[Mlir-commits] [clang] [llvm] [mlir] [openmp] [OpenMP][offload] Cross-team reductions with variable number of teams (PR #195102)

[Johannes Doerfert]

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@@ -58,6 +58,10 @@ struct ConfigurationEnvironmentTy {
   int32_t MinTeams = -1;
   int32_t MaxTeams = -1;
   int32_t ReductionDataSize = 0;
+  // Reserved slot; new codegen writes 0 (plugin sizes the teams-reduction
+  // buffer from NumBlocks[0] at launch), but a non-zero value from older
+  // binaries is still honored as a compile-time upper bound on the number
+  // of teams.
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jdoerfert wrote:

I don't think this is accurate. ReductionBufferLength was never an upper bound on the number of teams. It was a way to limit the memory footprint of reductions. If we had more teams than slots, we used time sharing. Thus, the value given by older binaries should be meaningless at this point. Wdyt?

https://github.com/llvm/llvm-project/pull/195102