On 28/07/15 11:25, Kyrill Tkachov wrote: > Hi all, > > Currently we assign the wrong rtx cost to instructions of the form > add x0, x0, x1, sxtw > > that is, an arith operation plus a single extend (no shifting). > We correctly catch the cases where the extend is inside a shift, but > not the simple case. > > This patch fixes that oversight by catching the simple case in > aarch64_rtx_arith_op_extract_p and thus making sure that it gets > assigned the alu.extend_arith extra cost. > > Bootstrapped and tested on aarch64. > > Ok for trunk?
OK. R. > Thanks, > Kyrill > > > 2015-07-28 Kyrylo Tkachov <kyrylo.tkac...@arm.com> > > * config/aarch64/aarch64.c (aarch64_rtx_arith_op_extract_p): > Handle simple SIGN_EXTEND or ZERO_EXTEND. > (aarch64_rtx_costs): Properly strip extend or extract before > passing down to rtx costs again. > > > aarch64-arith-extend-costs.patch > > > commit 6ad208ea10b0893b356dab9d0c6f59821441229c > Author: Kyrylo Tkachov <kyrylo.tkac...@arm.com> > Date: Fri Jul 24 15:02:10 2015 +0100 > > [AArch64] Properly handle simple arith+extend ops in rtx costs > > diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c > index 617c079..eb70c30 100644 > --- a/gcc/config/aarch64/aarch64.c > +++ b/gcc/config/aarch64/aarch64.c > @@ -5622,6 +5622,11 @@ aarch64_rtx_arith_op_extract_p (rtx x, machine_mode > mode) > return true; > } > } > + /* The simple case <ARITH>, XD, XN, XM, [us]xt. > + No shift. */ > + else if (GET_CODE (x) == SIGN_EXTEND > + || GET_CODE (x) == ZERO_EXTEND) > + return REG_P (XEXP (x, 0)); > > return false; > } > @@ -6133,7 +6138,8 @@ cost_minus: > if (speed) > *cost += extra_cost->alu.extend_arith; > > - *cost += rtx_cost (XEXP (XEXP (op1, 0), 0), VOIDmode, > + op1 = aarch64_strip_extend (op1); > + *cost += rtx_cost (op1, VOIDmode, > (enum rtx_code) GET_CODE (op1), 0, speed); > return true; > } > @@ -6211,7 +6217,8 @@ cost_plus: > if (speed) > *cost += extra_cost->alu.extend_arith; > > - *cost += rtx_cost (XEXP (XEXP (op0, 0), 0), VOIDmode, > + op0 = aarch64_strip_extend (op0); > + *cost += rtx_cost (op0, VOIDmode, > (enum rtx_code) GET_CODE (op0), 0, speed); > return true; > } >
