[OPENMP][NVPTX]Improve code by using parallel level counter.

Summary:
Previously for the different purposes we need to get the active/common
parallel level and with full runtime we iterated over all the records to
calculate this level. Instead, we can used the warp-based parallel level
counters used in no-runtime mode.

Reviewers: grokos, gtbercea, kkwli0

Subscribers: guansong, jfb, jdoerfert, caomhin, openmp-commits

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D61395

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@359822 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 50 deletions

diff --git a/libomptarget/deviceRTLs/nvptx/src/libcall.cu b/libomptarget/deviceRTLs/nvptx/src/libcall.cu
index 26b0f4e..452463c 100644
--- a/libomptarget/deviceRTLs/nvptx/src/libcall.cu
+++ b/libomptarget/deviceRTLs/nvptx/src/libcall.cu
@@ -47,8 +47,7 @@ EXTERN void omp_set_num_threads(int num) {
 EXTERN int omp_get_num_threads(void) {
   bool isSPMDExecutionMode = isSPMDMode();
   int tid = GetLogicalThreadIdInBlock(isSPMDExecutionMode);
-  int rc =
-      GetNumberOfOmpThreads(tid, isSPMDExecutionMode, isRuntimeUninitialized());
+  int rc = GetNumberOfOmpThreads(tid, isSPMDExecutionMode);
   PRINT(LD_IO, "call omp_get_num_threads() return %d\n", rc);
   return rc;
 }
@@ -83,7 +82,7 @@ EXTERN int omp_get_thread_limit(void) {
 EXTERN int omp_get_thread_num() {
   bool isSPMDExecutionMode = isSPMDMode();
   int tid = GetLogicalThreadIdInBlock(isSPMDExecutionMode);
-  int rc = GetOmpThreadId(tid, isSPMDExecutionMode, isRuntimeUninitialized());
+  int rc = GetOmpThreadId(tid, isSPMDExecutionMode);
   PRINT(LD_IO, "call omp_get_thread_num() returns %d\n", rc);
   return rc;
 }
@@ -95,18 +94,7 @@ EXTERN int omp_get_num_procs(void) {
 }
 
 EXTERN int omp_in_parallel(void) {
-  int rc = 0;
-  if (isRuntimeUninitialized()) {
-    ASSERT0(LT_FUSSY, isSPMDMode(),
-            "Expected SPMD mode only with uninitialized runtime.");
-    rc = 1;  // SPMD mode is always in parallel.
-  } else {
-    omptarget_nvptx_TaskDescr *currTaskDescr =
-        getMyTopTaskDescriptor(isSPMDMode());
-    if (currTaskDescr->InParallelRegion()) {
-      rc = 1;
-    }
-  }
+  int rc = parallelLevel[GetWarpId()] > OMP_ACTIVE_PARALLEL_LEVEL ? 1 : 0;
   PRINT(LD_IO, "call omp_in_parallel() returns %d\n", rc);
   return rc;
 }
@@ -155,46 +143,13 @@ EXTERN int omp_get_max_active_levels(void) {
 }
 
 EXTERN int omp_get_level(void) {
-  if (isRuntimeUninitialized()) {
-    ASSERT0(LT_FUSSY, isSPMDMode(),
-            "Expected SPMD mode only with uninitialized runtime.");
-    // parallelLevel starts from 0, need to add 1 for correct level.
-    return parallelLevel[GetWarpId()] + 1;
-  }
-  int level = 0;
-  omptarget_nvptx_TaskDescr *currTaskDescr =
-      getMyTopTaskDescriptor(isSPMDMode());
-  ASSERT0(LT_FUSSY, currTaskDescr,
-          "do not expect fct to be called in a non-active thread");
-  do {
-    if (currTaskDescr->IsParallelConstruct()) {
-      level++;
-    }
-    currTaskDescr = currTaskDescr->GetPrevTaskDescr();
-  } while (currTaskDescr);
+  int level = parallelLevel[GetWarpId()] & (OMP_ACTIVE_PARALLEL_LEVEL - 1);
   PRINT(LD_IO, "call omp_get_level() returns %d\n", level);
   return level;
 }
 
 EXTERN int omp_get_active_level(void) {
-  if (isRuntimeUninitialized()) {
-    ASSERT0(LT_FUSSY, isSPMDMode(),
-            "Expected SPMD mode only with uninitialized runtime.");
-    return 1;
-  }
-  int level = 0; // no active level parallelism
-  omptarget_nvptx_TaskDescr *currTaskDescr =
-      getMyTopTaskDescriptor(isSPMDMode());
-  ASSERT0(LT_FUSSY, currTaskDescr,
-          "do not expect fct to be called in a non-active thread");
-  do {
-    if (currTaskDescr->ThreadsInTeam() > 1) {
-      // has a parallel with more than one thread in team
-      level = 1;
-      break;
-    }
-    currTaskDescr = currTaskDescr->GetPrevTaskDescr();
-  } while (currTaskDescr);
+  int level = parallelLevel[GetWarpId()] > OMP_ACTIVE_PARALLEL_LEVEL ? 1 : 0;
   PRINT(LD_IO, "call omp_get_active_level() returns %d\n", level)
   return level;
 }