[Libclc-dev] [PATCH 1/2] atomic: Add generic bitcode implementation of atomic_max

[Matt Arsenault]

On Sep 8, 2014, at 2:13 PM, Aaron Watry <awatry at gmail.com> wrote:

> On Mon, Sep 8, 2014 at 12:12 PM, Matt Arsenault <arsenm2 at gmail.com> wrote:
>> 
>> On Sep 8, 2014, at 12:52 PM, Aaron Watry <awatry at gmail.com> wrote:
>> 
>>> From CL v1.2, Section 6.12.11:
>>> int atomic_max (volatile __global int *p, int val)
>>> unsigned int atomic_max (volatile __global unsigned int *p, unsigned int val)
>>> int atomic_max (volatile __local int *p, int val)
>>> unsigned int atomic_max (volatile __local unsigned int *p, unsigned int val)
>>> 
>>> I'm assuming that the pointer declaration as volatile should translate
>>> directly to the statement in the bitcode.  Let me know if you think I
>>> mis-understood that.  If that's the case, then we also need to fix the
>>> atomic_add and atomic_sub functions.
>> 
>> Yes, that’s how I would interpret it.
>>> 
>>> And yes, there's a note that the atom_* functions from CL 1.0 are
>>> still supported. Those functions do NOT define the pointers as
>>> volatile.
>> 
>> Yes, the sets of atomic functions are separate. It looks like currently atom_add is defined to be the same as atomic_add
>> 
> 
> I'd tend to agree with that statement.
> 
> Do you want any changes to this patch, or are we good?

It’s fine, although it would make sense to add both the atomic_ and atom_ versions at the same time


> 
> I'm currently trying to get atomic_max done because cppamp-driver-ng
> requires it, but eventually I'll probably get around to adding the
> other missing atomic_* functions and then the wrappers from CL1.0
> atom_* functions.
> 
> --Aaron
> 
>> 
>> 
>>> 
>>> --Aaron
>>> 
>>> --Aaron
>>> 
>>> 
>>> On Mon, Sep 8, 2014 at 11:41 AM, Matt Arsenault <arsenm2 at gmail.com> wrote:
>>>> 
>>>> On Sep 8, 2014, at 12:31 PM, Aaron Watry <awatry at gmail.com> wrote:
>>>> 
>>>>> Not used yet...
>>>>> 
>>>>> Signed-off-by: Aaron Watry <awatry at gmail.com>
>>>>> ---
>>>>> generic/include/clc/atomic/atomic_max.h |  3 +++
>>>>> generic/include/clc/clc.h               |  1 +
>>>>> generic/lib/atomic/atomic_impl.ll       | 12 ++++++++++++
>>>>> 3 files changed, 16 insertions(+)
>>>>> create mode 100644 generic/include/clc/atomic/atomic_max.h
>>>>> 
>>>>> diff --git a/generic/include/clc/atomic/atomic_max.h b/generic/include/clc/atomic/atomic_max.h
>>>>> new file mode 100644
>>>>> index 0000000..30dc180
>>>>> --- /dev/null
>>>>> +++ b/generic/include/clc/atomic/atomic_max.h
>>>>> @@ -0,0 +1,3 @@
>>>>> +#define __CLC_FUNCTION atomic_max
>>>>> +#include <clc/atomic/atomic_decl.inc>
>>>>> +#undef __CLC_FUNCTION
>>>>> diff --git a/generic/include/clc/clc.h b/generic/include/clc/clc.h
>>>>> index b8c1cb9..b492c54 100644
>>>>> --- a/generic/include/clc/clc.h
>>>>> +++ b/generic/include/clc/clc.h
>>>>> @@ -143,6 +143,7 @@
>>>>> #include <clc/atomic/atomic_add.h>
>>>>> #include <clc/atomic/atomic_dec.h>
>>>>> #include <clc/atomic/atomic_inc.h>
>>>>> +#include <clc/atomic/atomic_max.h>
>>>>> #include <clc/atomic/atomic_sub.h>
>>>>> 
>>>>> /* cl_khr_global_int32_base_atomics Extension Functions */
>>>>> diff --git a/generic/lib/atomic/atomic_impl.ll b/generic/lib/atomic/atomic_impl.ll
>>>>> index 9df5b9f..4e228e8 100644
>>>>> --- a/generic/lib/atomic/atomic_impl.ll
>>>>> +++ b/generic/lib/atomic/atomic_impl.ll
>>>>> @@ -10,6 +10,18 @@ entry:
>>>>> ret i32 %0
>>>>> }
>>>>> 
>>>>> +define i32 @__clc_atomic_max_addr1(i32 addrspace(1)* nocapture %ptr, i32 %value) nounwind alwaysinline {
>>>>> +entry:
>>>>> +  %0 = atomicrmw volatile max i32 addrspace(1)* %ptr, i32 %value seq_cst
>>>>> +  ret i32 %0
>>>>> +}
>>>> 
>>>> Why is it necessary to mark these with volatile (though I never remember whether it’s the atom_* or atomic_* functions which is supposed to be volatile)
>>>> 
>>>> 
>>>>> +
>>>>> +define i32 @__clc_atomic_max_addr3(i32 addrspace(3)* nocapture %ptr, i32 %value) nounwind alwaysinline {
>>>>> +entry:
>>>>> +  %0 = atomicrmw volatile max i32 addrspace(3)* %ptr, i32 %value seq_cst
>>>>> +  ret i32 %0
>>>>> +}
>>>>> +
>>>>> define i32 @__clc_atomic_sub_addr1(i32 addrspace(1)* nocapture %ptr, i32 %value) nounwind alwaysinline {
>>>>> entry:
>>>>> %0 = atomicrmw volatile sub i32 addrspace(1)* %ptr, i32 %value seq_cst
>>>>> --
>>>>> 1.9.1
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> Libclc-dev mailing list
>>>>> Libclc-dev at pcc.me.uk
>>>>> http://www.pcc.me.uk/cgi-bin/mailman/listinfo/libclc-dev

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