[ was: Re: [PATCH][omp, ftracer] Don't duplicate blocks in SIMT region ]
On 10/5/20 10:51 AM, Alexander Monakov wrote:
>> + The IFN_GOMP_SIMT_VOTE_ANY is currently part of such a group,
>> + so the same holds there, but it could be argued that the
>> + IFN_GOMP_SIMT_VOTE_ANY could be generated after that group,
>> + in which case it could be duplicated. */
> No, something like that cannot be argued, as VOTE_ANY may have data
> dependencies to storage that is deallocated by SIMT_EXIT. You seem to be
> claiming something that is simply not possible with the current design.
>
Fixed in patch below, committed.
Thanks,
- Tom
[omp, ftracer] Remove incorrect suggestion in ignore_bb_p
In commit ab3f4b27abe "[omp, ftracer] Don't duplicate blocks in SIMT region" I
added a comment in ignore_bb_p suggesting a reordering of SIMT_VOTE_ANY and
SIMT_EXIT, which is not possible since VOTE_ANY may have data dependencies to
storage that is deallocated by SIMT_EXIT.
I've now opened a PR (PR97291) to describe the problem the reordering was
intended to fix.
Remove the incorrect suggestion.
gcc/ChangeLog:
2020-10-05 Tom de Vries <tdevr...@suse.de>
* tracer.c (ignore_bb_p): Remove incorrect suggestion.
---
gcc/tracer.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/gcc/tracer.c b/gcc/tracer.c
index 5e51752d89f..5ee66511f8d 100644
--- a/gcc/tracer.c
+++ b/gcc/tracer.c
@@ -115,10 +115,8 @@ ignore_bb_p (const_basic_block bb)
/* An IFN_GOMP_SIMT_ENTER_ALLOC/IFN_GOMP_SIMT_EXIT call must be
duplicated as part of its group, or not at all.
- The IFN_GOMP_SIMT_VOTE_ANY is currently part of such a group,
- so the same holds there, but it could be argued that the
- IFN_GOMP_SIMT_VOTE_ANY could be generated after that group,
- in which case it could be duplicated. */
+ The IFN_GOMP_SIMT_VOTE_ANY is part of such a group, so the same holds
+ there. */
if (is_gimple_call (g)
&& (gimple_call_internal_p (g, IFN_GOMP_SIMT_ENTER_ALLOC)
|| gimple_call_internal_p (g, IFN_GOMP_SIMT_EXIT)
