[llvm-branch-commits] [flang] [flang][OpenMP] Map simple `do concurrent` loops to OpenMP host constructs (PR #127633)

[Sergio Afonso via llvm-branch-commits]

================
@@ -152,26 +231,136 @@ class DoConcurrentConversion : public mlir::OpConversionPattern<fir::DoLoopOp> {
 public:
   using mlir::OpConversionPattern<fir::DoLoopOp>::OpConversionPattern;
 
-  DoConcurrentConversion(mlir::MLIRContext *context, bool mapToDevice)
-      : OpConversionPattern(context), mapToDevice(mapToDevice) {}
+  DoConcurrentConversion(mlir::MLIRContext *context, bool mapToDevice,
+                         llvm::DenseSet<fir::DoLoopOp> &concurrentLoopsToSkip)
+      : OpConversionPattern(context), mapToDevice(mapToDevice),
+        concurrentLoopsToSkip(concurrentLoopsToSkip) {}
 
   mlir::LogicalResult
   matchAndRewrite(fir::DoLoopOp doLoop, OpAdaptor adaptor,
                   mlir::ConversionPatternRewriter &rewriter) const override {
-    looputils::LoopNest loopNest;
+    looputils::LoopNestToIndVarMap loopNest;
     bool hasRemainingNestedLoops =
         failed(looputils::collectLoopNest(doLoop, loopNest));
     if (hasRemainingNestedLoops)
       mlir::emitWarning(doLoop.getLoc(),
                         "Some `do concurent` loops are not perfectly-nested. "
                         "These will be serialized.");
 
-    // TODO This will be filled in with the next PRs that upstreams the rest of
-    // the ROCm implementaion.
+    mlir::IRMapping mapper;
+    genParallelOp(doLoop.getLoc(), rewriter, loopNest, mapper);
+    mlir::omp::LoopNestOperands loopNestClauseOps;
+    genLoopNestClauseOps(doLoop.getLoc(), rewriter, loopNest, mapper,
+                         loopNestClauseOps);
+
+    mlir::omp::LoopNestOp ompLoopNest =
+        genWsLoopOp(rewriter, loopNest.back().first, mapper, loopNestClauseOps,
+                    /*isComposite=*/mapToDevice);
----------------
skatrak wrote:

This will at the moment cause invalid MLIR to be produced (composite `omp.wsloop` with no other loop wrappers). We should probably emit a not yet implemented error if `mapToDevice=true` at the beginning of the function instead, unless you intend to merge host and target support at the same time.

https://github.com/llvm/llvm-project/pull/127633