yaxunl added inline comments.
================ Comment at: lib/Headers/opencl-c.h:16020 +// The macro CLK_NULL_RESERVE_ID refers to an invalid reservation ID. +#define CLK_NULL_RESERVE_ID (__builtin_astype((void *)0, reserve_id_t)) bool __ovld is_valid_reserve_id(reserve_id_t reserve_id); ---------------- yaxunl wrote: > bader wrote: > > yaxunl wrote: > > > Anastasia wrote: > > > > echuraev wrote: > > > > > yaxunl wrote: > > > > > > Anastasia wrote: > > > > > > > yaxunl wrote: > > > > > > > > Anastasia wrote: > > > > > > > > > Looks good from my side. > > > > > > > > > > > > > > > > > > @yaxunl , since you originally committed this. Could you > > > > > > > > > please verify that changing from `SIZE_MAX` to `0` would be > > > > > > > > > fine. > > > > > > > > > > > > > > > > > > Btw, we have a similar definition for `CLK_NULL_EVENT`. > > > > > > > > `__PIPE_RESERVE_ID_VALID_BIT` is implementation detail and not > > > > > > > > part of the spec. I would suggest to remove it from this header > > > > > > > > file. > > > > > > > > > > > > > > > > The spec only requires CLK_NULL_RESERVE_ID to be defined but > > > > > > > > does not define its value. Naturally a valid id starts from 0 > > > > > > > > and increases. I don't see significant advantage to change > > > > > > > > CLK_NULL_RESERVE_ID from __SIZE_MAX to 0. > > > > > > > > > > > > > > > > Is there any reason that this change is needed? > > > > > > > I don't see issues to commit things outside of spec as soon as > > > > > > > they prefixed properly with "__". But I agree it would be nice > > > > > > > to see if it's any useful and what the motivation is for having > > > > > > > different implementation. > > > > > > For `__PIPE_RESERVE_ID_VALID_BIT`, it assumes that the > > > > > > implementation uses one specific bit of a reserve id to indicate > > > > > > that the reserve id is valid. Not all implementations assume that. > > > > > > Actually I am curious why that is needed too. > > > > > About `CLK_NULL_RESERVE_ID`: we check that reserve id is valid if > > > > > significant bit equal to one. `CLK_NULL_RESERVE_ID refers to an > > > > > invalid reservation, so if `CLK_NULL_RESERVE_ID equal to 0, we can be > > > > > sure that significant bit doesn't equal to 1 and it is invalid > > > > > reserve id. Also it is more obviously if CLK_**NULL**_RESERVE_ID is > > > > > equal to 0. > > > > > > > > > > What about `__PIPE_RESERVE_ID_VALID_BIT`: As I understand previous > > > > > implementation also assumes that one specific bit was of a reverse id > > > > > was used to indicate that the reserve id is valid. So, we just > > > > > increased reserve id size by one bit on 32-bit platforms and by 33 > > > > > bits on 64-bit platforms. > > > > It is more logical to me that `CLK_NULL_RESERVE_ID` is 0, but spec > > > > doesn't define it of course. > > > In our implementation, valid reserve id starts at 0 and increasing > > > linearly until `__SIZE_MAX-1`. This change will break our implementation. > > > > > > However, we can modify our implementation to adopt this change since it > > > brings about benefits overall. > > Ideally it would be great to have unified implementation, but we can define > > device specific value for CLK_NULL_RESERVE_ID by using ifdef directive. > How about > > ``` > __attribute__((const)) size_t __clk_null_reserve_id(); > #define CLK_NULL_RESERVE_ID __clk_null_reserve_id() > > ``` > I think the spec does not require it to be compile time constant. Then each > library can implement its own __clk_null_reserve_id() whereas the IR is > target independent. Or we only do this for SPIR and define it as target specific value for other targets. https://reviews.llvm.org/D32896 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
