[PATCH 1/2] wined3d: Correctly parse SM4 dcl_immediateConstantBuffer opcode.

[Józef Kucia]

This patch meant to be a minimal patch to prevent the infinitive loop.
It's mostly for bug 39153 which is "implement enough D3D11 to run Tomb
Raider 2013 without disabling d3d11 again" ;-) It allows the game to
crash properly instead of looping indefinitely. It crashes because of
some unsupported texture format with this patch. In order to make the
patch small I haven't added WINED3DSIH_ entry for this opcode yet.
Otherwise, I would have to reindent opcode tables also in shader.c,
arb_program_shader.c and glsl_shader.c. The subject should actually be
"wined3d: Correctly calculate length for SM4
dcl_immediateConstantBuffer opcode."

On Thu, Dec 3, 2015 at 4:48 PM, Henri Verbeet <hverbeet at gmail.com> wrote:
>>      opcode_token = *(*ptr)++;
>>      opcode = opcode_token & WINED3D_SM4_OPCODE_MASK;
>> -    len = ((opcode_token & WINED3D_SM4_INSTRUCTION_LENGTH_MASK) >> WINED3D_SM4_INSTRUCTION_LENGTH_SHIFT) - 1;
>> +
>> +    if (opcode == WINED3D_SM4_OP_DCL_IMMEDIATE_CONSTANT_BUFFER)
>> +        len = *(*ptr) - 1;
>> +    else
>> +        len = ((opcode_token & WINED3D_SM4_INSTRUCTION_LENGTH_MASK) >> WINED3D_SM4_INSTRUCTION_LENGTH_SHIFT) - 1;
>>
> I don't think this is the right place to handle this. You should be
> able to handle this the same way as the other DCL_ opcodes. It should
> probably also have an entry in the opcode_info table. (Compare e.g.
> 6d948e1a8cdd8a9a5ae2b6124468275cbf13f2b8.)
>

I think I still need some additional code to handle this case before
len is added to *ptr. WINED3D_SM4_INSTRUCTION_LENGTH is 0 for
DCL_IMMEDIATE_CONSTANT_BUFFER opcodes. In the result we are adding
4294967295 to the pointer. I could use other type than DWORD so it
would effectively decrement pointer pointer also on 64 bit but I doubt
we want that. I could also check if len is 0 before decrementing it
but it is not right for other opcodes than
DCL_IMMEDIATE_CONSTANT_BUFFER.