| Message ID | 20240102083643.3055484-1-thomas.petazzoni@bootlin.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v3] Config.in: change default optimization level from -Os to -O2 | expand |
Thomas, All, On 2024-01-02 09:36 +0100, Thomas Petazzoni via buildroot spake thusly: > Historically, Buildroot has defaulted to -Os as the gcc optimization > flags. However, this default is probably not the most appropriate > anymore, and this commit therefore changes the default to -O2. > > Here are some arguments in favor of this change: > > - Most Buildroot users use Buildroot for platforms that have a > reasonable amount of storage, and the difference between -Os and -O2 > in terms of code size is no longer as significant compared to the > size of storage available on average embedded Linux devices > typically found these days. > > - -Os can have a pretty bad performance impact, compared to -O2. > > - -Os is much less widely tested than -O2. For example, with recent > versions of gcc, there are parts of Qt5 that segfault when compiled > with -Os and work perfectly fine with -O2. Yes, it's a compiler bug > that should be fixed, but in the mean time, having a default that's > more widely used/tested makes sense. > > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> > Acked-by: Yann E. MORIN <yann.morin.1998@free.fr> Applied to master, thanks. Regards, Yann E. MORIN. > --- > Config.in | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Config.in b/Config.in > index 554b4062eb..bd4bf872aa 100644 > --- a/Config.in > +++ b/Config.in > @@ -474,7 +474,7 @@ config BR2_STRIP_EXCLUDE_DIRS > > choice > prompt "gcc optimization level" > - default BR2_OPTIMIZE_S > + default BR2_OPTIMIZE_2 > help > Set the optimization level for gcc > > @@ -520,6 +520,7 @@ config BR2_OPTIMIZE_2 > -falign-loops -falign-labels -ftree-vrp -ftree-pre. Please > note the warning under -fgcse about invoking -O2 on programs > that use computed gotos. > + This is the default. > > config BR2_OPTIMIZE_3 > bool "optimization level 3" > @@ -548,7 +549,6 @@ config BR2_OPTIMIZE_S > -falign-loops -falign-labels -freorder-blocks > -freorder-blocks-and-partition -fprefetch-loop-arrays > -ftree-vect-loop-version > - This is the default. > > config BR2_OPTIMIZE_FAST > bool "optimize for fast (may break packages!)" > -- > 2.43.0 > > _______________________________________________ > buildroot mailing list > buildroot@buildroot.org > https://lists.buildroot.org/mailman/listinfo/buildroot
diff --git a/Config.in b/Config.in index 554b4062eb..bd4bf872aa 100644 --- a/Config.in +++ b/Config.in @@ -474,7 +474,7 @@ config BR2_STRIP_EXCLUDE_DIRS choice prompt "gcc optimization level" - default BR2_OPTIMIZE_S + default BR2_OPTIMIZE_2 help Set the optimization level for gcc @@ -520,6 +520,7 @@ config BR2_OPTIMIZE_2 -falign-loops -falign-labels -ftree-vrp -ftree-pre. Please note the warning under -fgcse about invoking -O2 on programs that use computed gotos. + This is the default. config BR2_OPTIMIZE_3 bool "optimization level 3" @@ -548,7 +549,6 @@ config BR2_OPTIMIZE_S -falign-loops -falign-labels -freorder-blocks -freorder-blocks-and-partition -fprefetch-loop-arrays -ftree-vect-loop-version - This is the default. config BR2_OPTIMIZE_FAST bool "optimize for fast (may break packages!)"