[LLVMdev] LLVM and newlib progress

[Chris Lattner]

On Thu, 9 Nov 2006, Reid Spencer wrote:
>> Currently there are a few intrinsics that have
>> to do with libc, like llvm.memcpy and llvm.memmove. However, I
>> would personally prefer less pollution in the intrinsic name space,
>> so I would propose naming the intrinsics with a llvm.libc prefix,
>> e.g. llvm.libc.open and so forth. Any strong opinions on this?
>
> Yes, it should be completely unnecessary to use intrinsics at all unless
> there is a good optimization reason. The intrinsics we have are either
> lowered generically (e.g. llvm.bswap becomes a series of shifts) or
> lowered by the various targets into appropriate code for that target.
> However, there shouldn't be any reason to implement the system calls
> this way. Again, what issue are you trying to overcome that you think
> intrinsics is the solution?

As a specific example, compiling "printf" to llvm .bc form is very useful. 
However, printf ends up calling "write" at some point, which is a syscall. 
There isn't any really good reason to have an llvm intrinsic for write, 
just leave 'write' as an external function.

-Chris

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