Re: [wwwdocs] Mention ipa-ICF and auto-FDO

[Gerald Pfeifer <gerald at pfeifer dot com>]

Hi Honza,

thanks for putting this together.  Please find some notes below.
Can you please take these plus the other bits of feedback you got
and post an updated patch for a quick final check?

On Wednesday 2015-01-21 22:58, Jan Hubicka wrote:
> Index: changes.html
> ===================================================================
> +     <li>New identical code folding pass (controled via <code>-fipa-icf</code>).

"An Identical Code Folding (ICF) pass...has been added."

> +	 Compared to the identical code folding performed by Gold linker this

"by the Gold linker"

> +	 pass does not require function sections.  It also performs merging
> +	 pre-inline so inter-procedural optimizations are aware of the

pre-inlining or before inlining?

> +	 code re-use. On the other hand not all unifications performed
> +	 by linker are doable by GCC pass; the GCC pass must honnor

"by a linker"

"doable by GCC which must honor" (no double n in honor)

> +	 aliasing information. During link-time optimization of Firefox,
> +	 the pass unify about 29000 functions that is 10% overall</li>

"this pass unifies"

"that is..." -> "or 10% overall." (with full stop)

> +     <li>Devirtualization pass was significantly improved by adding

"The Devirtualization pass..."

> +      <li>New auto-FDO mode that use profiles collected by low overhead
> +	  profiling tools (perf) instead of more expensive program

"A new auto-FDO mode uses ..."

> +	  instrumentation (via <code>-fprofile-generate</code>). SPEC2006
> +	  benchmarks improve by 4.7% with auto-FDO and by 7.3% with
> +	  traditional feedback directed optimization.

On which architecture?

Gerald