* [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
@ 2015-05-18 10:32 Kyrill Tkachov
2015-05-27 12:24 ` Kyrill Tkachov
2015-06-11 9:55 ` Ramana Radhakrishnan
0 siblings, 2 replies; 6+ messages in thread
From: Kyrill Tkachov @ 2015-05-18 10:32 UTC (permalink / raw)
To: GCC Patches; +Cc: Ramana Radhakrishnan, Richard Earnshaw
[-- Attachment #1: Type: text/plain, Size: 983 bytes --]
Hi all,
When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it will not end up generating a number of back-to-back cond_execs
that will later end up being back to back single-instruction IT blocks. Branching over them should be a better choice.
This patch implements that by setting max_insns_skipped to 1 when arm_restrict_it.
With this patch, I've seen GCC replace a number of sequences in places like SPEC2006 from:
it eq
moveq r1, r5
it ne
movne r1, r10
it eq
moveq r8, r4
to a branch over them.
Bootstrapped and tested on arm.
Ok for trunk?
Thanks,
Kyrill
2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* config/arm/arm.c (arm_option_params_internal): When optimising
for speed set max_insns_skipped when arm_restrict_it.
2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* gcc.target/arm/short-it-ifcvt-1.c: New test.
* gcc.target/arm/short-it-ifcvt-2.c: Likewise.
[-- Attachment #2: arm-restrict-it.patch --]
[-- Type: text/x-patch, Size: 2156 bytes --]
commit f23178a102c3f35d42d36e14ed69d6b03f5cd300
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Thu May 14 12:08:14 2015 +0100
[ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 3f1e48a..6b570af 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -2770,7 +2770,10 @@ arm_option_params_internal (struct gcc_options *opts)
max_insns_skipped = opts->x_arm_restrict_it ? 1 : 4;
}
else
- max_insns_skipped = current_tune->max_insns_skipped;
+ /* When -mrestrict-it is in use tone down the if-conversion. */
+ max_insns_skipped
+ = (TREE_TARGET_THUMB2 (opts) && opts->x_arm_restrict_it)
+ ? 1 : current_tune->max_insns_skipped;
}
/* Reset options between modes that the user has specified. */
diff --git a/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c
new file mode 100644
index 0000000..f3d29b7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c
@@ -0,0 +1,23 @@
+/* Test that ifcvt is not being too aggressive when -mrestrict-it. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mrestrict-it" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int
+f1(int x, int y, int z)
+{
+ if (x > 100)
+ {
+ x++;
+ z = -z;
+ }
+ else
+ {
+ x = -x;
+ y = -y;
+ z = 1;
+ }
+ return x + y + z;
+}
+
+/* { dg-final { scan-assembler "b(gt|le)" } } */
diff --git a/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c
new file mode 100644
index 0000000..9ac8153
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c
@@ -0,0 +1,21 @@
+/* Test that ifcvt is not being too aggressive when -mrestrict-it. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mrestrict-it" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int
+f1(int x, int y, int z)
+{
+ if (x > 100)
+ {
+ x++;
+ z = -z;
+ }
+ else
+ {
+ x = -x;
+ y = -y;
+ }
+ return x + y + z;
+}
+/* { dg-final { scan-assembler "b(gt|le)" } } */
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
2015-05-18 10:32 [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place Kyrill Tkachov
@ 2015-05-27 12:24 ` Kyrill Tkachov
2015-06-04 16:03 ` Kyrill Tkachov
2015-06-11 10:00 ` Ramana Radhakrishnan
2015-06-11 9:55 ` Ramana Radhakrishnan
1 sibling, 2 replies; 6+ messages in thread
From: Kyrill Tkachov @ 2015-05-27 12:24 UTC (permalink / raw)
To: GCC Patches; +Cc: Ramana Radhakrishnan, Richard Earnshaw
[-- Attachment #1: Type: text/plain, Size: 1180 bytes --]
Ping.
Here is the rebased (and retested) patch after Christian's series.
Thanks,
Kyrill
On 18/05/15 11:26, Kyrill Tkachov wrote:
> Hi all,
>
> When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it will not end up generating a number of back-to-back cond_execs
> that will later end up being back to back single-instruction IT blocks. Branching over them should be a better choice.
>
> This patch implements that by setting max_insns_skipped to 1 when arm_restrict_it.
>
> With this patch, I've seen GCC replace a number of sequences in places like SPEC2006 from:
> it eq
> moveq r1, r5
> it ne
> movne r1, r10
> it eq
> moveq r8, r4
>
> to a branch over them.
>
> Bootstrapped and tested on arm.
> Ok for trunk?
>
> Thanks,
> Kyrill
>
> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> * config/arm/arm.c (arm_option_params_internal): When optimising
> for speed set max_insns_skipped when arm_restrict_it.
>
> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> * gcc.target/arm/short-it-ifcvt-1.c: New test.
> * gcc.target/arm/short-it-ifcvt-2.c: Likewise.
[-- Attachment #2: arm-restrict-it.patch --]
[-- Type: text/x-patch, Size: 2169 bytes --]
commit 2e5bb6e122e96189af1774a4fa451ad7e9b44d3d
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Thu May 14 12:08:14 2015 +0100
[ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index a4eeba3..638d659 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -2788,7 +2788,10 @@ arm_option_params_internal (struct gcc_options *opts)
max_insns_skipped = opts->x_arm_restrict_it ? 1 : 4;
}
else
- max_insns_skipped = current_tune->max_insns_skipped;
+ /* When -mrestrict-it is in use tone down the if-conversion. */
+ max_insns_skipped
+ = (TARGET_THUMB2_P (opts->x_target_flags) && opts->x_arm_restrict_it)
+ ? 1 : current_tune->max_insns_skipped;
}
/* Reset options between modes that the user has specified. */
diff --git a/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c
new file mode 100644
index 0000000..f3d29b7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-1.c
@@ -0,0 +1,23 @@
+/* Test that ifcvt is not being too aggressive when -mrestrict-it. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mrestrict-it" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int
+f1(int x, int y, int z)
+{
+ if (x > 100)
+ {
+ x++;
+ z = -z;
+ }
+ else
+ {
+ x = -x;
+ y = -y;
+ z = 1;
+ }
+ return x + y + z;
+}
+
+/* { dg-final { scan-assembler "b(gt|le)" } } */
diff --git a/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c
new file mode 100644
index 0000000..9ac8153
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/short-it-ifcvt-2.c
@@ -0,0 +1,21 @@
+/* Test that ifcvt is not being too aggressive when -mrestrict-it. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mrestrict-it" } */
+/* { dg-require-effective-target arm_thumb2_ok } */
+
+int
+f1(int x, int y, int z)
+{
+ if (x > 100)
+ {
+ x++;
+ z = -z;
+ }
+ else
+ {
+ x = -x;
+ y = -y;
+ }
+ return x + y + z;
+}
+/* { dg-final { scan-assembler "b(gt|le)" } } */
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
2015-05-27 12:24 ` Kyrill Tkachov
@ 2015-06-04 16:03 ` Kyrill Tkachov
2015-06-11 9:49 ` Kyrill Tkachov
2015-06-11 10:00 ` Ramana Radhakrishnan
1 sibling, 1 reply; 6+ messages in thread
From: Kyrill Tkachov @ 2015-06-04 16:03 UTC (permalink / raw)
To: GCC Patches; +Cc: Ramana Radhakrishnan, Richard Earnshaw
Ping.
https://gcc.gnu.org/ml/gcc-patches/2015-05/msg02405.html
Thanks,
Kyrill
On 27/05/15 11:25, Kyrill Tkachov wrote:
> Ping.
>
> Here is the rebased (and retested) patch after Christian's series.
>
> Thanks,
> Kyrill
>
> On 18/05/15 11:26, Kyrill Tkachov wrote:
>> Hi all,
>>
>> When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it will not end up generating a number of back-to-back cond_execs
>> that will later end up being back to back single-instruction IT blocks. Branching over them should be a better choice.
>>
>> This patch implements that by setting max_insns_skipped to 1 when arm_restrict_it.
>>
>> With this patch, I've seen GCC replace a number of sequences in places like SPEC2006 from:
>> it eq
>> moveq r1, r5
>> it ne
>> movne r1, r10
>> it eq
>> moveq r8, r4
>>
>> to a branch over them.
>>
>> Bootstrapped and tested on arm.
>> Ok for trunk?
>>
>> Thanks,
>> Kyrill
>>
>> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>>
>> * config/arm/arm.c (arm_option_params_internal): When optimising
>> for speed set max_insns_skipped when arm_restrict_it.
>>
>> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>>
>> * gcc.target/arm/short-it-ifcvt-1.c: New test.
>> * gcc.target/arm/short-it-ifcvt-2.c: Likewise.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
2015-06-04 16:03 ` Kyrill Tkachov
@ 2015-06-11 9:49 ` Kyrill Tkachov
0 siblings, 0 replies; 6+ messages in thread
From: Kyrill Tkachov @ 2015-06-11 9:49 UTC (permalink / raw)
To: GCC Patches; +Cc: Ramana Radhakrishnan, Richard Earnshaw
Ping.
Thanks,
Kyrill
On 04/06/15 16:59, Kyrill Tkachov wrote:
> Ping.
> https://gcc.gnu.org/ml/gcc-patches/2015-05/msg02405.html
>
> Thanks,
> Kyrill
> On 27/05/15 11:25, Kyrill Tkachov wrote:
>> Ping.
>>
>> Here is the rebased (and retested) patch after Christian's series.
>>
>> Thanks,
>> Kyrill
>>
>> On 18/05/15 11:26, Kyrill Tkachov wrote:
>>> Hi all,
>>>
>>> When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it will not end up generating a number of back-to-back cond_execs
>>> that will later end up being back to back single-instruction IT blocks. Branching over them should be a better choice.
>>>
>>> This patch implements that by setting max_insns_skipped to 1 when arm_restrict_it.
>>>
>>> With this patch, I've seen GCC replace a number of sequences in places like SPEC2006 from:
>>> it eq
>>> moveq r1, r5
>>> it ne
>>> movne r1, r10
>>> it eq
>>> moveq r8, r4
>>>
>>> to a branch over them.
>>>
>>> Bootstrapped and tested on arm.
>>> Ok for trunk?
>>>
>>> Thanks,
>>> Kyrill
>>>
>>> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>>>
>>> * config/arm/arm.c (arm_option_params_internal): When optimising
>>> for speed set max_insns_skipped when arm_restrict_it.
>>>
>>> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>>>
>>> * gcc.target/arm/short-it-ifcvt-1.c: New test.
>>> * gcc.target/arm/short-it-ifcvt-2.c: Likewise.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
2015-05-18 10:32 [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place Kyrill Tkachov
2015-05-27 12:24 ` Kyrill Tkachov
@ 2015-06-11 9:55 ` Ramana Radhakrishnan
1 sibling, 0 replies; 6+ messages in thread
From: Ramana Radhakrishnan @ 2015-06-11 9:55 UTC (permalink / raw)
To: Kyrill Tkachov, GCC Patches; +Cc: Richard Earnshaw
On 18/05/15 11:26, Kyrill Tkachov wrote:
> Hi all,
>
> When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it will not end up generating a number of back-to-back cond_execs
> that will later end up being back to back single-instruction IT blocks. Branching over them should be a better choice.
>
> This patch implements that by setting max_insns_skipped to 1 when arm_restrict_it.
>
> With this patch, I've seen GCC replace a number of sequences in places like SPEC2006 from:
> it eq
> moveq r1, r5
> it ne
> movne r1, r10
> it eq
> moveq r8, r4
>
> to a branch over them.
>
> Bootstrapped and tested on arm.
> Ok for trunk?
Are you sure TREE_TARGET_THUMB2 is still valid in the code base after
Christian's latest round of ARM / Thumb patches ?
Ramana
>
> Thanks,
> Kyrill
>
> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> * config/arm/arm.c (arm_option_params_internal): When optimising
> for speed set max_insns_skipped when arm_restrict_it.
>
> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> * gcc.target/arm/short-it-ifcvt-1.c: New test.
> * gcc.target/arm/short-it-ifcvt-2.c: Likewise.
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place
2015-05-27 12:24 ` Kyrill Tkachov
2015-06-04 16:03 ` Kyrill Tkachov
@ 2015-06-11 10:00 ` Ramana Radhakrishnan
1 sibling, 0 replies; 6+ messages in thread
From: Ramana Radhakrishnan @ 2015-06-11 10:00 UTC (permalink / raw)
To: Kyrill Tkachov, GCC Patches; +Cc: Richard Earnshaw
On 27/05/15 11:25, Kyrill Tkachov wrote:
> Ping.
>
> Here is the rebased (and retested) patch after Christian's series.
>
> Thanks,
> Kyrill
>
> On 18/05/15 11:26, Kyrill Tkachov wrote:
>> Hi all,
>>
>> When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it will not end up generating a number of back-to-back cond_execs
>> that will later end up being back to back single-instruction IT blocks. Branching over them should be a better choice.
>>
>> This patch implements that by setting max_insns_skipped to 1 when arm_restrict_it.
>>
>> With this patch, I've seen GCC replace a number of sequences in places like SPEC2006 from:
>> it eq
>> moveq r1, r5
>> it ne
>> movne r1, r10
>> it eq
>> moveq r8, r4
>>
>> to a branch over them.
>>
>> Bootstrapped and tested on arm.
>> Ok for trunk?
Bah, opened the wrong message - yes this is OK.
Ramana
>>
>> Thanks,
>> Kyrill
>>
>> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>>
>> * config/arm/arm.c (arm_option_params_internal): When optimising
>> for speed set max_insns_skipped when arm_restrict_it.
>>
>> 2015-05-18 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>>
>> * gcc.target/arm/short-it-ifcvt-1.c: New test.
>> * gcc.target/arm/short-it-ifcvt-2.c: Likewise.
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-06-11 9:55 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-05-18 10:32 [PATCH][ARM] Restrict MAX_CONDITIONAL_EXECUTE when -mrestrict-it is in place Kyrill Tkachov
2015-05-27 12:24 ` Kyrill Tkachov
2015-06-04 16:03 ` Kyrill Tkachov
2015-06-11 9:49 ` Kyrill Tkachov
2015-06-11 10:00 ` Ramana Radhakrishnan
2015-06-11 9:55 ` Ramana Radhakrishnan
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).