[flang-commits] [flang] [flang][MLIR] Hoist `do concurrent` nest bounds/steps outside the nest (PR #114020)

[Kareem Ergawy via flang-commits]

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@@ -2131,18 +2131,33 @@ class FirConverter : public Fortran::lower::AbstractConverter {
       llvm::SmallVectorImpl<const Fortran::parser::CompilerDirective *> &dirs) {
     assert(!incrementLoopNestInfo.empty() && "empty loop nest");
     mlir::Location loc = toLocation();
+
     for (IncrementLoopInfo &info : incrementLoopNestInfo) {
-      info.loopVariable =
-          genLoopVariableAddress(loc, *info.loopVariableSym, info.isUnordered);
-      mlir::Value lowerValue = genControlValue(info.lowerExpr, info);
-      mlir::Value upperValue = genControlValue(info.upperExpr, info);
-      bool isConst = true;
-      mlir::Value stepValue = genControlValue(
-          info.stepExpr, info, info.isStructured() ? nullptr : &isConst);
-      // Use a temp variable for unstructured loops with non-const step.
-      if (!isConst) {
-        info.stepVariable = builder->createTemporary(loc, stepValue.getType());
-        builder->create<fir::StoreOp>(loc, stepValue, info.stepVariable);
+      mlir::Value lowerValue;
+      mlir::Value upperValue;
+      mlir::Value stepValue;
+
+      {
+        mlir::OpBuilder::InsertionGuard guard(*builder);
+
+        // Set the IP before the first loop in the nest so that all nest bounds
+        // and step values are created outside the nest.
+        if (incrementLoopNestInfo[0].doLoop)
+          builder->setInsertionPoint(incrementLoopNestInfo[0].doLoop);
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ergawy wrote:

Thanks for pointing that out. Done.

https://github.com/llvm/llvm-project/pull/114020