From owner-freebsd-toolchain@FreeBSD.ORG  Tue Nov  8 22:06:11 2011
Return-Path: <owner-freebsd-toolchain@FreeBSD.ORG>
Delivered-To: freebsd-toolchain@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id CBECE106564A;
	Tue,  8 Nov 2011 22:06:11 +0000 (UTC) (envelope-from dim@FreeBSD.org)
Received: from tensor.andric.com (cl-327.ede-01.nl.sixxs.net
	[IPv6:2001:7b8:2ff:146::2])
	by mx1.freebsd.org (Postfix) with ESMTP id 8DD6F8FC15;
	Tue,  8 Nov 2011 22:06:11 +0000 (UTC)
Received: from [IPv6:2001:7b8:3a7:0:e5f2:b2e3:287d:70bb] (unknown
	[IPv6:2001:7b8:3a7:0:e5f2:b2e3:287d:70bb])
	(using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits))
	(No client certificate requested)
	by tensor.andric.com (Postfix) with ESMTPSA id CFAFF5C59;
	Tue,  8 Nov 2011 23:06:10 +0100 (CET)
Message-ID: <4EB9A7D1.9030800@FreeBSD.org>
Date: Tue, 08 Nov 2011 23:06:09 +0100
From: Dimitry Andric <dim@FreeBSD.org>
Organization: The FreeBSD Project
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64;
	rv:8.0) Gecko/20111031 Thunderbird/8.0
MIME-Version: 1.0
To: Alexander Best <arundel@freebsd.org>
References: <20111108002556.GA91218@freebsd.org> <4EB8E07B.5070908@FreeBSD.org>
	<20111108153856.GA90966@freebsd.org>
	<20111108210420.GA37161@freebsd.org>
In-Reply-To: <20111108210420.GA37161@freebsd.org>
X-Enigmail-Version: 1.3.3
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: freebsd-toolchain@freebsd.org
Subject: Re: CPUTYPE=native handling
X-BeenThere: freebsd-toolchain@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Maintenance of FreeBSD's integrated toolchain
	<freebsd-toolchain.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain>, 
	<mailto:freebsd-toolchain-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-toolchain>
List-Post: <mailto:freebsd-toolchain@freebsd.org>
List-Help: <mailto:freebsd-toolchain-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain>, 
	<mailto:freebsd-toolchain-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 08 Nov 2011 22:06:11 -0000

On 2011-11-08 22:04, Alexander Best wrote:
...
> for me -march=native reports:
> 
> otaku% gcc -march=native -E -v - </dev/null
> Using built-in specs.
> Target: amd64-undermydesk-freebsd
> Configured with: FreeBSD/amd64 system compiler
> Thread model: posix
> gcc version 4.2.2 20070831 prerelease [FreeBSD]
>  /usr/libexec/cc1 -E -quiet -v -D_LONGLONG - -march=nocona -mtune=generic
> #include "..." search starts here:
> #include <...> search starts here:
>  /usr/include/gcc/4.2
>  /usr/include
> End of search list.
> # 1 "<stdin>"
> # 1 "<built-in>"
> # 1 "<command-line>"
> # 1 "<stdin>"
> 
> where instead of nocona, core2 would have been the better choice:
> 
> [1.000000] CPU: Intel(R) Pentium(R) Dual  CPU  E2160  @ 1.80GHz (1800.00-MHz K8-class CPU)
> [1.000000]   Origin = "GenuineIntel"  Id = 0x6fd  Family = 6  Model = f  Stepping = 13
> [1.000000]   Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
> [1.000000]   Features2=0xe39d<SSE3,DTES64,MON,DS_CPL,EST,TM2,SSSE3,CX16,xTPR,PDCM>
> [1.000000]   AMD Features=0x20100800<SYSCALL,NX,LM>
> [1.000000]   AMD Features2=0x1<LAHF>
> [1.000000]   TSC: P-state invariant, performance statistics

That's weird, the logic in gcc goes:

  cpuid (1, eax, ebx, ecx, edx);
...
  has_ssse3 = !!(ecx & bit_SSSE3);
...
          if (arch)
            {
              if (has_ssse3)
                cpu = "core2";
              else if (has_sse3)
                {
                  if (has_longmode)
                    cpu = "nocona";
                  else
                    cpu = "prescott";
                }
              else if (has_sse2)
                cpu = "pentium4";
              else if (has_cmov)
                cpu = "pentiumpro";
              else if (has_mmx)
                cpu = "pentium-mmx";
              else if (has_cmpxchg8b)
                cpu = "pentium";
              else
                cpu = "i386";
            }
          else
            cpu = "generic";
          goto done;

E.g. it seems to conclude your cpu *doesn't* have SSSE3, but does have
long mode, and thus jumps to nocona.

You might be able to debug this, by putting some printfs in this
function. :)