1 files changed, 64 insertions, 0 deletions
diff --git a/js/src/jit/AliasAnalysis.h b/js/src/jit/AliasAnalysis.h
new file mode 100644
index 0000000000..49ddaee47c
--- /dev/null
+++ b/js/src/jit/AliasAnalysis.h
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jit_AliasAnalysis_h
+#define jit_AliasAnalysis_h
+
+#include "jit/MIR.h"
+#include "jit/MIRGraph.h"
+
+namespace js {
+namespace jit {
+
+class LoopAliasInfo;
+
+class AliasAnalysis {
+  MIRGenerator* mir;
+  MIRGraph& graph_;
+  LoopAliasInfo* loop_;
+
+  void spewDependencyList();
+
+  TempAllocator& alloc() const { return graph_.alloc(); }
+
+ public:
+  AliasAnalysis(MIRGenerator* mir, MIRGraph& graph)
+      : mir(mir), graph_(graph), loop_(nullptr) {}
+
+  [[nodiscard]] bool analyze();
+};
+
+// Iterates over the flags in an AliasSet.
+class AliasSetIterator {
+ private:
+  uint32_t flags;
+  unsigned pos;
+
+ public:
+  explicit AliasSetIterator(AliasSet set) : flags(set.flags()), pos(0) {
+    while (flags && (flags & 1) == 0) {
+      flags >>= 1;
+      pos++;
+    }
+  }
+  AliasSetIterator& operator++(int) {
+    do {
+      flags >>= 1;
+      pos++;
+    } while (flags && (flags & 1) == 0);
+    return *this;
+  }
+  explicit operator bool() const { return !!flags; }
+  unsigned operator*() const {
+    MOZ_ASSERT(pos < AliasSet::NumCategories);
+    return pos;
+  }
+};
+
+}  // namespace jit
+}  // namespace js
+
+#endif /* jit_AliasAnalysis_h */