[LLVMdev] Re: Newbie questions

Chris Lattner sabre at nondot.org
Wed Apr 26 21:16:46 PDT 2006

On Wed, 26 Apr 2006, Vikram Adve wrote:
> On Apr 26, 2006, at 11:02 PM, Chris Lattner wrote:
>>> By reordering two instructions that could throw exceptions.
>> One of us is confused.  The approach above never has instructions that 
>> throw exceptions.
> I think we're talking about different cases.  What you say is true about 
> Tom's first approach (explicit comparisons  before each potentially trapping 
> instruction).  I was talking about the second approach (taking a signal and 
> converting that to an exception).  That could be broken by reordering two 
> such instructions.

Ah, that explains it.  You're right, until LLVM has support for non-call 
exceptions, the second approach is not safe.  Thus he would have to use 
the first approach.



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