[PATCH] rs6000: Improve .machine

[PATCH] rs6000: Improve .machine

[Segher Boessenkool]

Hi!

This adds more correct .machine for most older CPUs.  It should be
conservative in the sense that everything we handled before we handle at
least as well now.  This does not yet revamp the server CPU handling, it
is too risky at this point in time.

Tested on powerpc64-linux {-m32,-m64}.  Also manually tested with all
-mcpu=, and the output of that passed through the GNU assembler.

I plan to commit this later today.


Segher


2022-03-04  Segher Boessenkool  <segher@kernel.crashing.org>

	* config/rs6000/rs6000.c (rs6000_machine_from_flags): Restructure a bit.
	Handle most older CPUs.
---
 gcc/config/rs6000/rs6000.cc | 69 +++++++++++++++++++++++++++++++--------------
 1 file changed, 48 insertions(+), 21 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 78cc085d7855..f2b977bfe93c 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -5790,33 +5790,60 @@ const char *rs6000_machine;
 const char *
 rs6000_machine_from_flags (void)
 {
-  /* For some CPUs, the machine cannot be determined by ISA flags.  We have to
-     check them first.  */
-  switch (rs6000_cpu)
-    {
-    case PROCESSOR_PPC8540:
-    case PROCESSOR_PPC8548:
-      return "e500";
+  /* e300 and e500 */
+  if (rs6000_cpu == PROCESSOR_PPCE300C2 || rs6000_cpu == PROCESSOR_PPCE300C3)
+    return "e300";
+  if (rs6000_cpu == PROCESSOR_PPC8540 || rs6000_cpu == PROCESSOR_PPC8548)
+    return "e500";
+  if (rs6000_cpu == PROCESSOR_PPCE500MC)
+    return "e500mc";
+  if (rs6000_cpu == PROCESSOR_PPCE500MC64)
+    return "e500mc64";
+  if (rs6000_cpu == PROCESSOR_PPCE5500)
+    return "e5500";
+  if (rs6000_cpu == PROCESSOR_PPCE6500)
+    return "e6500";
 
-    case PROCESSOR_PPCE300C2:
-    case PROCESSOR_PPCE300C3:
-      return "e300";
+  /* 400 series */
+  if (rs6000_cpu == PROCESSOR_PPC403)
+    return "\"403\"";
+  if (rs6000_cpu == PROCESSOR_PPC405)
+    return "\"405\"";
+  if (rs6000_cpu == PROCESSOR_PPC440)
+    return "\"440\"";
+  if (rs6000_cpu == PROCESSOR_PPC476)
+    return "\"476\"";
 
-    case PROCESSOR_PPCE500MC:
-      return "e500mc";
+  /* A2 */
+  if (rs6000_cpu == PROCESSOR_PPCA2)
+    return "a2";
 
-    case PROCESSOR_PPCE500MC64:
-      return "e500mc64";
+  /* Cell BE */
+  if (rs6000_cpu == PROCESSOR_CELL)
+    return "cell";
 
-    case PROCESSOR_PPCE5500:
-      return "e5500";
+  /* Titan */
+  if (rs6000_cpu == PROCESSOR_TITAN)
+    return "titan";
 
-    case PROCESSOR_PPCE6500:
-      return "e6500";
+  /* 500 series and 800 series */
+  if (rs6000_cpu == PROCESSOR_MPCCORE)
+    return "\"821\"";
 
-    default:
-      break;
-    }
+  /* 600 series and 700 series, "classic" */
+  if (rs6000_cpu == PROCESSOR_PPC601 || rs6000_cpu == PROCESSOR_PPC603
+      || rs6000_cpu == PROCESSOR_PPC604 || rs6000_cpu == PROCESSOR_PPC604e
+      || rs6000_cpu == PROCESSOR_PPC750 || rs6000_cpu == PROCESSOR_POWERPC)
+    return "ppc";
+
+  /* Classic with AltiVec, "G4" */
+  if (rs6000_cpu == PROCESSOR_PPC7400 || rs6000_cpu == PROCESSOR_PPC7450)
+    return "\"7450\"";
+
+  /* The older 64-bit CPUs */
+  if (rs6000_cpu == PROCESSOR_PPC620 || rs6000_cpu == PROCESSOR_PPC630
+      || rs6000_cpu == PROCESSOR_RS64A || rs6000_cpu == PROCESSOR_POWERPC64)
+    return "ppc64";
 
   HOST_WIDE_INT flags = rs6000_isa_flags;
 
-- 
1.8.3.1

Re: [PATCH] rs6000: Improve .machine

[Joseph Myers]

This breaks the build of libgcc for powerpc-linux-gnu (32-bit, default 
CPU; configured --disable-multilib --enable-secureplt).

cc1: warning: The '-mfloat128' option may not be fully supported
/tmp/ccHCPzSh.s: Assembler messages:
/tmp/ccHCPzSh.s:163: Error: unrecognized opcode: `lfiwzx'
/scratch/jmyers/glibc-bot/src/gcc/libgcc/shared-object.mk:14: recipe for target '_kf_to_sd.o' failed
make[3]: *** [_kf_to_sd.o] Error 1

https://sourceware.org/pipermail/libc-testresults/2022q1/009421.html

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [PATCH] rs6000: Improve .machine

[Segher Boessenkool]

On Mon, Mar 07, 2022 at 08:53:42PM +0000, Joseph Myers wrote:
> This breaks the build of libgcc for powerpc-linux-gnu (32-bit, default 
> CPU; configured --disable-multilib --enable-secureplt).
> 
> cc1: warning: The '-mfloat128' option may not be fully supported
> /tmp/ccHCPzSh.s: Assembler messages:
> /tmp/ccHCPzSh.s:163: Error: unrecognized opcode: `lfiwzx'
> /scratch/jmyers/glibc-bot/src/gcc/libgcc/shared-object.mk:14: recipe for target '_kf_to_sd.o' failed
> make[3]: *** [_kf_to_sd.o] Error 1
> 
> https://sourceware.org/pipermail/libc-testresults/2022q1/009421.html

Thanks for the report!  This is now PR104829.


Segher

Re: [PATCH] rs6000: Improve .machine

[Sebastian Huber]

On 04/03/2022 17:51, Segher Boessenkool wrote:
> Hi!
> 
> This adds more correct .machine for most older CPUs.  It should be
> conservative in the sense that everything we handled before we handle at
> least as well now.  This does not yet revamp the server CPU handling, it
> is too risky at this point in time.
> 
> Tested on powerpc64-linux {-m32,-m64}.  Also manually tested with all
> -mcpu=, and the output of that passed through the GNU assembler.
> 
> I plan to commit this later today.

Could this be back ported to GCC 10 and 11? I would fix the following 
issue for -mcpu=405:

Error: unrecognized opcode: `dlmzb.'

-- 
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Re: [PATCH] rs6000: Improve .machine

[Segher Boessenkool]

Hi!

On Thu, Mar 10, 2022 at 09:25:21AM +0100, Sebastian Huber wrote:
> On 04/03/2022 17:51, Segher Boessenkool wrote:
> >This adds more correct .machine for most older CPUs.  It should be
> >conservative in the sense that everything we handled before we handle at
> >least as well now.  This does not yet revamp the server CPU handling, it
> >is too risky at this point in time.
> >
> >Tested on powerpc64-linux {-m32,-m64}.  Also manually tested with all
> >-mcpu=, and the output of that passed through the GNU assembler.
> >
> >I plan to commit this later today.
> 
> Could this be back ported to GCC 10 and 11? I would fix the following 
> issue for -mcpu=405:
> 
> Error: unrecognized opcode: `dlmzb.'

Good to hear!

Unfortunately there is PR104829 about this commit.  I don't see how the
commit can break anything (that wasn't already broken); it's not clear
how it happens at all, and neither me nor colleagues could reproduce it
so far.

So I won't yet backport it, but first wait what happens here.

Thanks for the report,


Segher

Re: [PATCH] rs6000: Improve .machine

[Sebastian Huber]

Hello Segher,

On 10/03/2022 11:11, Segher Boessenkool wrote:
> On Thu, Mar 10, 2022 at 09:25:21AM +0100, Sebastian Huber wrote:
>> On 04/03/2022 17:51, Segher Boessenkool wrote:
>>> This adds more correct .machine for most older CPUs.  It should be
>>> conservative in the sense that everything we handled before we handle at
>>> least as well now.  This does not yet revamp the server CPU handling, it
>>> is too risky at this point in time.
>>>
>>> Tested on powerpc64-linux {-m32,-m64}.  Also manually tested with all
>>> -mcpu=, and the output of that passed through the GNU assembler.
>>>
>>> I plan to commit this later today.
>> Could this be back ported to GCC 10 and 11? I would fix the following
>> issue for -mcpu=405:
>>
>> Error: unrecognized opcode: `dlmzb.'
> Good to hear!
> 
> Unfortunately there is PR104829 about this commit.  I don't see how the
> commit can break anything (that wasn't already broken); it's not clear
> how it happens at all, and neither me nor colleagues could reproduce it
> so far.
> 
> So I won't yet backport it, but first wait what happens here.

now that the PR104829 is fixed could I back port

Segher Boessenkool (2):
   rs6000: Improve .machine
   rs6000: Do not use rs6000_cpu for .machine ppc and ppc64 (PR104829)

to GCC 10 and 11?

-- 
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Dornierstr. 4
82178 Puchheim
Germany
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phone: +49-89-18 94 741 - 16
fax:   +49-89-18 94 741 - 08

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Re: [PATCH] rs6000: Improve .machine

[Segher Boessenkool]

Hi!

On Tue, Mar 15, 2022 at 03:29:23PM +0100, Sebastian Huber wrote:
> now that the PR104829 is fixed could I back port
> 
> Segher Boessenkool (2):
>   rs6000: Improve .machine
>   rs6000: Do not use rs6000_cpu for .machine ppc and ppc64 (PR104829)
> 
> to GCC 10 and 11?

I will do it, in a few days though.

Thanks for your enthusiasm :-),


Segher

Re: [PATCH] rs6000: Improve .machine

[Sebastian Huber]

Hello Segher,

On 15/03/2022 23:29, Segher Boessenkool wrote:
> On Tue, Mar 15, 2022 at 03:29:23PM +0100, Sebastian Huber wrote:
>> now that the PR104829 is fixed could I back port
>>
>> Segher Boessenkool (2):
>>    rs6000: Improve .machine
>>    rs6000: Do not use rs6000_cpu for .machine ppc and ppc64 (PR104829)
>>
>> to GCC 10 and 11?
> I will do it, in a few days though.
> 
> Thanks for your enthusiasm :-),

would now be a good time to back port the fixes or do you want to wait 
for the GCC 12 release? I would be nice if the fixes are included in the 
GCC 10.4 release.

-- 
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Dornierstr. 4
82178 Puchheim
Germany
email: sebastian.huber@embedded-brains.de
phone: +49-89-18 94 741 - 16
fax:   +49-89-18 94 741 - 08

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Re: [PATCH] rs6000: Improve .machine

[Sebastian Huber]

On 04/04/2022 11:31, Sebastian Huber wrote:
> Hello Segher,
> 
> On 15/03/2022 23:29, Segher Boessenkool wrote:
>> On Tue, Mar 15, 2022 at 03:29:23PM +0100, Sebastian Huber wrote:
>>> now that the PR104829 is fixed could I back port
>>>
>>> Segher Boessenkool (2):
>>>    rs6000: Improve .machine
>>>    rs6000: Do not use rs6000_cpu for .machine ppc and ppc64 (PR104829)
>>>
>>> to GCC 10 and 11?
>> I will do it, in a few days though.
>>
>> Thanks for your enthusiasm :-),
> 
> would now be a good time to back port the fixes or do you want to wait 
> for the GCC 12 release? I would be nice if the fixes are included in the 
> GCC 10.4 release.

The GCC 10.4 release candidate will be made on 21st June. May I pack 
port the two patches today?

-- 
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Herr Sebastian HUBER
Dornierstr. 4
82178 Puchheim
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email: sebastian.huber@embedded-brains.de
phone: +49-89-18 94 741 - 16
fax:   +49-89-18 94 741 - 08

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Re: [PATCH] rs6000: Improve .machine

[Segher Boessenkool]

On Mon, Jun 20, 2022 at 09:48:34AM +0200, Sebastian Huber wrote:
> On 04/04/2022 11:31, Sebastian Huber wrote:
> >Hello Segher,
> >
> >On 15/03/2022 23:29, Segher Boessenkool wrote:
> >>On Tue, Mar 15, 2022 at 03:29:23PM +0100, Sebastian Huber wrote:
> >>>now that the PR104829 is fixed could I back port
> >>>
> >>>Segher Boessenkool (2):
> >>>   rs6000: Improve .machine
> >>>   rs6000: Do not use rs6000_cpu for .machine ppc and ppc64 (PR104829)
> >>>
> >>>to GCC 10 and 11?
> >>I will do it, in a few days though.
> >>
> >>Thanks for your enthusiasm :-),
> >
> >would now be a good time to back port the fixes or do you want to wait 
> >for the GCC 12 release? I would be nice if the fixes are included in the 
> >GCC 10.4 release.
> 
> The GCC 10.4 release candidate will be made on 21st June. May I pack 
> port the two patches today?

Yes.  Thanks!


Segher