3000000 if(sm>=4) uniform 0 int4 -2 0 1 -3000000 todo(sm<6) draw quad probe (0, 0) rgba (-1.0, 0.0, 1.0, -3000000.0) 4