Overview

Computerator is a tool to launch compute shaders, written in assembly. The main purpose is to have an easy way to experiment with instructions without dealing with the entire compiler stack (which makes controlling the order of instructions, the registers chosen, etc, difficult). The choice of compute shaders is simply because there is far less state setup required.

Headers

The shader assembly can be prefixed with headers to control state setup:

• @localsize X, Y, Z - configures local workgroup size
• @buf SZ (cN.c) - configures an SSBO of the specified size (in dwords). The order of the @buf headers determines the index, ie the first @buf header is g[0], the second g[1], and so on. The iova of the buffer is written as a vec2 to cN.c
• @const(cN.c) configures a const vec4 starting at specified const register, ie @const(c1.x) 1.0, 2.0, 3.0, 4.0 will populate c1.xyzw with vec4(1.0, 2.0, 3.0, 4.0)
• @invocationid(rN.c) will populate a vec3 starting at the specified register with the local invocation-id
• @wgid(rN.c) will populate a vec3 starting at the specified register with the workgroup-id (must be a high-reg, ie. r48.x and above)
• @numwg(cN.c) will populate a vec3 starting at the specified const register

Example

@localsize 32, 1, 1
@buf 32  ; g[0]
@const(c0.x)  0.0, 0.0, 0.0, 0.0
@const(c1.x)  1.0, 2.0, 3.0, 4.0
@wgid(r48.x)        ; r48.xyz
@invocationid(r0.x) ; r0.xyz
@numwg(c2.x)        ; c2.xyz
mov.u32u32 r0.y, r0.x
(rpt5)nop
stib.untyped.1d.u32.1 g[0] + r0.y, r0.x
end
nop

Usage

cat myshader.asm | ./computerator --disasm --groups=4,4,4