| Message ID | 20150709180527.GA29480@intel.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Jul 9, 2015 at 8:05 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: > We reduce code size for IA MCU by adjusting variable shift costs for IA > MCU. OK for trunk? IMO, tuning patches should fall into "obvious" category. I don't have any data to to do any meaningful review of a cost metric for a new target. So, instead of rubberstamping them again and again, these kind of patches are pre-approved for all non-algorithmic tuning changes for IAMCU target. Uros. > Thanks. > > > H.J. > --- > PR target/66821 > * config/i386/i386.c (iamcu_cost): Adjust variable shift costs. > --- > gcc/config/i386/i386.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c > index 85e59a8..e4e505c 100644 > --- a/gcc/config/i386/i386.c > +++ b/gcc/config/i386/i386.c > @@ -420,7 +420,7 @@ static const > struct processor_costs iamcu_cost = { > COSTS_N_INSNS (1), /* cost of an add instruction */ > COSTS_N_INSNS (1) + 1, /* cost of a lea instruction */ > - COSTS_N_INSNS (4), /* variable shift costs */ > + COSTS_N_INSNS (1), /* variable shift costs */ > COSTS_N_INSNS (1), /* constant shift costs */ > {COSTS_N_INSNS (11), /* cost of starting multiply for QI */ > COSTS_N_INSNS (11), /* HI */ > -- > 2.4.3 >
On Thu, Jul 9, 2015 at 1:30 PM, Uros Bizjak <ubizjak@gmail.com> wrote: > On Thu, Jul 9, 2015 at 8:05 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: >> We reduce code size for IA MCU by adjusting variable shift costs for IA >> MCU. OK for trunk? > > IMO, tuning patches should fall into "obvious" category. I don't have > any data to to do any meaningful review of a cost metric for a new > target. > > So, instead of rubberstamping them again and again, these kind of > patches are pre-approved for all non-algorithmic tuning changes for > IAMCU target. > I will keep it in mind. Thanks.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 85e59a8..e4e505c 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -420,7 +420,7 @@ static const struct processor_costs iamcu_cost = { COSTS_N_INSNS (1), /* cost of an add instruction */ COSTS_N_INSNS (1) + 1, /* cost of a lea instruction */ - COSTS_N_INSNS (4), /* variable shift costs */ + COSTS_N_INSNS (1), /* variable shift costs */ COSTS_N_INSNS (1), /* constant shift costs */ {COSTS_N_INSNS (11), /* cost of starting multiply for QI */ COSTS_N_INSNS (11), /* HI */