* [RFC]: Fix Ada boostrap failure on S/390 with -mzarch
@ 2017-04-03 14:23 Andreas Krebbel
2017-04-03 16:18 ` Eric Botcazou
0 siblings, 1 reply; 5+ messages in thread
From: Andreas Krebbel @ 2017-04-03 14:23 UTC (permalink / raw)
To: ebotcazou; +Cc: gcc-patches
Hi Eric,
I ran into a similiar problem as PR80117 on S/390 starting with your
patch merging the system*.ads files for some biarch plattforms.
Starting with that change GCC does not bootstrap on S/390 when
configured with --with-mode=zarch.
On S/390 UNITS_PER_WORD is:
8 with -m64
4 with -m31
8 with -m31 -mzarch
This has been chosen to support use of 64 bit registers also in 32 bit
code. Code compiled with -m31 -mzarch is supposed to adhere to the 32
bit ABI. In order to make that work it was required to prevent
UNITS_PER_WORD from being used in ABI-relevant contexts. That's why
Ulrich added the TARGET_UNWIND_WORD_MODE in 2008 (for SPU).
More target hooks were needed for UNITS_PER_WORD uses in libgcc:
TARGET_LIBGCC_CMP_RETURN_MODE, and TARGET_LIBGCC_SHIFT_COUNT_MODE.
The use of the UNITS_PER_WORD in the system.ads files looks like
adding another ABI/API-relevant use to me.
Now I could either fix this by reverting that change for S/390
(similiar to what Andreas Schwab did to fix the BZ) or I could just
use the size of the long data type (as we do in the ABI-relevant parts
of the backend as well). Which one do you prefer?
Bye,
-Andreas-
diff --git a/gcc/ada/system-linux-s390.ads b/gcc/ada/system-linux-s390.ads
index 485a8de..144c46d 100644
--- a/gcc/ada/system-linux-s390.ads
+++ b/gcc/ada/system-linux-s390.ads
@@ -69,7 +69,7 @@ package System is
Null_Address : constant Address;
Storage_Unit : constant := 8;
- Word_Size : constant := Standard'Word_Size;
+ Word_Size : constant := Long_Integer'Size;
Memory_Size : constant := 2 ** Word_Size;
-- Address comparison
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC]: Fix Ada boostrap failure on S/390 with -mzarch
2017-04-03 14:23 [RFC]: Fix Ada boostrap failure on S/390 with -mzarch Andreas Krebbel
@ 2017-04-03 16:18 ` Eric Botcazou
2017-04-04 11:46 ` Andreas Krebbel
0 siblings, 1 reply; 5+ messages in thread
From: Eric Botcazou @ 2017-04-03 16:18 UTC (permalink / raw)
To: Andreas Krebbel; +Cc: gcc-patches
> On S/390 UNITS_PER_WORD is:
> 8 with -m64
> 4 with -m31
> 8 with -m31 -mzarch
>
> This has been chosen to support use of 64 bit registers also in 32 bit
> code. Code compiled with -m31 -mzarch is supposed to adhere to the 32
> bit ABI. In order to make that work it was required to prevent
> UNITS_PER_WORD from being used in ABI-relevant contexts. That's why
> Ulrich added the TARGET_UNWIND_WORD_MODE in 2008 (for SPU).
We do that for 32-bit SPARC on Solaris (-mv8plus) but UNITS_PER_WORD is 4.
> Now I could either fix this by reverting that change for S/390
> (similiar to what Andreas Schwab did to fix the BZ) or I could just
> use the size of the long data type (as we do in the ABI-relevant parts
> of the backend as well). Which one do you prefer?
Having System.Word_Size != Standard'Word_Size is a bit disturbing. Does it
work to change only Memory_Size to 2 ** Long_Integer'Size? This will also
correct the definition of Address below.
--
Eric Botcazou
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC]: Fix Ada boostrap failure on S/390 with -mzarch
2017-04-03 16:18 ` Eric Botcazou
@ 2017-04-04 11:46 ` Andreas Krebbel
2017-04-04 17:42 ` Eric Botcazou
2017-05-10 2:54 ` H.J. Lu
0 siblings, 2 replies; 5+ messages in thread
From: Andreas Krebbel @ 2017-04-04 11:46 UTC (permalink / raw)
To: Eric Botcazou; +Cc: gcc-patches
On 04/03/2017 06:18 PM, Eric Botcazou wrote:
>> On S/390 UNITS_PER_WORD is:
>> 8 with -m64
>> 4 with -m31
>> 8 with -m31 -mzarch
>>
>> This has been chosen to support use of 64 bit registers also in 32 bit
>> code. Code compiled with -m31 -mzarch is supposed to adhere to the 32
>> bit ABI. In order to make that work it was required to prevent
>> UNITS_PER_WORD from being used in ABI-relevant contexts. That's why
>> Ulrich added the TARGET_UNWIND_WORD_MODE in 2008 (for SPU).
>
> We do that for 32-bit SPARC on Solaris (-mv8plus) but UNITS_PER_WORD is 4.
>
>> Now I could either fix this by reverting that change for S/390
>> (similiar to what Andreas Schwab did to fix the BZ) or I could just
>> use the size of the long data type (as we do in the ABI-relevant parts
>> of the backend as well). Which one do you prefer?
>
> Having System.Word_Size != Standard'Word_Size is a bit disturbing. Does it
> work to change only Memory_Size to 2 ** Long_Integer'Size? This will also
> correct the definition of Address below.
This worked as well. I've committed the following patch:
gcc/ada/ChangeLog:
2017-04-04 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* system-linux-s390.ads: Use Long_Integer'Size to define
Memory_Size.
---
gcc/ada/system-linux-s390.ads | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/ada/system-linux-s390.ads b/gcc/ada/system-linux-s390.ads
index 485a8de..9bf8375 100644
--- a/gcc/ada/system-linux-s390.ads
+++ b/gcc/ada/system-linux-s390.ads
@@ -70,7 +70,7 @@ package System is
Storage_Unit : constant := 8;
Word_Size : constant := Standard'Word_Size;
- Memory_Size : constant := 2 ** Word_Size;
+ Memory_Size : constant := 2 ** Long_Integer'Size;
-- Address comparison
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC]: Fix Ada boostrap failure on S/390 with -mzarch
2017-04-04 11:46 ` Andreas Krebbel
@ 2017-04-04 17:42 ` Eric Botcazou
2017-05-10 2:54 ` H.J. Lu
1 sibling, 0 replies; 5+ messages in thread
From: Eric Botcazou @ 2017-04-04 17:42 UTC (permalink / raw)
To: Andreas Krebbel; +Cc: gcc-patches
> This worked as well. I've committed the following patch:
>
> gcc/ada/ChangeLog:
>
> 2017-04-04 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
>
> * system-linux-s390.ads: Use Long_Integer'Size to define
> Memory_Size.
Thanks!
--
Eric Botcazou
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC]: Fix Ada boostrap failure on S/390 with -mzarch
2017-04-04 11:46 ` Andreas Krebbel
2017-04-04 17:42 ` Eric Botcazou
@ 2017-05-10 2:54 ` H.J. Lu
1 sibling, 0 replies; 5+ messages in thread
From: H.J. Lu @ 2017-05-10 2:54 UTC (permalink / raw)
To: Andreas Krebbel; +Cc: Eric Botcazou, GCC Patches
On Tue, Apr 4, 2017 at 4:46 AM, Andreas Krebbel
<krebbel@linux.vnet.ibm.com> wrote:
> On 04/03/2017 06:18 PM, Eric Botcazou wrote:
>>> On S/390 UNITS_PER_WORD is:
>>> 8 with -m64
>>> 4 with -m31
>>> 8 with -m31 -mzarch
>>>
>>> This has been chosen to support use of 64 bit registers also in 32 bit
>>> code. Code compiled with -m31 -mzarch is supposed to adhere to the 32
>>> bit ABI. In order to make that work it was required to prevent
>>> UNITS_PER_WORD from being used in ABI-relevant contexts. That's why
>>> Ulrich added the TARGET_UNWIND_WORD_MODE in 2008 (for SPU).
>>
>> We do that for 32-bit SPARC on Solaris (-mv8plus) but UNITS_PER_WORD is 4.
>>
>>> Now I could either fix this by reverting that change for S/390
>>> (similiar to what Andreas Schwab did to fix the BZ) or I could just
>>> use the size of the long data type (as we do in the ABI-relevant parts
>>> of the backend as well). Which one do you prefer?
>>
>> Having System.Word_Size != Standard'Word_Size is a bit disturbing. Does it
>> work to change only Memory_Size to 2 ** Long_Integer'Size? This will also
>> correct the definition of Address below.
>
> This worked as well. I've committed the following patch:
>
> gcc/ada/ChangeLog:
>
> 2017-04-04 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
>
> * system-linux-s390.ads: Use Long_Integer'Size to define
> Memory_Size.
> ---
> gcc/ada/system-linux-s390.ads | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/ada/system-linux-s390.ads b/gcc/ada/system-linux-s390.ads
> index 485a8de..9bf8375 100644
> --- a/gcc/ada/system-linux-s390.ads
> +++ b/gcc/ada/system-linux-s390.ads
> @@ -70,7 +70,7 @@ package System is
>
> Storage_Unit : constant := 8;
> Word_Size : constant := Standard'Word_Size;
> - Memory_Size : constant := 2 ** Word_Size;
> + Memory_Size : constant := 2 ** Long_Integer'Size;
>
> -- Address comparison
>
X32 needs something similar:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80626
--
H.J.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-04-03 14:23 [RFC]: Fix Ada boostrap failure on S/390 with -mzarch Andreas Krebbel
2017-04-03 16:18 ` Eric Botcazou
2017-04-04 11:46 ` Andreas Krebbel
2017-04-04 17:42 ` Eric Botcazou
2017-05-10 2:54 ` H.J. Lu
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