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diff --git a/js/src/jit/CacheIRHealth.h b/js/src/jit/CacheIRHealth.h
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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_CacheIRHealth_h
+#define jit_CacheIRHealth_h
+
+#ifdef JS_CACHEIR_SPEW
+
+#  include "mozilla/Sprintf.h"
+
+#  include "NamespaceImports.h"
+
+#  include "jit/CacheIR.h"
+#  include "js/TypeDecls.h"
+
+enum class JSOp : uint8_t;
+
+namespace js {
+
+class AutoStructuredSpewer;
+
+namespace jit {
+
+class ICEntry;
+class ICStub;
+class ICCacheIRStub;
+class ICFallbackStub;
+
+// [SMDOC] CacheIR Health Report
+//
+// The goal of CacheIR health report is to make the costlier
+// CacheIR stubs more apparent and easier to diagnose.
+// This is done by using the scores assigned to different CacheIROps in
+// CacheIROps.yaml (see the description of cost_estimate in the
+// aforementioned file for how these scores are determined), summing
+// the score of each op generated for a particular stub together, and displaying
+// this score for each stub in an inline cache. The higher the total stub score,
+// the more expensive the stub is.
+//
+// There are a few ways to generate a health report for a script:
+// 1. Simply running a JS program with the evironment variable
+//    SPEW=CacheIRHealthReport. We generate a health report for a script
+//    whenever we reach the trial inlining threshold.
+//      ex) SPEW=CacheIRHealthReport dist/bin/js jsprogram.js
+// 2. In the shell you can call cacheIRHealthReport() with no arguments and a
+// report
+//    will be generated for all scripts in the current zone.
+//      ex) cacheIRHealthReport()
+// 3. You may also call cacheIRHealthReport() on a particular function to see
+// the
+//    health report associated with that function's script.
+//      ex) cacheIRHealthReport(foo)
+//
+// Once you have generated a health report, you may go to
+// https://mozilla-spidermonkey.github.io/cacheirhealthreport/ to visualize the
+// data and aid in understanding what may be going wrong with the CacheIR for a
+// particular stub. For more information about the tool and why a particular
+// script, inline cache entry, or stub is unhappy go to:
+// https://mozilla-spidermonkey.github.io/cacheirhealthreport/info.html
+//
+enum SpewContext : uint8_t { Shell, Transition, TrialInlining };
+
+class CacheIRHealth {
+  enum Happiness : uint8_t { Sad, MediumSad, MediumHappy, Happy };
+
+  // Get happiness from health score.
+  Happiness determineStubHappiness(uint32_t stubHealthScore);
+  // Health of an individual stub.
+  Happiness spewStubHealth(AutoStructuredSpewer& spew, ICCacheIRStub* stub);
+  // If there is more than just a fallback stub in an IC Entry, then additional
+  // information about the IC entry.
+  bool spewNonFallbackICInformation(AutoStructuredSpewer& spew, JSContext* cx,
+                                    ICStub* firstStub,
+                                    Happiness* entryHappiness);
+  // Health of all the stubs in an individual CacheIR Entry.
+  bool spewICEntryHealth(AutoStructuredSpewer& spew, JSContext* cx,
+                         HandleScript script, ICEntry* entry,
+                         ICFallbackStub* fallback, jsbytecode* pc, JSOp op,
+                         Happiness* entryHappiness);
+  // Spews first and last property name for each shape checked by
+  // GuardShape in the stub.
+  void spewShapeInformation(AutoStructuredSpewer& spew, JSContext* cx,
+                            ICStub* stub);
+  // Returns the BaseScript of a Shape if available.
+  BaseScript* maybeExtractBaseScript(JSContext* cx, Shape* shape);
+
+ public:
+  // Spews the final hit count for scripts where we care about its final hit
+  // count.
+  void spewScriptFinalWarmUpCount(JSContext* cx, const char* filename,
+                                  JSScript* script, uint32_t warmUpCount);
+  // Spew the health of a particular ICEntry only.
+  void healthReportForIC(JSContext* cx, ICEntry* entry,
+                         ICFallbackStub* fallback, HandleScript script,
+                         SpewContext context);
+  // If a JitScript exists, spew the health of all ICEntries that exist
+  // for the specified script.
+  void healthReportForScript(JSContext* cx, HandleScript script,
+                             SpewContext context);
+};
+
+}  // namespace jit
+}  // namespace js
+
+#endif /* JS_CACHEIR_SPEW */
+#endif /* jit_CacheIRHealth_h */