[Bug 7901] ShaderStudio: rcp instruction works incorrectly in vertex shaders 1.1/wine 0.9.33

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=7901

------- Additional Comments From [e-mail]  2007-31-03 08:32 -------
> Is this with ARB or GLSL shaders?

Wine currently uses ARB shaders.
> If I read the sdk description of rcp correctly, those source swizzles are 
> incorrect. r0.x, r0.y, r0.z, r0.w are each allowed, r0 is the same as r0.x, 
> but things like r0.xy r0.xz, r0.wz, r0.xyz, etc are not allowed. Are you sure 
> that these shaders work correctly in windows? With which drivers did you test 
> on windows?

The shader was originally written for ATI Radeon 9100/Catalyst 3.6..3.9(don't 
know exact version). I don't have access to that hardware anymore and can't be 
absolutely sure that this hardware actually swapped sources and used different 
channels.

However, I've just tried same shader on my current Windows configuration: WinXP 
SP2/GeForce FX 7100 GS/ForceWare 93.71.
I've got some interesting results:
1) On Windows including rcp instruction with source mask doesn't kill shader.  
On Wine All graphic output from that shader disappears immediatly when rcp 
instruction with source mask is placed somewhere inside vertex shader. Even if 
result of instruction is not used.
2) On both platforms (Wine/WinXP) shader compiles with no errors/no error 
messages, even if source mask is present. (It looks like Shader Studio uses 
D3DXAssembleShader)
3) On Windows rcp instruction source mask DOESN'T work, but behave in 
undocumented way. If any source mask is given, rcp instruction uses last given 
channel as an argument. I.e. "rcp r0.xy, r0.xy" works as "rcp r0.xy, r0.y", 
"rcp r0.xyz, r0.yxz" works as "rcp r0.xyz, r0.z". You can test that yourself, 
by defining some constants in shader and using rcp result to multiply texture 
coordinates. For example, like this:
def c0, 0.5, 1.0, 2.0, 4.0
mad r0.xy, v7.xy, c0.zz, -c0.yy
mov oPos.x, r0.x
mov oPos.y, -r0.y
mov oPos.z, c0.x
mov oPos.w, c0.y
rcp r0.xy, c0.xy
;rcp r0.xy, c0.yx
mul oT0.xy, r0, v0

On my system texture on resulting picture have same tiling in U and V 
directions, as if only last source channel was given in rcp source mask.