[llvm-branch-commits] [mlir] [MLIR][OpenMP] Support target SPMD (PR #127821)

[Michael Kruse via llvm-branch-commits]

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@@ -4081,11 +4075,26 @@ static void extractHostEvalClauses(omp::TargetOp targetOp, Value &numThreads,
               llvm_unreachable("unsupported host_eval use");
           })
           .Case([&](omp::LoopNestOp loopOp) {
-            // TODO: Extract bounds and step values. Currently, this cannot be
-            // reached because translation would have been stopped earlier as a
-            // result of `checkImplementationStatus` detecting and reporting
-            // this situation.
-            llvm_unreachable("unsupported host_eval use");
+            auto processBounds =
+                [&](OperandRange opBounds,
+                    llvm::SmallVectorImpl<Value> *outBounds) -> bool {
+              bool found = false;
+              for (auto [i, lb] : llvm::enumerate(opBounds)) {
+                if (lb == blockArg) {
+                  found = true;
+                  if (outBounds)
+                    (*outBounds)[i] = hostEvalVar;
+                }
+              }
+              return found;
+            };
+            bool found =
+                processBounds(loopOp.getLoopLowerBounds(), lowerBounds);
+            found = processBounds(loopOp.getLoopUpperBounds(), upperBounds) ||
+                    found;
+            found = processBounds(loopOp.getLoopSteps(), steps) || found;
+            if (!found)
+              llvm_unreachable("unsupported host_eval use");
----------------
Meinersbur wrote:

```suggestion
            (void)found;
            assert(found && "unsupported host_eval use");
```

https://github.com/llvm/llvm-project/pull/127821