sparse-llvm casts needed on function call arguments and returns

sparse-llvm casts needed on function call arguments and returns

[Dibyendu Majumdar]

It appears that both function call arguments and returns from
functions need to be cast to the expected type in sparse-llvm. This
may be because the linearizer is eliminating casts - I am not sure.
From LLVM perspective two pointers to different base types are not the
same - similarly various integer types and floating types are not
interchangeable.

By adding casts to store operations (both op_store and op_phisrc) as
well as in function call arguments the number of errors I am getting
when compiling 'minilua' has reduced significantly. However still 192
errors remain (but hopefully many will go with the next fix!).

Of course even with all errors being fixed it doesn't mean that the
generated code is right. Only when I run the program on Lua test suite
it will become apparent whether the generated code is correct or not.

Regards
Dibyendu

Re: sparse-llvm casts needed on function call arguments and returns

[Luc Van Oostenryck]

On Tue, Mar 14, 2017 at 10:48:53AM +0000, Dibyendu Majumdar wrote:
> It appears that both function call arguments and returns from
> functions need to be cast to the expected type in sparse-llvm. This
> may be because the linearizer is eliminating casts - I am not sure.

It's one of the cause, yes.
But again, in sparse the type are in the instructions, not in the values.

> From LLVM perspective two pointers to different base types are not the
> same - similarly various integer types and floating types are not
> interchangeable.
> 
> By adding casts to store operations (both op_store and op_phisrc) as
> well as in function call arguments the number of errors I am getting
> when compiling 'minilua' has reduced significantly. However still 192
> errors remain (but hopefully many will go with the next fix!).
> 
> Of course even with all errors being fixed it doesn't mean that the
> generated code is right. Only when I run the program on Lua test suite
> it will become apparent whether the generated code is correct or not.

Things should be greatly improved in the llvm-fixes-v3 serie
I submitted yesterday.

-- Luc