[PATCH vkd3d 2/5] vkd3d-shader: Track bytecode buffer size in bytes.

[Zebediah Figura (she/her)]

On 6/30/21 7:44 AM, Matteo Bruni wrote:
> On Tue, Jun 29, 2021 at 8:00 PM Zebediah Figura <zfigura at codeweavers.com> wrote:
>>
>> And change the way we handle alignment.
>>
>> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
>> ---
>>   libs/vkd3d-shader/hlsl.h         |  4 +-
>>   libs/vkd3d-shader/hlsl_codegen.c | 92 +++++++++++++-------------------
>>   2 files changed, 39 insertions(+), 57 deletions(-)
>>
> 
>> diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
>> index 9afa590a..27bbd9b6 100644
>> --- a/libs/vkd3d-shader/hlsl_codegen.c
>> +++ b/libs/vkd3d-shader/hlsl_codegen.c
> 
>> @@ -1631,20 +1612,21 @@ static void write_sm1_uniforms(struct hlsl_ctx *ctx, struct bytecode_buffer *buf
>>       {
>>           if (!var->semantic.name && var->reg.allocated)
>>           {
>> -            set_dword(buffer, vars_start + (uniform_count * 5), (buffer->count - ctab_start) * sizeof(*buffer->data));
>> +            size_t var_offset = vars_start + (uniform_count * 5 * sizeof(uint32_t));
>> +
>> +            set_dword(buffer, var_offset, buffer->size - ctab_start);
>>               put_string(buffer, var->name);
>>
>>               write_sm1_type(buffer, var->data_type, ctab_start);
>> -            set_dword(buffer, vars_start + (uniform_count * 5) + 3,
>> -                    (var->data_type->bytecode_offset - ctab_start) * sizeof(*buffer->data));
>> +            set_dword(buffer, var_offset + 3 * sizeof(uint32_t), var->data_type->bytecode_offset - ctab_start);
>>               ++uniform_count;
>>           }
>>       }
>>
>>       offset = put_string(buffer, vkd3d_shader_get_version(NULL, NULL));
>> -    set_dword(buffer, creator_offset, (offset - ctab_start) * sizeof(*buffer->data));
>> +    set_dword(buffer, creator_offset, offset - ctab_start);
>>
>> -    set_dword(buffer, size_offset, D3DSIO_COMMENT | ((buffer->count - (ctab_start - 1)) << 16));
>> +    set_dword(buffer, size_offset, D3DSIO_COMMENT | (((buffer->size - (ctab_start - 1)) / sizeof(uint32_t)) << 16));
> 
> I think this is broken, or at least changed from previous output, for
> two different reasons: buffer->size is now not aligned (since
> alignment happens on the following put_bytes()) and we want to
> subtract ctab_start - 1 * sizeof(DWORD) (or, equivalently,
> strlen("CTAB")) from the current offset.
> 
> I suggest to replace all the raw uses of buffer->size with a helper
> call e.g. size_t get_current_offset_aligned(buffer, alignment) to make
> sure we're not falling into this trap.
> 

Yeah, this is broken. I think the helper makes sense; naming it is hard, 
but...