[PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Andrea Corallo]

[-- Attachment #1: Type: text/plain, Size: 349 bytes --]

Hi all,

I'd like to submit the following simple patch to clean some Low Loop
Overhead test failing on hard float configurations.

lob2.c and lob5.c are failing with: "'-mfloat-abi=hard': selected 
processor lacks an FPU".

lob3.c and lob5.c got "-mfloat-abi=soft and -mfloat-abi=hard may not
be used together".

Okay for trunk?

Thanks
  Andrea
  

[-- Attachment #2: 0001-arm-testsuite-fix-lob-tests-for-mfloat-abi-hard.patch --]
[-- Type: text/plain, Size: 3439 bytes --]

From ac47dfed0230d9fe596d27331b04ef194633927d Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.corallo@arm.com>
Date: Thu, 26 Nov 2020 12:33:18 +0100
Subject: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

2020-11-26  Andrea Corallo  <andrea.corallo@arm.com>

	* gcc.target/arm/lob2.c: Add '-mfpu=fp-armv8' flag.
	* gcc.target/arm/lob3.c: Skip with '-mfloat-abi=hard'.
	* gcc.target/arm/lob4.c: Likewise.
	* gcc.target/arm/lob5.c: Add '-mfpu=fp-armv8' flag.
---
 gcc/testsuite/gcc.target/arm/lob2.c | 2 +-
 gcc/testsuite/gcc.target/arm/lob3.c | 2 +-
 gcc/testsuite/gcc.target/arm/lob4.c | 2 +-
 gcc/testsuite/gcc.target/arm/lob5.c | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/gcc/testsuite/gcc.target/arm/lob2.c b/gcc/testsuite/gcc.target/arm/lob2.c
index fdeb2686f51..2a7e2fd3d89 100644
--- a/gcc/testsuite/gcc.target/arm/lob2.c
+++ b/gcc/testsuite/gcc.target/arm/lob2.c
@@ -2,7 +2,7 @@
    if a non-inlineable function call takes place inside the loop.  */
 /* { dg-do compile } */
 /* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
-/* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps" } */
+/* { dg-options "-march=armv8.1-m.main -mfpu=fp-armv8 -mthumb -O3 --save-temps" } */
 #include <stdlib.h>
 #include "lob.h"
 
diff --git a/gcc/testsuite/gcc.target/arm/lob3.c b/gcc/testsuite/gcc.target/arm/lob3.c
index 70314ea84b3..f5290063f28 100644
--- a/gcc/testsuite/gcc.target/arm/lob3.c
+++ b/gcc/testsuite/gcc.target/arm/lob3.c
@@ -1,7 +1,7 @@
 /* Check that GCC does not generate Armv8.1-M low over head loop instructions
    if causes VFP emulation library calls to happen inside the loop.  */
 /* { dg-do compile } */
-/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
+/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
 /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps -mfloat-abi=soft" } */
 /* { dg-require-effective-target arm_softfloat } */
 #include <stdlib.h>
diff --git a/gcc/testsuite/gcc.target/arm/lob4.c b/gcc/testsuite/gcc.target/arm/lob4.c
index 792f352d682..86c774e1b57 100644
--- a/gcc/testsuite/gcc.target/arm/lob4.c
+++ b/gcc/testsuite/gcc.target/arm/lob4.c
@@ -1,7 +1,7 @@
 /* Check that GCC does not generate Armv8.1-M low over head loop instructions
    if LR is modified within the loop.  */
 /* { dg-do compile } */
-/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
+/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
 /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps -mfloat-abi=soft" } */
 /* { dg-require-effective-target arm_softfloat } */
 #include <stdlib.h>
diff --git a/gcc/testsuite/gcc.target/arm/lob5.c b/gcc/testsuite/gcc.target/arm/lob5.c
index 1a6adf1e28e..ea8523d3c77 100644
--- a/gcc/testsuite/gcc.target/arm/lob5.c
+++ b/gcc/testsuite/gcc.target/arm/lob5.c
@@ -3,7 +3,7 @@
    therefore is not optimizable.  Outer loops are not optimized.  */
 /* { dg-do compile } */
 /* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
-/* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps" } */
+/* { dg-options "-march=armv8.1-m.main -mfpu=fp-armv8 -mthumb -O3 --save-temps" } */
 #include <stdlib.h>
 #include "lob.h"
 
-- 
2.20.1

Re: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Richard Earnshaw (lists)]

On 26/11/2020 13:53, Andrea Corallo via Gcc-patches wrote:
> Hi all,
> 
> I'd like to submit the following simple patch to clean some Low Loop
> Overhead test failing on hard float configurations.
> 
> lob2.c and lob5.c are failing with: "'-mfloat-abi=hard': selected 
> processor lacks an FPU".
> 
> lob3.c and lob5.c got "-mfloat-abi=soft and -mfloat-abi=hard may not
> be used together".
> 
> Okay for trunk?
> 
> Thanks
>   Andrea
>   
> 

I think it would be better to try to do this with suitable
require-effective-target rules (or something similar).  Forcing options
should generally be a last resort and in particular using -mfpu should
really be avoided as we're trying to move away from that.

diff --git a/gcc/testsuite/gcc.target/arm/lob4.c
b/gcc/testsuite/gcc.target/arm/lob4.c
...
-/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } {
"-marm" "-mcpu=*" } } */
+/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } {
"-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
 /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps
-mfloat-abi=soft" } */
 /* { dg-require-effective-target arm_softfloat } */

Why is the effective target arm_softfloat not solving this particular
conflict?

R.

Re: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Andrea Corallo]

"Richard Earnshaw (lists)" <Richard.Earnshaw@arm.com> writes:

> On 26/11/2020 13:53, Andrea Corallo via Gcc-patches wrote:
>> Hi all,
>> 
>> I'd like to submit the following simple patch to clean some Low Loop
>> Overhead test failing on hard float configurations.
>> 
>> lob2.c and lob5.c are failing with: "'-mfloat-abi=hard': selected 
>> processor lacks an FPU".
>> 
>> lob3.c and lob5.c got "-mfloat-abi=soft and -mfloat-abi=hard may not
>> be used together".
>> 
>> Okay for trunk?
>> 
>> Thanks
>>   Andrea
>>   
>> 
>
> I think it would be better to try to do this with suitable
> require-effective-target rules (or something similar).  Forcing options
> should generally be a last resort and in particular using -mfpu should
> really be avoided as we're trying to move away from that.
>
> diff --git a/gcc/testsuite/gcc.target/arm/lob4.c
> b/gcc/testsuite/gcc.target/arm/lob4.c
> ...
> -/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } {
> "-marm" "-mcpu=*" } } */
> +/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } {
> "-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
>  /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps
> -mfloat-abi=soft" } */
>  /* { dg-require-effective-target arm_softfloat } */
>
> Why is the effective target arm_softfloat not solving this particular
> conflict?

Good point,

I see is because we are defining __SOFTFP__ when compiling with
'-march=armv8.1-m.main+mve -mfloat-abi=hard'.

This sounds like a bug to me, correct?

If that's correct either we should consider also TARGET_HAVE_MVE and
TARGET_HAVE_MVE_FLOAT into arm_cpu_builtins when deciding for the
__SOFTFP__ definition or account them for our internal
TARGET_SOFT_FLOAT.  I guess the first is less invasive.

I'll come up with a patch unless I'm told that this is not a bug.

  Andrea

Re: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Andrea Corallo]

Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org> writes:

> "Richard Earnshaw (lists)" <Richard.Earnshaw@arm.com> writes:
>
>> On 26/11/2020 13:53, Andrea Corallo via Gcc-patches wrote:
>>> Hi all,
>>> 
>>> I'd like to submit the following simple patch to clean some Low Loop
>>> Overhead test failing on hard float configurations.
>>> 
>>> lob2.c and lob5.c are failing with: "'-mfloat-abi=hard': selected 
>>> processor lacks an FPU".
>>> 
>>> lob3.c and lob5.c got "-mfloat-abi=soft and -mfloat-abi=hard may not
>>> be used together".
>>> 
>>> Okay for trunk?
>>> 
>>> Thanks
>>>   Andrea
>>>   
>>> 
>>
>> I think it would be better to try to do this with suitable
>> require-effective-target rules (or something similar).  Forcing options
>> should generally be a last resort and in particular using -mfpu should
>> really be avoided as we're trying to move away from that.
>>
>> diff --git a/gcc/testsuite/gcc.target/arm/lob4.c
>> b/gcc/testsuite/gcc.target/arm/lob4.c
>> ...
>> -/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } {
>> "-marm" "-mcpu=*" } } */
>> +/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } {
>> "-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
>>  /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps
>> -mfloat-abi=soft" } */
>>  /* { dg-require-effective-target arm_softfloat } */
>>
>> Why is the effective target arm_softfloat not solving this particular
>> conflict?
>
> Good point,
>
> I see is because we are defining __SOFTFP__ when compiling with
> '-march=armv8.1-m.main+mve -mfloat-abi=hard'.
>
> This sounds like a bug to me, correct?

Hi Richard,

diving into it further I've been explained by a knowledgeable colleague
that '__SOFTFP__' indicates the use of emulated FP operations but says
nothing about the ABI, indeed this last is what we want to check here to
avoid the conflict.

OTOH our selector 'arm_softfloat' IIUC is claimed to select the ABI [1]

"ARM target uses the soft-float ABI with no floating-point instructions
used whatsoever (as selected with -mfloat-abi=soft). "

but is looking at '__SOFTFP__'.

What should be the right fix then?

Should we leave the skip "-mfloat-abi=hard" into the patch and update
the doc of the selector?

Thanks

  Andrea


[1] https://gcc.gnu.org/onlinedocs/gccint/Effective-Target-Keywords.html

[PATCH V2] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Andrea Corallo]

[-- Attachment #1: Type: text/plain, Size: 157 bytes --]

Hi all,

second version of this patch here fixing lob[2-5].c tests for hard float
abi targets implementing Kyrill's suggestions.

Okay for trunk?

  Andrea


[-- Attachment #2: 0001-arm-testsuite-fix-lob-tests-for-mfloat-abi-hard.patch --]
[-- Type: text/plain, Size: 3425 bytes --]

From f7f36b243c82a5dd49540cc48ceb8ce636872d5a Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.corallo@arm.com>
Date: Thu, 26 Nov 2020 12:33:18 +0100
Subject: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

2020-11-26  Andrea Corallo  <andrea.corallo@arm.com>

	* gcc.target/arm/lob2.c: Use '-march=armv8.1-m.main+fp'.
	* gcc.target/arm/lob3.c: Skip with '-mfloat-abi=hard'.
	* gcc.target/arm/lob4.c: Likewise.
	* gcc.target/arm/lob5.c: Use '-march=armv8.1-m.main+fp'.
---
 gcc/testsuite/gcc.target/arm/lob2.c | 2 +-
 gcc/testsuite/gcc.target/arm/lob3.c | 2 +-
 gcc/testsuite/gcc.target/arm/lob4.c | 2 +-
 gcc/testsuite/gcc.target/arm/lob5.c | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/gcc/testsuite/gcc.target/arm/lob2.c b/gcc/testsuite/gcc.target/arm/lob2.c
index fdeb2686f51..d174857b926 100644
--- a/gcc/testsuite/gcc.target/arm/lob2.c
+++ b/gcc/testsuite/gcc.target/arm/lob2.c
@@ -2,7 +2,7 @@
    if a non-inlineable function call takes place inside the loop.  */
 /* { dg-do compile } */
 /* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
-/* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps" } */
+/* { dg-options "-march=armv8.1-m.main+fp -mthumb -O3 --save-temps" } */
 #include <stdlib.h>
 #include "lob.h"
 
diff --git a/gcc/testsuite/gcc.target/arm/lob3.c b/gcc/testsuite/gcc.target/arm/lob3.c
index 70314ea84b3..f5290063f28 100644
--- a/gcc/testsuite/gcc.target/arm/lob3.c
+++ b/gcc/testsuite/gcc.target/arm/lob3.c
@@ -1,7 +1,7 @@
 /* Check that GCC does not generate Armv8.1-M low over head loop instructions
    if causes VFP emulation library calls to happen inside the loop.  */
 /* { dg-do compile } */
-/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
+/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
 /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps -mfloat-abi=soft" } */
 /* { dg-require-effective-target arm_softfloat } */
 #include <stdlib.h>
diff --git a/gcc/testsuite/gcc.target/arm/lob4.c b/gcc/testsuite/gcc.target/arm/lob4.c
index 792f352d682..86c774e1b57 100644
--- a/gcc/testsuite/gcc.target/arm/lob4.c
+++ b/gcc/testsuite/gcc.target/arm/lob4.c
@@ -1,7 +1,7 @@
 /* Check that GCC does not generate Armv8.1-M low over head loop instructions
    if LR is modified within the loop.  */
 /* { dg-do compile } */
-/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
+/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" "-mfloat-abi=hard" } } */
 /* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps -mfloat-abi=soft" } */
 /* { dg-require-effective-target arm_softfloat } */
 #include <stdlib.h>
diff --git a/gcc/testsuite/gcc.target/arm/lob5.c b/gcc/testsuite/gcc.target/arm/lob5.c
index 1a6adf1e28e..df5383b4a26 100644
--- a/gcc/testsuite/gcc.target/arm/lob5.c
+++ b/gcc/testsuite/gcc.target/arm/lob5.c
@@ -3,7 +3,7 @@
    therefore is not optimizable.  Outer loops are not optimized.  */
 /* { dg-do compile } */
 /* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
-/* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps" } */
+/* { dg-options "-march=armv8.1-m.main+fp -mthumb -O3 --save-temps" } */
 #include <stdlib.h>
 #include "lob.h"
 
-- 
2.20.1

Re: [PATCH V2] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Andrea Corallo]

Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org> writes:

> Hi all,
>
> second version of this patch here fixing lob[2-5].c tests for hard float
> abi targets implementing Kyrill's suggestions.
>
> Okay for trunk?
>
>   Andrea

Ping

RE: [PATCH V2] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Kyrylo Tkachov]

> -----Original Message-----
> From: Andrea Corallo <Andrea.Corallo@arm.com>
> Sent: 01 December 2020 10:13
> To: gcc-patches@gcc.gnu.org
> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; nd <nd@arm.com>;
> Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
> Subject: [PATCH V2] arm: [testsuite] fix lob tests for -mfloat-abi=hard
> 
> Hi all,
> 
> second version of this patch here fixing lob[2-5].c tests for hard float
> abi targets implementing Kyrill's suggestions.

Ok.
Thanks,
Kyrill

> 
> Okay for trunk?
> 
>   Andrea

Re: [PATCH V2] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Andrea Corallo]

Kyrylo Tkachov <Kyrylo.Tkachov@arm.com> writes:

>> -----Original Message-----
>> From: Andrea Corallo <Andrea.Corallo@arm.com>
>> Sent: 01 December 2020 10:13
>> To: gcc-patches@gcc.gnu.org
>> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; nd <nd@arm.com>;
>> Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
>> Subject: [PATCH V2] arm: [testsuite] fix lob tests for -mfloat-abi=hard
>> 
>> Hi all,
>> 
>> second version of this patch here fixing lob[2-5].c tests for hard float
>> abi targets implementing Kyrill's suggestions.
>
> Ok.
> Thanks,
> Kyrill

Into trunk as 695b8d281ad.

Thanks

  Andrea

RE: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard

[Kyrylo Tkachov]

Hi Andrea,

> -----Original Message-----
> From: Andrea Corallo <Andrea.Corallo@arm.com>
> Sent: 26 November 2020 13:54
> To: gcc-patches@gcc.gnu.org
> Cc: Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>; Richard Earnshaw
> <Richard.Earnshaw@arm.com>; nd <nd@arm.com>
> Subject: [PATCH] arm: [testsuite] fix lob tests for -mfloat-abi=hard
> 
> Hi all,
> 
> I'd like to submit the following simple patch to clean some Low Loop
> Overhead test failing on hard float configurations.
> 
> lob2.c and lob5.c are failing with: "'-mfloat-abi=hard': selected
> processor lacks an FPU".
> 
> lob3.c and lob5.c got "-mfloat-abi=soft and -mfloat-abi=hard may not
> be used together".
> 
> Okay for trunk?

diff --git a/gcc/testsuite/gcc.target/arm/lob2.c b/gcc/testsuite/gcc.target/arm/lob2.c
index fdeb2686f51..2a7e2fd3d89 100644
--- a/gcc/testsuite/gcc.target/arm/lob2.c
+++ b/gcc/testsuite/gcc.target/arm/lob2.c
@@ -2,7 +2,7 @@
    if a non-inlineable function call takes place inside the loop.  */
 /* { dg-do compile } */
 /* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
-/* { dg-options "-march=armv8.1-m.main -mthumb -O3 --save-temps" } */
+/* { dg-options "-march=armv8.1-m.main -mfpu=fp-armv8 -mthumb -O3 --save-temps" } */

We're trying to move away from using an explicit -mfpu (which is defaulted to "auto"). I think the march option should instead be -march=armv8.1-m.main+fp.

Thanks,
Kyrill

> 
> Thanks
>   Andrea
>