Hi Sumek,
Codec2 for embedded platforms is definitely in need of size
optimization by *removing
unused code for your chosen modes,* and speed optimization by *optimizing
the floating-point calculation.*
I think you might be wasting your time by pursuing structure and malloc()
optimizations, though. Consider what happens when you remove malloc and
place a variable on the stack. Instead of indexing through the heap
pointer, you are indexing through the stack pointer. You don't see the
stack pointer in the C code, but it's there. The instructions will probably
be very similar, especially on ARM, you can check this using the -S flag of
the compiler. When optimizing, *always* use -S to look at the instructions
generated by the compiler, this will show when an optimization is *really*
an optimization.
Similarly, removing a struct and using a local variable would still index
through the stack pointer.
The second problem with removing malloc() and structs is that it makes it
less likely that your work could be returned to David's codec2 sources.
Thanks
Bruce
On Mon, Jun 11, 2018 at 1:00 AM, sumek.wi via Freetel-codec2 <
freetel-codec2@lists.sourceforge.net> wrote:
> Hi,
>
>
> The reduced I said is program size. Also, I removed malloc and struct to
> make the program
>
> as simple as possible for embedded systems, and it also reduce the execute
> time by not
>
> indexing pointer.
>
>
> I used gcc on CodeLite, I don't know why it doesn't remove unreferenced
> much. Probably
>
> it is in debug mode.
>
>
> Sumek.
> ------------------------------
> *From:* Danilo Beuche <danilo.beu...@gmx.net>
> *Sent:* Monday, June 11, 2018 12:06:54 PM
> *To:* freetel-codec2@lists.sourceforge.net
> *Subject:* Re: [Freetel-codec2] noob in voice coding asking for help
> about Codec2 decoder.
>
>
> Hi,
>
> btw, using the gcc's -flto during compiling and linking does a great job
> of removing unused data and functions. Basically the gcc breaks up every
> file into individual linkable elements (each global variable and functions
> becomes an independent linkage element) and anything not referenced
> anywhere simply disappears from the final binary. Of course there is a lot
> more going on with -flto (LTO stands for link time optimization) but one of
> the side effects of using LTO is this removal of unreferenced elements from
> binary code.
>
> Other compilers have similar "tricks".
> Regards,
> Danilo
>
> On 11.06.2018 03:19, Bruce Perens wrote:
>
> Hi Sumek,
>
> I am curious about your memory saving strategy. Specifically, why using
> the stack vs. malloc() would result in a significant memory savings, and
> how removing structs would result in a significant memory savings.
>
> Perhaps you mean you are removing *unused *ones?
>
> Or is there something about the Windows compiler I don't understand?
>
> Thanks
>
> Bruce
>
> On Sun, Jun 10, 2018 at 1:40 PM, David Rowe <da...@rowetel.com> wrote:
>
> Hi Sumek,
>
> Oh I have one question, do you know if we can reduce the size of codebook
> especially lsp_cbjvm
>
>
> Many of those tables aren't used, so just link in the ones you need to
> support the Codec 2 modes you would like to use.
>
> Cheers,
>
> David
>
>
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> Bruce Perens K6BP - CEO, Legal Engineering
> Standards committee chair, license review committee member, co-founder,
> Open Source Initiative
> President, Open Research Institute; Board Member, Fashion Freedom
> Initiative.
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Standards committee chair, license review committee member, co-founder,
Open Source Initiative
President, Open Research Institute; Board Member, Fashion Freedom
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