Hi Tom, hi Richard, hello all,
@Richard: does it look okay from the ME side?
@Tom: Can you check which IFN_GOMP_SIMT should be
excluded with -ftracer?
Pre-remark, I do not know much about SIMT – except that they
only appear with nvptx and somehow relate to lanes on the
GPU.
In any case, as the testcase libgomp.fortran/pr66199-5.f90 shows,
if a basic block with GOMP_SIMT_VOTE_ANY in it is duplicated,
which happens via -ftracer for this testcase, the result is wrong.
The testcase ignores all the loop work but via "lastprivate" takes
the upper loop bound (as assigned to the loop indices); instead of
the expected 32*32 = 1024, either some number (like 4 or very large
or negative) is returned.
While GOMP_SIMT_VOTE_ANY fixes the issue for this testcase, I
have the feeling that at least GOMP_SIMT_LAST_LANE should be
not copied - but I might be wrong.
Tom: Do you think GOMP_SIMT_LAST_LANE should be removed from
that list – or any of the following added as well?
GOMP_USE_SIMT, GOMP_SIMT_ENTER, GOMP_SIMT_ENTER_ALLOC, GOMP_SIMT_EXIT,
GOMP_SIMT_VF, GOMP_SIMT_ORDERED_PRED, GOMP_SIMT_XCHG_BFLY,
GOMP_SIMT_XCHG_IDX
OK for mainline?
Tobias
-----------------
Mentor Graphics (Deutschland) GmbH, Arnulfstraße 201, 80634 München / Germany
Registergericht München HRB 106955, Geschäftsführer: Thomas Heurung, Alexander
Walter
gcc/tracer.c: Don't split BB with SIMT LANE [PR95654]
gcc/ChangeLog:
PR fortran/95654
* gimple.h (gimple_call_internal_gomp_simt): Add; return true
if call is IFN_GOMP_SIMT_LAST_LANE or IFN_GOMP_SIMT_VOTE_ANY.
* tracer.c (ignore_bb_p): Return true if the BB contains those simt ifn.
libgomp/ChangeLog:
PR fortran/95654
* testsuite/libgomp.fortran/pr66199-5.f90: Make stop codes unique.
gcc/gimple.h | 17 +++++++++++++++++
gcc/tracer.c | 12 ++++++++++++
libgomp/testsuite/libgomp.fortran/pr66199-5.f90 | 2 +-
3 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/gcc/gimple.h b/gcc/gimple.h
index 6cc7e66..e0cefc9 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -3021,6 +3021,23 @@ gimple_call_internal_unique_p (const gimple *gs)
return gimple_call_internal_unique_p (gc);
}
+/* Return true, if this internal gimple call is
+ either gomp_simt_last_lane or gomp_simt_vote_any. */
+
+static inline bool
+gimple_call_internal_gomp_simt (const gcall *gs)
+{
+ return gimple_call_internal_fn (gs) == IFN_GOMP_SIMT_LAST_LANE
+ || gimple_call_internal_fn (gs) == IFN_GOMP_SIMT_VOTE_ANY;
+}
+
+static inline bool
+gimple_call_internal_gomp_simt (const gimple *gs)
+{
+ const gcall *gc = GIMPLE_CHECK2<const gcall *> (gs);
+ return gimple_call_internal_gomp_simt (gc);
+}
+
/* Return true if GS is an internal function FN. */
static inline bool
diff --git a/gcc/tracer.c b/gcc/tracer.c
index 82ede72..6c02e79 100644
--- a/gcc/tracer.c
+++ b/gcc/tracer.c
@@ -37,6 +37,7 @@
#include "system.h"
#include "coretypes.h"
#include "backend.h"
+#include "target.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
@@ -107,6 +108,17 @@ ignore_bb_p (const_basic_block bb)
&& gimple_call_internal_unique_p (g))
return true;
}
+ if (targetm.have_omp_simt_lane ())
+ for (gimple_stmt_iterator gsi = gsi_start_bb (CONST_CAST_BB (bb));
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gimple *g = gsi_stmt (gsi);
+ if (is_gimple_call (g)
+ && gimple_call_internal_p (g)
+ && gimple_call_internal_gomp_simt (g))
+ return true;
+ }
return false;
}
diff --git a/libgomp/testsuite/libgomp.fortran/pr66199-5.f90 b/libgomp/testsuite/libgomp.fortran/pr66199-5.f90
index 9482f08..2627a81 100644
--- a/libgomp/testsuite/libgomp.fortran/pr66199-5.f90
+++ b/libgomp/testsuite/libgomp.fortran/pr66199-5.f90
@@ -67,5 +67,5 @@ program main
if (f1 (0, 1024) /= 1024) stop 1
if (f2 (0, 1024, 17) /= 1024 + (17 + 5 * 1023)) stop 2
if (f3 (0, 32, 0, 32) /= 64) stop 3
- if (f4 (0, 32, 0, 32) /= 64) stop 3
+ if (f4 (0, 32, 0, 32) /= 64) stop 4
end
