[LLVMdev] llvm-gcc promotes i32 mul to i64 inside __muldi3

[Sergey Yakoushkin]

> This shouldn't be necessary, IMO.  If you were going to implement it,
> then the correct thing to do would be to have generic selection dag
> lowering of large multiplies, which renders the library mostly
> useless.
In fact, I would prefer to avoid custom lowering for operations on large types.
i64 will be rare in my case (embedded) and their performance is not an issue.
I need basic i64 support only for functional correctness.

> Any soft int stuff that lowering hasn't already implemented.
Taking into account known issues with soft int staff...
Why expansion of large MULs/etc into smaller ones is not default
behavior of ExpandNode (LegalizeDAG)?
(seems meaningful if i32 operation is Legal or Custom)
Are there any plans to add that?

Regards,
Sergey Y.