2013/7/30 Rico Schüller kgbricola@web.de:
Hi Matteo,
please see the attached patch.
On 25.07.2013 16:13, Matteo Bruni wrote:
2013/7/24 Rico Schüller kgbricola@web.de:
dlls/d3dx9_36/tests/shader.c | 308 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 308 insertions(+)
This is okay, but as a followup can you add some tests with mixed-type structs? Something like:
struct { float f; int i; bool b; };
If you have already written tests of this kind, I'd like to know what does the compiler do in this case :)
Single variables could only have the tested types (I was not able to generate other conversions than bool->bool, int->int, int->float, bool->float, float->float). But I found a way to do it with structs and there I found some issues. Hence this has to be fixed in wine, too. Thanks for the nice question. :-)
Basically you got these for the struct:
- D3DXRS_FLOAT4: if one variable is used as float or a float variable is
used or an int variable is used as bool (the compiler may do some optimization), else #2 2. D3DXRS_BOOL: if a bool variable is used as bool (in an if clause), else #3 3. D3DXRS_INT4
It looks like you could only do it that way with unused variables. I'm not sure if this makes sense at all. Why would someone set an unused variable? Maybe I missed something? Do you know anything else?
It does make some sense, although this is not what I expected. Also, I'm getting different results...
If I understand correctly your test, all the fields of a structure share the same registerset. Which is silly, since AFAIU each member of the structure has a separate D3DXCONSTANT_DESC in the constant table, both on disk and in memory, there is no point the compiler should force the same registerset for all the struct members.
Under the constraint of forcing all the members in the same registerset, the "conversion rules" you mention make sense. In SM3 an if bool can be replaced by an if_comp with a float register and a rep/loop, which is controlled by an integer constant, can be emulated via loop unrolling (although I'm not sure how the compiler can possibly do that for the shader in your testcase). These are also pretty much the only use cases of bool and int constants and there are no int or bool "non-constant" registers so essentially no other type conversion is possible. You can check the plain text output from fxc to see how those constants are used in the shader code and how did the compiler manage to convert those constants from one type to another.
I tried to compile your HLSL shader myself (I had to disable optimization though, otherwise compilation fails) and, assuming the text output of fxc matches what actually ends up in the shader bytecode, in general I'm getting different struct members in different registersets. E.g. snbf gets allocated to c6-c9 and b8. FWIW, I used fxc from the June 2010 DirectX SDK, on Windows 7. I'm not sure why my results are different from yours. Or am I misunderstanding the test?
BTW, what needs to be fixed in Wine? I couldn't see anything obvious by reading the test.
Cheers, Matteo.
Cheers Rico