* [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default.
@ 2010-08-13 17:02 IainS
2010-08-13 17:22 ` Richard Henderson
2010-08-13 17:36 ` H.J. Lu
0 siblings, 2 replies; 6+ messages in thread
From: IainS @ 2010-08-13 17:02 UTC (permalink / raw)
To: GCC Patches; +Cc: mrs, Richard Henderson
Hi,
This brings the default arch on darwin to core2 - as per the OSX 4.2.1
system compiler.
(which makes our codegen much neater and takes a big chunk off the
size of cc1*).
---
In order to do that it was necessary to get -mtune=core2 to work ..
... this had a couple of residual cases where the use of movq is
incompatible with the darwin assembler.
The use of movd for r<->x and r<->Yi seems to be consistent with
the decisions made elsewhere in PRs (i.e. I am not disturbing the
status quo, merely making it consistent in a couple of missed places.)
I have bootstrapped this on x86_64 (Core 2 Duo), i686-darwin8 (Xeon)
and i686-darwin8 (Core Duo).
Note that the Darwin8 default for i686 from apple is nocona/gcc-4.0.1,
but the use of core2 here does not appear to create any problems
(the processor cannot execute m64 code anyway).
OK for trunk and 4.5?
Iain
Index: gcc/config/i386/mmx.md
===================================================================
--- gcc/config/i386/mmx.md (revision 163221)
+++ gcc/config/i386/mmx.md (working copy)
@@ -81,8 +81,8 @@
%vpxor\t%0, %d0
%vmovq\t{%1, %0|%0, %1}
%vmovq\t{%1, %0|%0, %1}
- %vmovq\t{%1, %0|%0, %1}
- %vmovq\t{%1, %0|%0, %1}"
+ %vmovd\t{%1, %0|%0, %1}
+ %vmovd\t{%1, %0|%0, %1}"
[(set_attr "type"
"imov
,imov
,mmx,mmxmov,mmxmov,ssecvt,ssecvt,sselog1,ssemov,ssemov,ssemov,ssemov")
(set_attr "unit" "*,*,*,*,*,mmx,mmx,*,*,*,*,*")
(set_attr "prefix_rep" "*,*,*,*,*,1,1,*,1,*,*,*")
Index: gcc/config/i386/sse.md
===================================================================
--- gcc/config/i386/sse.md (revision 163221)
+++ gcc/config/i386/sse.md (working copy)
@@ -7709,7 +7709,7 @@
"@
pinsrq\t{$0x1, %2, %0|%0, %2, 0x1}
movq\t{%1, %0|%0, %1}
- movq\t{%1, %0|%0, %1}
+ movd\t{%1, %0|%0, %1}
movq2dq\t{%1, %0|%0, %1}
punpcklqdq\t{%2, %0|%0, %2}
movlhps\t{%2, %0|%0, %2}
@@ -7728,7 +7728,7 @@
"TARGET_64BIT && TARGET_SSE"
"@
movq\t{%1, %0|%0, %1}
- movq\t{%1, %0|%0, %1}
+ movd\t{%1, %0|%0, %1}
movq2dq\t{%1, %0|%0, %1}
punpcklqdq\t{%2, %0|%0, %2}
movlhps\t{%2, %0|%0, %2}
Index: gcc/config.gcc
===================================================================
--- gcc/config.gcc (revision 163221)
+++ gcc/config.gcc (working copy)
@@ -1127,17 +1127,13 @@ hppa[12]*-*-hpux11*)
i[34567]86-*-darwin*)
need_64bit_hwint=yes
need_64bit_isa=yes
-
- # This is so that '.../configure && make' doesn't fail due to
- # config.guess deciding that the configuration is i386-*-darwin* and
- # then this file using that to set --with-cpu=i386 which has no -m64
- # support.
- with_cpu=${with_cpu:-generic}
+ # Baseline choice for a machine that allows m64 support.
+ with_cpu=${with_cpu:-core2}
tmake_file="${tmake_file} t-slibgcc-darwin i386/t-crtpc i386/t-crtfm"
lto_binary_reader=lto-macho
;;
x86_64-*-darwin*)
- with_cpu=${with_cpu:-generic}
+ with_cpu=${with_cpu:-core2}
tmake_file="${tmake_file} ${cpu_type}/t-darwin64 t-slibgcc-darwin
i386/t-crtpc i386/t-crtfm"
tm_file="${tm_file} ${cpu_type}/darwin64.h"
lto_binary_reader=lto-macho
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default.
2010-08-13 17:02 [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default IainS
@ 2010-08-13 17:22 ` Richard Henderson
2010-08-13 17:36 ` H.J. Lu
1 sibling, 0 replies; 6+ messages in thread
From: Richard Henderson @ 2010-08-13 17:22 UTC (permalink / raw)
To: IainS; +Cc: GCC Patches, mrs
On 08/13/2010 09:39 AM, IainS wrote:
> OK for trunk and 4.5?
Ok, with appropriate changelog.
r~
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default.
2010-08-13 17:02 [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default IainS
2010-08-13 17:22 ` Richard Henderson
@ 2010-08-13 17:36 ` H.J. Lu
2010-08-13 17:43 ` IainS
1 sibling, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2010-08-13 17:36 UTC (permalink / raw)
To: IainS; +Cc: GCC Patches, mrs, Richard Henderson
On Fri, Aug 13, 2010 at 9:39 AM, IainS <developer@sandoe-acoustics.co.uk> wrote:
> Hi,
>
> This brings the default arch on darwin to core2 - as per the OSX 4.2.1
> system compiler.
> (which makes our codegen much neater and takes a big chunk off the size of
> cc1*).
>
> ---
>
> In order to do that it was necessary to get -mtune=core2 to work ..
> ... this had a couple of residual cases where the use of movq is
> incompatible with the darwin assembler.
Do you know -mtune=core generates slower code than -mtune=generic?
> The use of movd for r<->x and r<->Yi seems to be consistent with the
> decisions made elsewhere in PRs (i.e. I am not disturbing the status quo,
> merely making it consistent in a couple of missed places.)
You should post a separate patch for this. Also there is no ChangeLog.
> I have bootstrapped this on x86_64 (Core 2 Duo), i686-darwin8 (Xeon) and
> i686-darwin8 (Core Duo).
> Note that the Darwin8 default for i686 from apple is nocona/gcc-4.0.1, but
> the use of core2 here does not appear to create any problems
> (the processor cannot execute m64 code anyway).
>
> OK for trunk and 4.5?
> Iain
--
H.J.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default.
2010-08-13 17:36 ` H.J. Lu
@ 2010-08-13 17:43 ` IainS
2010-08-13 19:38 ` Jack Howarth
0 siblings, 1 reply; 6+ messages in thread
From: IainS @ 2010-08-13 17:43 UTC (permalink / raw)
To: H.J. Lu; +Cc: GCC Patches, mrs, Richard Henderson
Hi HJ,
On 13 Aug 2010, at 18:22, H.J. Lu wrote:
> On Fri, Aug 13, 2010 at 9:39 AM, IainS <developer@sandoe-acoustics.co.uk
> > wrote:
>> In order to do that it was necessary to get -mtune=core2 to work ..
>> ... this had a couple of residual cases where the use of movq is
>> incompatible with the darwin assembler.
>
> Do you know -mtune=core generates slower code than -mtune=generic?
I have not benchmarked - unfortunately, we volunteers do not have
access to SPEC &c.
... but I observe that the code is circa 7% smaller with -mtune=core2
c.f. generic.
... and we replace all the _pc_thunk calls with a local call and pop -
which makes quite an impact on our asm.
If you can provide me with a realistic way to perform some suitable
benchmarks, I will happily do so.
.. otherwise, for the platform, I'm simply making our default the
same as the vendor's.
It does not, of course, prevent someone from bootstrapping with --with-
cpu=generic if they wish to.
thanks
Iain
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default.
2010-08-13 17:43 ` IainS
@ 2010-08-13 19:38 ` Jack Howarth
2010-08-13 19:40 ` IainS
0 siblings, 1 reply; 6+ messages in thread
From: Jack Howarth @ 2010-08-13 19:38 UTC (permalink / raw)
To: IainS; +Cc: H.J. Lu, GCC Patches, mrs, Richard Henderson
On Fri, Aug 13, 2010 at 06:36:12PM +0100, IainS wrote:
> Hi HJ,
>
> On 13 Aug 2010, at 18:22, H.J. Lu wrote:
>
>> On Fri, Aug 13, 2010 at 9:39 AM, IainS
>> <developer@sandoe-acoustics.co.uk> wrote:
>>> In order to do that it was necessary to get -mtune=core2 to work ..
>>> ... this had a couple of residual cases where the use of movq is
>>> incompatible with the darwin assembler.
>>
>> Do you know -mtune=core generates slower code than -mtune=generic?
>
> I have not benchmarked - unfortunately, we volunteers do not have access
> to SPEC &c.
Iain,
I can repeat the benchmarks this weekend but the last time I looked
at the performance of the Polyhedron 2005 benchmarks on x86_64-apple-darwin10,
I found -mtune=core2 was slower than -mtune=generic.
http://gcc.gnu.org/ml/gcc-patches/2010-02/msg01272.html
There were some earlier messages suggesting that improved cost models would
be under development this summer.
http://gcc.gnu.org/ml/gcc/2010-05/msg00279.html
http://gcc.gnu.org/ml/gcc/2010-05/msg00370.html
http://gcc.gnu.org/ml/gcc/2010-05/msg00427.html
If these do materialize and make it into gcc 4.6, it would make
sense to revisit this issue.
Jack
>
> ... but I observe that the code is circa 7% smaller with -mtune=core2
> c.f. generic.
> ... and we replace all the _pc_thunk calls with a local call and pop -
> which makes quite an impact on our asm.
>
> If you can provide me with a realistic way to perform some suitable
> benchmarks, I will happily do so.
> .. otherwise, for the platform, I'm simply making our default the same
> as the vendor's.
>
> It does not, of course, prevent someone from bootstrapping with --with-
> cpu=generic if they wish to.
>
> thanks
> Iain
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default.
2010-08-13 19:38 ` Jack Howarth
@ 2010-08-13 19:40 ` IainS
0 siblings, 0 replies; 6+ messages in thread
From: IainS @ 2010-08-13 19:40 UTC (permalink / raw)
To: Jack Howarth; +Cc: H.J. Lu, GCC Patches, mrs, Richard Henderson
On 13 Aug 2010, at 20:25, Jack Howarth wrote:
> On Fri, Aug 13, 2010 at 06:36:12PM +0100, IainS wrote:
>> Hi HJ,
>>
>> On 13 Aug 2010, at 18:22, H.J. Lu wrote:
>>
>>> On Fri, Aug 13, 2010 at 9:39 AM, IainS
>>> <developer@sandoe-acoustics.co.uk> wrote:
>>>> In order to do that it was necessary to get -mtune=core2 to work ..
>>>> ... this had a couple of residual cases where the use of movq is
>>>> incompatible with the darwin assembler.
>>>
>>> Do you know -mtune=core generates slower code than -mtune=generic?
>>
>> I have not benchmarked - unfortunately, we volunteers do not have
>> access
>> to SPEC &c.
> I can repeat the benchmarks this weekend but the last time I
> looked
> at the performance of the Polyhedron 2005 benchmarks on x86_64-apple-
> darwin10,
> I found -mtune=core2 was slower than -mtune=generic.
Do you have any reasonable body of c/c++ benchmarks?
I have the Polyhedron fortran ones.
Odd that the vendor would choose that default if it's genuinely less
performance...
I guess I could look and see if there are changed tuning params...
... anyway I'm not going to nail colors to the mast over this one -
it's easily changed.
... remember the old BYTE article "Lies, Damned Lies & Benchmarks" ?
cheers,
Iain
^ permalink raw reply [flat|nested] 6+ messages in thread
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2010-08-13 17:02 [Patch, Darwin, I386] enable mtune=core2 on darwin and make it the default IainS
2010-08-13 17:22 ` Richard Henderson
2010-08-13 17:36 ` H.J. Lu
2010-08-13 17:43 ` IainS
2010-08-13 19:38 ` Jack Howarth
2010-08-13 19:40 ` IainS
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