Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-28 Thread James Greenhalgh
On Wed, Jun 28, 2017 at 01:49:26PM +0100, Wilco Dijkstra wrote: > Ramana Radhakrishnan wrote: > >  > > I'm about to run home for the day but this came in from > > https://gcc.gnu.org/ml/gcc-patches/2013-09/msg02109.html and James > > said in that email that this was put in to ensure no segfaults

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-28 Thread Ramana Radhakrishnan
On 6/28/17 1:49 PM, Wilco Dijkstra wrote: Ramana Radhakrishnan wrote: I'm about to run home for the day but this came in from https://gcc.gnu.org/ml/gcc-patches/2013-09/msg02109.html and James said in that email that this was put in to ensure no segfaults on cortex-a15 / cortex-a7 tuning.

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-28 Thread Wilco Dijkstra
Ramana Radhakrishnan wrote: >  > I'm about to run home for the day but this came in from > https://gcc.gnu.org/ml/gcc-patches/2013-09/msg02109.html and James > said in that email that this was put in to ensure no segfaults on > cortex-a15 / cortex-a7 tuning. The code is historical - an older ve

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-27 Thread Ramana Radhakrishnan
On Wed, Jun 14, 2017 at 2:55 PM, James Greenhalgh wrote: > On Fri, May 05, 2017 at 05:02:46PM +0100, Wilco Dijkstra wrote: >> Richard Earnshaw (lists) wrote: >> >> > --- a/gcc/config/arm/aarch-common.c >> > +++ b/gcc/config/arm/aarch-common.c >> > @@ -254,12 +254,7 @@ arm_no_early_alu_shift_dep (r

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-27 Thread Wilco Dijkstra
ping   On Fri, May 05, 2017 at 05:02:46PM +0100, Wilco Dijkstra wrote: > Richard Earnshaw (lists) wrote: > > > --- a/gcc/config/arm/aarch-common.c > > +++ b/gcc/config/arm/aarch-common.c > > @@ -254,12 +254,7 @@ arm_no_early_alu_shift_dep (rtx producer, rtx consumer) > >  return 0; > > 

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-14 Thread James Greenhalgh
On Fri, May 05, 2017 at 05:02:46PM +0100, Wilco Dijkstra wrote: > Richard Earnshaw (lists) wrote: > > > --- a/gcc/config/arm/aarch-common.c > > +++ b/gcc/config/arm/aarch-common.c > > @@ -254,12 +254,7 @@ arm_no_early_alu_shift_dep (rtx producer, rtx consumer) > >  return 0; > >  > >    if ((

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-06-13 Thread Wilco Dijkstra
ping   Richard Earnshaw (lists) wrote: > --- a/gcc/config/arm/aarch-common.c > +++ b/gcc/config/arm/aarch-common.c > @@ -254,12 +254,7 @@ arm_no_early_alu_shift_dep (rtx producer, rtx consumer) >  return 0; >  >    if ((early_op = arm_find_shift_sub_rtx (op))) > -    { > -  if (REG_P (

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-05-05 Thread Wilco Dijkstra
Richard Earnshaw (lists) wrote: > --- a/gcc/config/arm/aarch-common.c > +++ b/gcc/config/arm/aarch-common.c > @@ -254,12 +254,7 @@ arm_no_early_alu_shift_dep (rtx producer, rtx consumer) >  return 0; >  >    if ((early_op = arm_find_shift_sub_rtx (op))) > -    { > -  if (REG_P (early_op))

Re: [PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-05-05 Thread Richard Earnshaw (lists)
On 27/04/17 18:38, Wilco Dijkstra wrote: > The aarch_forward_to_shift_is_not_shifted_reg bypass always returns true > on AArch64 shifted instructions. This causes the bypass to activate in > too many cases, resulting in slower execution on Cortex-A53 like reported > in PR79665. > > This patch use

[PATCH][AArch64] Improve Cortex-A53 shift bypass

2017-04-27 Thread Wilco Dijkstra
The aarch_forward_to_shift_is_not_shifted_reg bypass always returns true on AArch64 shifted instructions. This causes the bypass to activate in too many cases, resulting in slower execution on Cortex-A53 like reported in PR79665. This patch uses the arm_no_early_alu_shift_dep condition instead wh