J721EXSOMXEVM: ti-arm-clang - struct alignment

Anton Annenkov

Part Number: J721EXSOMXEVM

Hi,

In ti-cgt-arm, there was a table for register and memory storage for various data types:
https://www.ti.com/lit/ug/spnu151v/spnu151v.pdf?ts=1678357337747&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252Fdownload%252FARM-CGT
Table 6-2:

"struct Members are stored as their individual types require. Members are stored as their individual types require; aligned according to the member with the most restrictive alignment requirement."

We have tried to find a similar statement for ti-arm-clang, but cannot find it in the documentation.
Could you clarify how this is handled in ti-arm-clang?
We are using version 1.3.0.LTS (14 May 2021)

BR,
Anton Annenkov

over 2 years ago

0 George Mock over 2 years ago

TI__Guru**** 251290 points

Please see the Object Representation part of the tiarmclang online manual.

Thanks and regards,

-George

0 Anton Annenkov over 2 years ago in reply to George Mock

Intellectual 435 points

Thank you.

We found "-mno-unaligned-access" which seems to work, but we would like to have 4-byte alignment of structs/unions/arrays.
Using #pragma pack(4) seems like the only option that we can find from:

https://software-dl.ti.com/codegen/docs/tiarmclang/compiler_tools_user_guide/migration_guide/migrating_c_and_cpp_source/pragmas_and_attributes.html?highlight=pragma%20pack

/Anton

0 George Mock over 2 years ago in reply to Anton Annenkov

TI__Guru**** 251290 points

Just for the moment, please ignore how you might implement the solution. What overall problem do you want to solve?

Thanks and regards,

-George

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J721EXSOMXEVM: ti-arm-clang - struct alignment