[flang-commits] [flang] [Flang] Minloc elemental intrinsic lowering (PR #74828)

[David Green via flang-commits]

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@@ -659,6 +677,194 @@ mlir::LogicalResult VariableAssignBufferization::matchAndRewrite(
   return mlir::success();
 }
 
+// Look for assign(minloc(mask=elemental)) and generate the minloc loop with
+// inlined elemental and no extra temporaries.
+//  %e = hlfir.elemental %shape ({ ... })
+//  %m = hlfir.minloc %array mask %e
+//  hlfir.assign %m to %result
+//  hlfir.destroy %m
+class AssignMinMaxlocElementalConversion
+    : public mlir::OpRewritePattern<hlfir::AssignOp> {
+public:
+  using mlir::OpRewritePattern<hlfir::AssignOp>::OpRewritePattern;
+
+  mlir::LogicalResult
+  matchAndRewrite(hlfir::AssignOp assign,
+                  mlir::PatternRewriter &rewriter) const override {
+    auto minloc = assign.getOperand(0).getDefiningOp<hlfir::MinlocOp>();
+    if (!minloc || !minloc.getMask() || minloc.getDim() || minloc.getBack())
+      return rewriter.notifyMatchFailure(assign,
+                                         "Did not find minloc with kind");
+
+    auto elemental = minloc.getMask().getDefiningOp<hlfir::ElementalOp>();
+    if (!elemental || hlfir::elementalOpMustProduceTemp(elemental))
+      return rewriter.notifyMatchFailure(assign, "Did not find elemental");
+
+    mlir::Operation::user_range users = minloc->getUsers();
+    if (std::distance(users.begin(), users.end()) != 2)
+      return rewriter.notifyMatchFailure(assign, "Did not find minloc users");
+    auto destroy = mlir::dyn_cast<hlfir::DestroyOp>(
+        *users.begin() == minloc ? *++users.begin() : *users.begin());
+    if (!destroy)
+      return rewriter.notifyMatchFailure(assign, "Did not find destroy");
+
+    if (!checkForElementalEffectsBetween(elemental, assign, minloc.getArray(),
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davemgreen wrote:

With the latest version of the code this is hopefully getting fixed in #77899.

https://github.com/llvm/llvm-project/pull/74828