[LLVMdev] Intrinsics and it's documentation.

[Eli Friedman]

On Mon, Jul 7, 2008 at 6:41 PM, Mahadevan R <mdevan.foobar at gmail.com> wrote:
> On Tue, Jul 8, 2008 at 12:00 AM, Chris Lattner <sabre at nondot.org> wrote:
>> On Mon, 7 Jul 2008, Mahadevan R wrote:
>>> While going through the list of intrinsics in Intrinsics.td, I found
>>> that it does not match the list given in Language Reference [1]. Does
>>> this mean that they are not to be used / don't work? Or is it just
>>> that the documentation is outdated?
>>
>> Which one specifically?  It probably means they are missing documentation.
>
> Intrinsics only in Intrinsics.td:
>
> llvm.atomic.las
> llvm.atomic.lcs
> llvm.atomic.lss

Are you comparing trunk LangRef.html to trunk Intrinsics.td?  (The
trunk version of Intrinsics.td is at is at
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Intrinsics.td?revision=52706&view=markup.)

> llvm.flt.rounds

This is used to implement the FLT_ROUNDS macro in float.h; it
definitely should be documented.  (That said, at the moment, LLVM
doesn't correctly support messing with rounding modes at the moment;
it doesn't know that floating-point operations depend on the FP
control register.)

> llvm.longjmp
> llvm.setjmp
> llvm.siglongjmp
> llvm.sigsetjmp

These are used by the LowerSetJmp pass; however, llvm-gcc doesn't use
that pass, and the code itself hasn't been touched for years.  Anyone
know if LowerSetJmp still works/whether there are any known bugs/why
llvm-gcc isn't using this pass?

-Eli