[llvm-commits] [llvm] r63642 - /llvm/trunk/lib/Target/X86/X86Subtarget.cpp

[Dale Johannesen]

On Feb 3, 2009, at 10:53 AMPST, Dan Gohman wrote:

> Author: djg
> Date: Tue Feb  3 12:53:21 2009
> New Revision: 63642
>
> URL: http://llvm.org/viewvc/llvm-project?rev=63642&view=rev
> Log:
> Tevert part of the x86 subtarget logic changes: when -march=x86-64
> is given, override the subtarget settings and enable 64-bit support.
> This restores the earlier behavior, and fixes regressions on
> Non-64-bit-capable x86-32 hosts.
>
> This isn't necessarily the best approach, but the most obvious
> alternative is to require -mcpu=x86-64 or -mattr=+64bit to be used
> with -march=x86-64 when the host doesn't have 64-bit support. This
> makes things little more consistent, but it's less convenient, and
> it has the practical drawback of requiring lots of test changes, so
> I opted for the above approach for now.

btw, is the interaction of -mcpu, -mattr and -march documented  
anywhere?  It should be.

> Modified:
>    llvm/trunk/lib/Target/X86/X86Subtarget.cpp
>
> Modified: llvm/trunk/lib/Target/X86/X86Subtarget.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.cpp?rev=63642&r1=63641&r2=63642&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/Target/X86/X86Subtarget.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86Subtarget.cpp Tue Feb  3 12:53:21  
> 2009
> @@ -327,15 +327,16 @@
>   } else {
>     // Otherwise, use CPUID to auto-detect feature set.
>     AutoDetectSubtargetFeatures();
> -    // If requesting codegen for X86-64, make sure that 64-bit  
> features
> -    // are enabled.
> -    if (Is64Bit)
> -      HasX86_64 = true;
>     // Make sure SSE2 is enabled; it is available on all X86-64 CPUs.
>     if (Is64Bit && X86SSELevel < SSE2)
>       X86SSELevel = SSE2;
>   }
>
> +  // If requesting codegen for X86-64, make sure that 64-bit features
> +  // are enabled.
> +  if (Is64Bit)
> +    HasX86_64 = true;
> +
>   DOUT << "Subtarget features: SSELevel " << X86SSELevel
>        << ", 3DNowLevel " << X863DNowLevel
>        << ", 64bit " << HasX86_64 << "\n";
>
>
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