On Mon, Sep 9, 2019 at 6:05 PM Wilco Dijkstra <wilco.dijks...@arm.com> wrote: > > Setting HONOR_REG_ALLOC_ORDER improves codesize with -Os, however it generates > slower and larger code with -O2 and higher. So only set it when optimizing > for > size. On Cortex-A57 this improves SPECINT2006 by 0.15% and SPECFP2006 by > 0.25% > while reducing codesize. > > Bootstrap OK, OK for commit? > > ChangeLog: > 2019-09-09 Wilco Dijkstra <wdijk...@arm.com> > > * config/arm/arm.h (HONOR_REG_ALLOC_ORDER): Set when optimizing for > size. > > -- > diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h > index > 8d023389eec469ad9c8a4e88edebdad5f3c23769..e3473e29fbbb964ff1136c226fbe30d35dbf7b39 > 100644 > --- a/gcc/config/arm/arm.h > +++ b/gcc/config/arm/arm.h > @@ -1065,9 +1065,8 @@ extern int arm_regs_in_sequence[]; > /* Use different register alloc ordering for Thumb. */ > #define ADJUST_REG_ALLOC_ORDER arm_order_regs_for_local_alloc () > > -/* Tell IRA to use the order we define rather than messing it up with its > - own cost calculations. */ > -#define HONOR_REG_ALLOC_ORDER 1 > +/* Tell IRA to use the order we define when optimizing for size. */ > +#define HONOR_REG_ALLOC_ORDER optimize_size
My only question would be whether it's more suitable to use optimize_function_for_size_p(cfun) instead as IIRC that gives us a chance with lto rather than the global optimize_size. Otherwise ok . regards Ramana > > /* Interrupt functions can only use registers that have already been > saved by the prologue, even if they would normally be
