[Openmp-commits] [openmp] 05e2bc2 - [OpenMP] Ensure socket layer is not first in CPUID topology detection

[Jonathan Peyton via Openmp-commits]

Author: Jonathan Peyton
Date: 2023-07-06T12:35:34-05:00
New Revision: 05e2bc25e85a904e45663584167d575580834396

URL: https://github.com/llvm/llvm-project/commit/05e2bc25e85a904e45663584167d575580834396
DIFF: https://github.com/llvm/llvm-project/commit/05e2bc25e85a904e45663584167d575580834396.diff

LOG: [OpenMP] Ensure socket layer is not first in CPUID topology detection

* Return 0 length topology if socket layer is detected first
* Fix DEBUG ASSERT

Added: 
    

Modified: 
    openmp/runtime/src/kmp_affinity.cpp

Removed: 
    


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diff  --git a/openmp/runtime/src/kmp_affinity.cpp b/openmp/runtime/src/kmp_affinity.cpp
index 31e9a19c47fcd7..eead5bdfb9e4fa 100644
--- a/openmp/runtime/src/kmp_affinity.cpp
+++ b/openmp/runtime/src/kmp_affinity.cpp
@@ -2509,6 +2509,10 @@ __kmp_x2apicid_get_levels(int leaf,
     level++;
   } while (level_type != INTEL_LEVEL_TYPE_INVALID);
 
+  // Ensure the INTEL_LEVEL_TYPE_INVALID (Socket) layer isn't first
+  if (levels_index == 0 || levels[0].level_type == INTEL_LEVEL_TYPE_INVALID)
+    return 0;
+
   // Set the masks to & with apicid
   for (unsigned i = 0; i < levels_index; ++i) {
     if (levels[i].level_type != INTEL_LEVEL_TYPE_INVALID) {
@@ -2517,7 +2521,7 @@ __kmp_x2apicid_get_levels(int leaf,
       for (unsigned j = 0; j < i; ++j)
         levels[i].mask ^= levels[j].mask;
     } else {
-      KMP_DEBUG_ASSERT(levels_index > 0);
+      KMP_DEBUG_ASSERT(i > 0);
       levels[i].mask = (-1) << levels[i - 1].mask_width;
       levels[i].cache_mask = 0;
     }