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+/* -*- 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_TrialInlining_h
+#define jit_TrialInlining_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "jstypes.h"
+#include "NamespaceImports.h"
+
+#include "gc/Barrier.h"
+#include "jit/CacheIR.h"
+#include "jit/ICStubSpace.h"
+#include "js/RootingAPI.h"
+#include "js/TypeDecls.h"
+#include "js/UniquePtr.h"
+#include "js/Vector.h"
+#include "vm/JSScript.h"
+
+/*
+ * [SMDOC] Trial Inlining
+ *
+ * WarpBuilder relies on transpiling CacheIR. When inlining scripted
+ * functions in WarpBuilder, we want our ICs to be as monomorphic as
+ * possible. Functions with multiple callers complicate this. An IC in
+ * such a function might be monomorphic for any given caller, but
+ * polymorphic overall. This make the input to WarpBuilder less precise.
+ *
+ * To solve this problem, we do trial inlining. During baseline
+ * execution, we identify call sites for which it would be useful to
+ * have more precise inlining data. For each such call site, we
+ * allocate a fresh ICScript and replace the existing call IC with a
+ * new specialized IC that invokes the callee using the new
+ * ICScript. Other callers of the callee will continue using the
+ * default ICScript. When we eventually Warp-compile the script, we
+ * can generate code for the callee using the IC information in our
+ * private ICScript, which is specialized for its caller.
+ *
+ * The same approach can be used to inline recursively.
+ */
+
+class JS_PUBLIC_API JSTracer;
+struct JS_PUBLIC_API JSContext;
+
+class JSFunction;
+
+namespace JS {
+class Zone;
+}
+
+namespace js {
+
+class BytecodeLocation;
+
+namespace jit {
+
+class BaselineFrame;
+class CacheIRWriter;
+class ICCacheIRStub;
+class ICEntry;
+class ICFallbackStub;
+class ICScript;
+
+/*
+ * An InliningRoot is owned by a JitScript. In turn, it owns the set
+ * of ICScripts that are candidates for being inlined in that JitScript.
+ */
+class InliningRoot {
+ public:
+  explicit InliningRoot(JSContext* cx, JSScript* owningScript)
+      : owningScript_(owningScript),
+        inlinedScripts_(cx),
+        totalBytecodeSize_(owningScript->length()) {}
+
+  JitScriptICStubSpace* jitScriptStubSpace() { return &jitScriptStubSpace_; }
+
+  void trace(JSTracer* trc);
+
+  bool addInlinedScript(js::UniquePtr<ICScript> icScript);
+
+  uint32_t numInlinedScripts() const { return inlinedScripts_.length(); }
+
+  void purgeOptimizedStubs(Zone* zone);
+  void resetWarmUpCounts(uint32_t count);
+
+  JSScript* owningScript() const { return owningScript_; }
+
+  size_t totalBytecodeSize() const { return totalBytecodeSize_; }
+
+  void addToTotalBytecodeSize(size_t size) { totalBytecodeSize_ += size; }
+
+ private:
+  JitScriptICStubSpace jitScriptStubSpace_ = {};
+  HeapPtr<JSScript*> owningScript_;
+  js::Vector<js::UniquePtr<ICScript>> inlinedScripts_;
+
+  // Bytecode size of outer script and all inlined scripts.
+  size_t totalBytecodeSize_;
+};
+
+class InlinableOpData {
+ public:
+  JSFunction* target = nullptr;
+  ICScript* icScript = nullptr;
+  const uint8_t* endOfSharedPrefix = nullptr;
+};
+
+class InlinableCallData : public InlinableOpData {
+ public:
+  ObjOperandId calleeOperand;
+  CallFlags callFlags;
+};
+
+class InlinableGetterData : public InlinableOpData {
+ public:
+  ValOperandId receiverOperand;
+  bool sameRealm = false;
+};
+
+class InlinableSetterData : public InlinableOpData {
+ public:
+  ObjOperandId receiverOperand;
+  ValOperandId rhsOperand;
+  bool sameRealm = false;
+};
+
+mozilla::Maybe<InlinableOpData> FindInlinableOpData(ICCacheIRStub* stub,
+                                                    BytecodeLocation loc);
+
+mozilla::Maybe<InlinableCallData> FindInlinableCallData(ICCacheIRStub* stub);
+mozilla::Maybe<InlinableGetterData> FindInlinableGetterData(
+    ICCacheIRStub* stub);
+mozilla::Maybe<InlinableSetterData> FindInlinableSetterData(
+    ICCacheIRStub* stub);
+
+enum class TrialInliningDecision {
+  NoInline,
+  Inline,
+  MonomorphicInline,
+};
+
+class MOZ_RAII TrialInliner {
+ public:
+  TrialInliner(JSContext* cx, HandleScript script, ICScript* icScript)
+      : cx_(cx), script_(script), icScript_(icScript) {}
+
+  JSContext* cx() { return cx_; }
+
+  [[nodiscard]] bool tryInlining();
+  [[nodiscard]] bool maybeInlineCall(ICEntry& entry, ICFallbackStub* fallback,
+                                     BytecodeLocation loc);
+  [[nodiscard]] bool maybeInlineGetter(ICEntry& entry, ICFallbackStub* fallback,
+                                       BytecodeLocation loc, CacheKind kind);
+  [[nodiscard]] bool maybeInlineSetter(ICEntry& entry, ICFallbackStub* fallback,
+                                       BytecodeLocation loc, CacheKind kind);
+
+  static bool canInline(JSFunction* target, HandleScript caller,
+                        BytecodeLocation loc);
+
+ private:
+  ICCacheIRStub* maybeSingleStub(const ICEntry& entry);
+  void cloneSharedPrefix(ICCacheIRStub* stub, const uint8_t* endOfPrefix,
+                         CacheIRWriter& writer);
+  ICScript* createInlinedICScript(JSFunction* target, BytecodeLocation loc);
+  [[nodiscard]] bool replaceICStub(ICEntry& entry, ICFallbackStub* fallback,
+                                   CacheIRWriter& writer, CacheKind kind);
+
+  TrialInliningDecision getInliningDecision(JSFunction* target,
+                                            ICCacheIRStub* stub,
+                                            BytecodeLocation loc);
+
+  InliningRoot* getOrCreateInliningRoot();
+  InliningRoot* maybeGetInliningRoot() const;
+  size_t inliningRootTotalBytecodeSize() const;
+
+  JSContext* cx_;
+  HandleScript script_;
+  ICScript* icScript_;
+};
+
+bool DoTrialInlining(JSContext* cx, BaselineFrame* frame);
+
+}  // namespace jit
+}  // namespace js
+
+#endif /* jit_TrialInlining_h */