[Mlir-commits] [mlir] [mlir][gpu] Add address space modifier to gpu.barrier (PR #177425)

[Alan Li]

================
@@ -1472,18 +1472,45 @@ LogicalResult RotateOp::verify() {
 /// Remove gpu.barrier after gpu.barrier, the threads are already synchronized!
 static LogicalResult eraseRedundantGpuBarrierOps(BarrierOp op,
                                                  PatternRewriter &rewriter) {
-  if (isa_and_nonnull<BarrierOp>(op->getNextNode())) {
-    rewriter.eraseOp(op);
-    return success();
+  auto nextOp = dyn_cast_or_null<BarrierOp>(op->getNextNode());
+  if (!nextOp)
+    return failure();
+
+  std::optional<ArrayAttr> thisMemfence = op.getAddressSpaces();
+  std::optional<ArrayAttr> nextMemfence = nextOp.getAddressSpaces();
+
+  if (thisMemfence) {
+    rewriter.modifyOpInPlace(op, [&]() {
+      if (!nextMemfence) {
+        op.removeAddressSpacesAttr();
+        return;
+      }
+      // Fast path - mergge where the two barriers fence the same spaces.
----------------
lialan wrote:

```suggestion
      // Fast path - merge where the two barriers fence the same spaces.
```

https://github.com/llvm/llvm-project/pull/177425