[llvm] [openmp] [OpenMP][DeviceRTL] Fix the chunked static distribution dropping iterations (PR #216117)

[Johannes Doerfert via llvm-commits]

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@@ -0,0 +1,75 @@
+// Chunked static distribution: thread T owns iterations [T*chunk, T*chunk+chunk)
+// within each block chunk. The index used to start each thread has to account
+// for the chunk, and the block chunk has to cover one chunk per thread.
+//
+// The entry is called directly because no C/C++ construct reaches it: clang
+// emits __kmpc_for_static_init_4, only flang emits this one.
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jdoerfert wrote:

Until someone finally changes clang's codegen :(

https://github.com/llvm/llvm-project/pull/216117