[llvm-commits] [llvm-gcc-4.2] r82640 - /llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp

[Dan Gohman]

On Sep 23, 2009, at 3:32 PM, Dale Johannesen wrote:

> On Sep 23, 2009, at 3:26 PMPDT, Dan Gohman wrote:
>
>> Using an intrinsic to convey "this function need not set errno" seem
>> like a very heavy-weight solution. Wouldn't it be better to make use
>> of the "readonly" or "readnone" function attributes? A "sqrt" call
>> with "readonly" can be known to not set errno.
>
> As far as errno goes, I agree that would be better, but we'd also  
> like to recognize it as sqrt for the purpose of generating sqrt  
> instructions on appropriate hardware.   Without an intrinsic we'd  
> need to do name lookup, I guess, which seems inappropriate for non-C- 
> based languages.

It's all the latest fashion apparently. LLVM now recognizes "malloc"
magically, for example.

Dan