Still valid with 3.6.1:

$ llc --version
LLVM (http://llvm.org/):
  LLVM version 3.6.1
  Optimized build.
  Built Jul  6 2015 (07:08:46).
  Default target: aarch64-redhat-linux-gnu
  Host CPU: (unknown)

  Registered Targets:
    aarch64    - AArch64 (little endian)
    aarch64_be - AArch64 (big endian)
    amdgcn     - AMD GCN GPUs
    arm        - ARM
    arm64      - ARM64 (little endian)
    armeb      - ARM (big endian)
    cpp        - C++ backend
    nvptx      - NVIDIA PTX 32-bit
    nvptx64    - NVIDIA PTX 64-bit
    ppc32      - PowerPC 32
    ppc64      - PowerPC 64
    ppc64le    - PowerPC 64 LE
    r600       - AMD GPUs HD2XXX-HD6XXX
    systemz    - SystemZ
    thumb      - Thumb
    thumbeb    - Thumb (big endian)
    x86        - 32-bit X86: Pentium-Pro and above
    x86-64     - 64-bit X86: EM64T and AMD64

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I tested this on armhfp with LLVM 3.9.1 and it was working.

(In reply to Tom Stellard from comment #4)
> I tested this on armhfp with LLVM 3.9.1 and it was working.

really? 

$ llc --version
LLVM (http://llvm.org/):
  LLVM version 3.9.1
  Optimized build.
  Default target: armv7l-unknown-linux-gnueabihf
  Host CPU: (unknown)

  Registered Targets:
    aarch64    - AArch64 (little endian)
    aarch64_be - AArch64 (big endian)
    amdgcn     - AMD GCN GPUs
    arm        - ARM
    arm64      - ARM64 (little endian)
    armeb      - ARM (big endian)
    bpf        - BPF (host endian)
    bpfeb      - BPF (big endian)
    bpfel      - BPF (little endian)
    mips       - Mips
    mips64     - Mips64 [experimental]
    mips64el   - Mips64el [experimental]
    mipsel     - Mipsel
    nvptx      - NVIDIA PTX 32-bit
    nvptx64    - NVIDIA PTX 64-bit
    ppc32      - PowerPC 32
    ppc64      - PowerPC 64
    ppc64le    - PowerPC 64 LE
    r600       - AMD GPUs HD2XXX-HD6XXX
    systemz    - SystemZ
    thumb      - Thumb
    thumbeb    - Thumb (big endian)
    x86        - 32-bit X86: Pentium-Pro and above
    x86-64     - 64-bit X86: EM64T and AMD64
$

Which processor are you testing on?

(In reply to Tom Stellard from comment #6)
> Which processor are you testing on?

ARMv7 Cortex-A7

Also on a Cortex-A57 (aarch64):

$ llc --version
LLVM (http://llvm.org/):
  LLVM version 3.9.1
  Optimized build.
  Default target: aarch64-unknown-linux-gnu
  Host CPU: (unknown)

  Registered Targets:
    aarch64    - AArch64 (little endian)
    aarch64_be - AArch64 (big endian)
    amdgcn     - AMD GCN GPUs
    arm        - ARM
    arm64      - ARM64 (little endian)
    armeb      - ARM (big endian)
    bpf        - BPF (host endian)
    bpfeb      - BPF (big endian)
    bpfel      - BPF (little endian)
    mips       - Mips
    mips64     - Mips64 [experimental]
    mips64el   - Mips64el [experimental]
    mipsel     - Mipsel
    nvptx      - NVIDIA PTX 32-bit
    nvptx64    - NVIDIA PTX 64-bit
    ppc32      - PowerPC 32
    ppc64      - PowerPC 64
    ppc64le    - PowerPC 64 LE
    r600       - AMD GPUs HD2XXX-HD6XXX
    systemz    - SystemZ
    thumb      - Thumb
    thumbeb    - Thumb (big endian)
    x86        - 32-bit X86: Pentium-Pro and above
    x86-64     - 64-bit X86: EM64T and AMD64

So it seems cortex-a9 reports correctly: 

llc --version
LLVM (http://llvm.org/):
  LLVM version 3.9.1
  Optimized build.
  Default target: armv7l-unknown-linux-gnueabihf
  Host CPU: cortex-a9

  Registered Targets:
    aarch64    - AArch64 (little endian)
    aarch64_be - AArch64 (big endian)
    amdgcn     - AMD GCN GPUs
    arm        - ARM
    arm64      - ARM64 (little endian)
    armeb      - ARM (big endian)
    bpf        - BPF (host endian)
    bpfeb      - BPF (big endian)
    bpfel      - BPF (little endian)
    mips       - Mips
    mips64     - Mips64 [experimental]
    mips64el   - Mips64el [experimental]
    mipsel     - Mipsel
    nvptx      - NVIDIA PTX 32-bit
    nvptx64    - NVIDIA PTX 64-bit
    ppc32      - PowerPC 32
    ppc64      - PowerPC 64
    ppc64le    - PowerPC 64 LE
    r600       - AMD GPUs HD2XXX-HD6XXX
    systemz    - SystemZ
    thumb      - Thumb
    thumbeb    - Thumb (big endian)
    x86        - 32-bit X86: Pentium-Pro and above
    x86-64     - 64-bit X86: EM64T and AMD64

So I'd say better but not fixed....

(In reply to Peter Robinson from comment #9)
> So it seems cortex-a9 reports correctly: 
> 
> llc --version
> LLVM (http://llvm.org/):
>   LLVM version 3.9.1
>   Optimized build.
>   Default target: armv7l-unknown-linux-gnueabihf
>   Host CPU: cortex-a9

Oh and even though it reports the host cpu correctly the triple still is not.

What should the triple be?

Also, can you post /proc/cpuinfo for the systems where it doesn't work.

(In reply to Tom Stellard from comment #11)
> What should the triple be?

I would have thought it would be the red hat standard triplet as used in fedora/rhel but it seems that x86 reports unknown too so possibly not (or it's a separate bug).

LLVM (http://llvm.org/):
  LLVM version 3.9.1
  Optimized build.
  Default target: x86_64-unknown-linux-gnu
  Host CPU: broadwell

Mustang x-gene (Cortex-A57):

processor       : 0
BogoMIPS        : 100.00
Features        : fp asimd evtstrm
CPU implementer : 0x50
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0x000
CPU revision    : 0

AllWinner H3 (Cortex A7):

processor       : 0
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 48.00
Features        : half thumb fastmult vfp edsp thumbee neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm 
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

I can cross check others later if you want a full list across all the platforms I have available but please confirm it's useful

AllWinner A20 (Cortex A7):

processor       : 0
model name      : ARMv7 Processor rev 4 (v7l)
BogoMIPS        : 7.57
Features        : half thumb fastmult vfp edsp thumbee neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm 
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 4

bcm2836 (Cortex A7):
processor       : 0
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp thumbee neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

bcm2837 (Cortex A53) ARMv8 aarch64 CPU running with ARMv7 32 bit OS:
processor       : 0
model name      : ARMv7 Processor rev 4 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32 
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xd03
CPU revision    : 4

Clang uses "unknown" in the triple too (of course) and so does Rust.  I sort of figured this was the culture of LLVM. :)

If LLVM changes, I only hope this will not affect Rust yet, because a lot of the other tooling is not ready to deal with anything but "unknown".  There are a few open issues about this, to just ignore the vendor part.
https://github.com/rust-lang/rfcs/issues/1763
https://github.com/rust-lang/rust/issues/33147

(I'm referring only to the unknown vendor in the triple, not the host cpu.)

The auto-detection for ARM is very simple, it just parses the output of /proc/cpuinfo and uses the CPU part number to look up the corresponding cpu string in a table.  The table is missing some entries which is why it displays (unknown) for some of the ARM CPUs.

However, the 'Host CPU' value returned by llc only matters if you pass the  option -mcpu=native to llc or other tools.  If you don't specify any -mcpu it just compiles for a 'generic' CPU for your target.

It's not a good idea for applications to use llc to determine CPU type.  They should use some other more reliable method or just pass -mcpu=native to llc/clang.

Well it's caused us issues in the past and hence this bug... some of the detail is documented here, some likely forgotten in the intervening time since this bug was opened in 2014 so you'll have to forgive me for that, but most of the detail should be documented above

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

The issue with POCl was fixed upstream by d7f89ad2696a253296a5116bd89fe3031de1fb1c

Applications should either be using -march=native or doing their own CPU detection if they really care about optimizing for a specific CPU.

Were there any applications besides pocl, which were hitting this bug?

> Were there any applications besides pocl, which were hitting this bug?

Not that I can remember offhand but it was a long time ago we dealt with a lot of this, I think we're good to close this one out, anything new is likely a different issues