* [PATCH] Adjust variable shift costs for IA MCU
@ 2015-07-09 18:05 H.J. Lu
2015-07-09 20:30 ` Uros Bizjak
2015-08-24 15:36 ` H.J. Lu
0 siblings, 2 replies; 4+ messages in thread
From: H.J. Lu @ 2015-07-09 18:05 UTC (permalink / raw)
To: gcc-patches; +Cc: Uros Bizjak
We reduce code size for IA MCU by adjusting variable shift costs for IA
MCU. OK for trunk?
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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] Adjust variable shift costs for IA MCU
2015-07-09 18:05 [PATCH] Adjust variable shift costs for IA MCU H.J. Lu
@ 2015-07-09 20:30 ` Uros Bizjak
2015-07-09 20:36 ` H.J. Lu
2015-08-24 15:36 ` H.J. Lu
1 sibling, 1 reply; 4+ messages in thread
From: Uros Bizjak @ 2015-07-09 20:30 UTC (permalink / raw)
To: H.J. Lu; +Cc: gcc-patches
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
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] Adjust variable shift costs for IA MCU
2015-07-09 20:30 ` Uros Bizjak
@ 2015-07-09 20:36 ` H.J. Lu
0 siblings, 0 replies; 4+ messages in thread
From: H.J. Lu @ 2015-07-09 20:36 UTC (permalink / raw)
To: Uros Bizjak; +Cc: gcc-patches
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.
--
H.J.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Adjust variable shift costs for IA MCU
2015-07-09 18:05 [PATCH] Adjust variable shift costs for IA MCU H.J. Lu
2015-07-09 20:30 ` Uros Bizjak
@ 2015-08-24 15:36 ` H.J. Lu
1 sibling, 0 replies; 4+ messages in thread
From: H.J. Lu @ 2015-08-24 15:36 UTC (permalink / raw)
To: gcc-patches, Uros Bizjak
On Thu, Jul 09, 2015 at 11:05:27AM -0700, H.J. Lu wrote:
> We reduce code size for IA MCU by adjusting variable shift costs for IA
> MCU. OK for trunk?
>
> Thanks.
>
>
> H.J.
> ---
> PR target/66821
> * config/i386/i386.c (iamcu_cost): Adjust variable shift costs.
I checked in this patch to add a testcase for PR target/66821.
H.J.
---
Index: ChangeLog
===================================================================
--- ChangeLog (revision 227132)
+++ ChangeLog (working copy)
@@ -1,5 +1,10 @@
2015-08-24 H.J. Lu <hongjiu.lu@intel.com>
+ PR target/66821
+ * gcc.target/i386/pr66821.c: New test.
+
+2015-08-24 H.J. Lu <hongjiu.lu@intel.com>
+
PR target/67329
* gcc.target/i386/pr67329.c: New test.
Index: gcc.target/i386/pr66821.c
===================================================================
--- gcc.target/i386/pr66821.c (revision 0)
+++ gcc.target/i386/pr66821.c (working copy)
@@ -0,0 +1,15 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -fdump-tree-optimized -mtune=iamcu" } */
+
+void bar (void);
+
+void
+foo (int x)
+{
+ if (x != 2 && x != 3 && x != 10 && x != 11 && x != 17 && x != 18 && x != 23)
+ bar ();
+}
+
+/* Check if the tests have been folded into a bit test. */
+/* { dg-final { scan-tree-dump "(8784908|0x0*860c0c)" "optimized" } } */
+/* { dg-final { scan-tree-dump "(<<|>>)" "optimized" } } */
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-07-09 18:05 [PATCH] Adjust variable shift costs for IA MCU H.J. Lu
2015-07-09 20:30 ` Uros Bizjak
2015-07-09 20:36 ` H.J. Lu
2015-08-24 15:36 ` H.J. Lu
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