[llvm-commits] [llvm] r67142 - in /llvm/trunk: lib/Target/X86/X86Instr64bit.td test/CodeGen/X86/call-imm.ll

[Chris Lattner]

On Mar 17, 2009, at 7:36 PM, Evan Cheng wrote:
> On Mar 17, 2009, at 7:17 PM, Chris Lattner wrote:
>> On Mar 17, 2009, at 7:03 PM, Evan Cheng wrote:
>>
>>> llvm only supports small code model fully. Medium and large code
>>> models are not fully baked. Perhaps this just need a
>>> Require<[SmallCode]>. It's true the call destination displacement  
>>> can
>>> be beyond 4G. But in small code model that's undefined behavior
>>> anyway, right?
>>
>> Why does "call <some random address>" imply that the address is in  
>> the
>> text segment?  I don't see what mcmodel has to do with this, nor do I
>
> No it doesn't. But how would that work?

Perhaps calling into device memory, firmware, or many other things.   
Even if it doesn't make "sense", we should not silently miscompile the  
program as we did before.

-Chris