1.. _omp170: 2 3OpenMP runtime call <call> deduplicated. [OMP170] 4==================================================================== 5 6This optimization remark indicates that a call to an OpenMP runtime call was 7replaced with the result of an existing one. This occurs when the compiler knows 8that the result of a runtime call is immutable. Removing duplicate calls is done 9by replacing all calls to that function with the result of the first call. This 10cannot be done automatically by the compiler because the implementations of the 11OpenMP runtime calls live in a separate library the compiler cannot see. 12 13Example 14------- 15 16This optimization will trigger for known OpenMP runtime calls whose return value 17will not change. 18 19.. code-block:: c++ 20 21 void foo(int N) { 22 double *A = malloc(N * omp_get_thread_limit()); 23 double *B = malloc(N * omp_get_thread_limit()); 24 25 #pragma omp parallel 26 work(&A[omp_get_thread_num() * N]); 27 #pragma omp parallel 28 work(&B[omp_get_thread_num() * N]); 29 } 30 31.. code-block:: console 32 33 $ clang -fopenmp -O2 -Rpass=openmp-opt omp170.c 34 ompi170.c:2:26: remark: OpenMP runtime call omp_get_thread_limit deduplicated. [OMP170] 35 double *A = malloc(N * omp_get_thread_limit()); 36 ^ 37 38Diagnostic Scope 39---------------- 40 41OpenMP optimization remark. 42