Skip to content

vkd3d-shader/hlsl: Reinterpret minimum precision types as their regular counterparts.

Francisco Casas requested to merge fcasas/vkd3d:minimum_prec into master

Reinterpret min16float, min10float, min16int, min12int, and min16uint as their regular counterparts: float, float, int, int, uint, respectively.

A proper implementation would require adding minimum precision indicators to all the dxbc-tpf instructions that use these types. Consider the output of fxc 10.1 with the following shader:

uniform int i;

float4 main() : sv_target
{
    min16float4 a = {0, 1, 2, i};
    min16int2 b = {4, i};
    min10float3 c = {6.4, 7, i};
    min12int d = 9.4;
    min16uint4x2 e = {14.4, 15, 16, 17, 18, 19, 20, i};

    return mul(e, b) + a + c.xyzx + d;
}
ps_5_0
dcl_globalFlags refactoringAllowed | enableMinimumPrecision
dcl_constantbuffer CB0[1], immediateIndexed
dcl_output o0.xyzw
dcl_temps 3
imad r0.xyz {min16u}, l(15, 17, 19, 0) {def32 as min16u}, cb0[0].xxxx {def32 as min16u}, l(56, 64, 72, 0) {def32 as min16u}
utof r0.xyz {min16f}, r0.xyzx {min16u}
imad r1.x {min16u}, cb0[0].x {def32 as min16u}, cb0[0].x {def32 as min16u}, l(80) {def32 as min16u}
utof r0.w {min16f}, r1.x {min16u}
mov r1.xyz {min16f}, l(0,1.000000,2.000000,0) {def32 as min16f}
itof r1.w {min16f}, cb0[0].x
add r0.xyzw {min16f}, r0.xyzw {min16f}, r1.xyzw {min16f}
mov r2.y {min2_8f}, l(7.000000) {def32 as min2_8f}
itof r2.z {min2_8f}, cb0[0].x
add r0.yz {min16f}, r0.yyzy {min16f}, r2.yyzy {min2_8f as min16f}
add r0.xyzw {min16f}, r0.xyzw {min16f}, l(15.400000, 9.000000, 9.000000, 15.400000) {def32 as min16f}
mov o0.xyzw, r0.xyzw {min16f as def32}
ret

However, if the graphics driver doesn't have minimum precision support, it ignores the minimum precision indicators and runs at 32-bit precision, which is equivalent as working with regular types.

Merge request reports