Displaying 4 results from an estimated 4 matches for "invariant_load".
2019 May 01
2
Assigning custom information to IR instruction and passing it to its correspondent in Selection DAG
...e an intrinsic to mark
the pointer itself instead of the instructions manipulating it, again it
depends on what you are modelling.
I've found that in the DAGBuilder metadata information connected with
> LoadInst instruction is utilized:
> bool isInvariant = I.getMetadata(LLVMContext::MD_invariant_load) !=
> nullptr;
>
> Is this metadata somehow protected against dropping - as you mentioned?
>
Nothing is protected as far as I know, the design is that it should always
be legal to drop a metadata.
I don’t know what the invariant_load information is used for at the place
you looked at,...
2016 Aug 25
3
invariant.load metadata semantics
...oy suggested the following:
Instead of "The existence of the !invariant.load metadata on the
instruction tells the optimizer and code generator that the address
operand to this load points to memory which can be assumed
unchanged." we say "It is undefined behavior to invariant_load from
a location that has been changed since it became dereferenceable".
In the current langref, I find "The existence" somewhat confusing,
since it seems to imply that adding dead code can change the
behavior of the program.
I don't want to specify the seman...
2016 Aug 25
4
invariant.load metadata semantics
...t;The existence of the !invariant.load metadata on the
> > > instruction tells the optimizer and code generator that the
> > > address
> > > operand to this load points to memory which can be assumed
> > > unchanged." we say "It is undefined behavior to invariant_load
> > > from
> > > a location that has been changed since it became
> > > dereferenceable".
> > > In the current langref, I find "The existence" somewhat
> > > confusing,
> > > since it seems to imply that adding dead code can chang...
2019 May 01
2
Assigning custom information to IR instruction and passing it to its correspondent in Selection DAG
On Tue, Apr 30, 2019 at 3:51 PM Przemyslaw Ossowski via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hi,
> as I wrote in mu previous post I wanted to somehow mark one IR instruction
> (in this particular case it would be 'load') during dedicated pass, which
> will set the marking based on neighboring instructions. Next I wanted to
> somehow to convey this marking