[PATCH 1/3] ipa-reorder-for-locality - Adjust bootstrap-lto-locality to reduce compile time

[Jan Hubicka]

> Hi,
> 
> As discussed at Cauldron, I’m sending a 3 patch series that addresses the review comments about the compile-time improvement and introduces C++ template heuristics which requires the data structure support added in the compile-time patch [2/3].
> 
> [Patch 1/3]
> This patch turns off -fipa-reorder-for-locality for -fprofile-generate because
> it's not required and contributes to the bloated time taken by bootstrap.  It
> also reduces the partition size by half; the increased number of partitions
> speeds up LTRANS phase.
> 
> Bootstrapped and tested on aarch64-none-linux-gnu. OK for mainline?
This really feels like a workaround especially with the --param value.
Can't we just adjust the default to get reasonable build times? How much
difference you see with the value change in benchmarks?

Honza
> 
> Signed-off-by: Prachi Godbole <pgodbole@nvidia.com>
> 
> config/ChangeLog:
> 
> 	* bootstrap-lto-locality.mk (STAGE2_CFLAGS): Add param
> 	lto-max-locality-partition.
> 	(STAGE3_CFLAGS): Ditto.
> 	(STAGEprofile_CFLAGS): Remove -fipa-reorder-for-locality.
> 	(STAGEtrain_CFLAGS): Ditto.
>