[PATCH] D35577: Add -flookup-tables and -fno-lookup-tables flags

[Eric Christopher via Phabricator via cfe-commits]

echristo added a comment.

In https://reviews.llvm.org/D35577#817267, @sgundapa wrote:

> The discussion is scattered across these patches https://reviews.llvm.org/D35578 and https://reviews.llvm.org/D35579.
>  I will provide a brief summary here:
>
> The idea is to control the generation of data (lookup table) generated from a function, specifically when the user is not expecting it.
>  For hexagon, there is tightly coupled memory and the customers usually place "text" in it. 
>  For functions, which generate lookup tables, it is very very expensive to read the table from a far away non-TCM data section.
>  This option will disable the generation of lookup tables at the expense of code bloat. This is really driven by the customers of hexagon backend.


I don't think we're communicating effectively. Let me try another way:

"Is there any reason why a user of the hexagon backend will ever not want to set these options to a particular value"

in other words:

"Should this just be part of the tuning for the hexagon backend and not options at all"

Thanks.


https://reviews.llvm.org/D35577