Hi all, I have this problem:
I’m using LLVM’s C++ API, mostly
IRBuilder<> to generate code. Some of the generated code is just storing constant data to a location provided as a function argument. Something like
ir_builder.CreateStore(get_default_data(), ptrValue) where
get_default_data() may return a
ptrValue is a function argument. Looking at the generated assembly, it seems inefficient, it generates a separate instruction for storing each byte relative to the pointer. Each instruction takes several bytes, and I am trying to optimize for code size.
The Q: What should I do to make the generated code more size-efficient (think
Current ideas, which may not include the best answer:
- Store the data as-is in the IR, and use the
MemCpyInstinstead of the store when
get_default_data()returns something big?
- Add a custom – or any available built-in – pass to the output to transform the store instns to memcpy when appropriate?
Thanks for any help,
This message and any attachments are intended for the use of the addressee or addressees only. The unauthorised disclosure, use, dissemination or copying (either in whole or in part) of its content is not permitted. If you received this message in error, please notify the sender and delete it from your system. Emails can be altered and their integrity cannot be guaranteed by the sender. Please consider the environment before printing this email.