[llvm-commits] [llvm] r134641 - in /llvm/trunk: lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h lib/Target/X86/X86.td lib/Target/X86/X86Subtarget.cpp lib/Target/X86/X86Subtarget.h lib/Target/X86/X86Ta

[Eli Friedman]

On Fri, Jul 8, 2011 at 2:57 PM, Evan Cheng <evan.cheng at apple.com> wrote:
>
> On Jul 8, 2011, at 2:55 PM, Eli Friedman wrote:
>
>> On Fri, Jul 8, 2011 at 2:54 PM, Evan Cheng <evan.cheng at apple.com> wrote:
>>>
>>> On Jul 8, 2011, at 2:35 PM, Eli Friedman wrote:
>>>
>>>> On Fri, Jul 8, 2011 at 2:15 PM, Evan Cheng <evan.cheng at apple.com> wrote:
>>>>> r134741 should handle the non-x86 hosts. For the other cases, we should either fix tests or add specific CPUs to X86.td.
>>>>
>>>> r134741 does't help at all.  Consider the case where we're compiling
>>>> for a triple like x86_64-apple-macosx10.7.0, no CPU is specified, and
>>>> we're on ARM.  We end up in 64-bit mode, but with cmov and SSE
>>>> disabled.  Stuff explodes.
>>>
>>> That's why this hack is in X86Subtarget.cpp:
>>>
>>>  // If requesting codegen for X86-64, make sure that 64-bit features
>>>  // are enabled.
>>>  // FIXME: Remove this feature since it's not actually being used.
>>>  if (In64BitMode) {
>>>    HasX86_64 = true;
>>>
>>>    // All 64-bit cpus have cmov support.
>>>    HasCMov = true;
>>>  }
>>
>> In64BitMode is unconditionally false.
>
> No ParseSubtargetFeatures can set it:
>  if ((Bits & X86::Mode64Bit) != 0) In64BitMode = true;

Oh, right... but the hack doesn't handle SSE.

-Eli