tor-browser

The Tor Browser
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CacheIRHealth.h (4484B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * vim: set ts=8 sts=2 et sw=2 tw=80:
      3 * This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef jit_CacheIRHealth_h
      8 #define jit_CacheIRHealth_h
      9 
     10 #ifdef JS_CACHEIR_SPEW
     11 
     12 #  include "mozilla/Sprintf.h"
     13 
     14 #  include "NamespaceImports.h"
     15 
     16 #  include "jit/CacheIR.h"
     17 #  include "js/TypeDecls.h"
     18 
     19 enum class JSOp : uint8_t;
     20 
     21 namespace js {
     22 
     23 class AutoStructuredSpewer;
     24 
     25 namespace jit {
     26 
     27 class ICEntry;
     28 class ICStub;
     29 class ICCacheIRStub;
     30 class ICFallbackStub;
     31 
     32 // [SMDOC] CacheIR Health Report
     33 //
     34 // The goal of CacheIR health report is to make the costlier
     35 // CacheIR stubs more apparent and easier to diagnose.
     36 // This is done by using the scores assigned to different CacheIROps in
     37 // CacheIROps.yaml (see the description of cost_estimate in the
     38 // aforementioned file for how these scores are determined), summing
     39 // the score of each op generated for a particular stub together, and displaying
     40 // this score for each stub in an inline cache. The higher the total stub score,
     41 // the more expensive the stub is.
     42 //
     43 // There are a few ways to generate a health report for a script:
     44 // 1. Simply running a JS program with the evironment variable
     45 //    SPEW=CacheIRHealthReport. We generate a health report for a script
     46 //    whenever we reach the trial inlining threshold.
     47 //      ex) SPEW=CacheIRHealthReport dist/bin/js jsprogram.js
     48 // 2. In the shell you can call cacheIRHealthReport() with no arguments and a
     49 // report
     50 //    will be generated for all scripts in the current zone.
     51 //      ex) cacheIRHealthReport()
     52 // 3. You may also call cacheIRHealthReport() on a particular function to see
     53 // the
     54 //    health report associated with that function's script.
     55 //      ex) cacheIRHealthReport(foo)
     56 //
     57 // Once you have generated a health report, you may go to
     58 // https://mozilla-spidermonkey.github.io/cacheirhealthreport/ to visualize the
     59 // data and aid in understanding what may be going wrong with the CacheIR for a
     60 // particular stub. For more information about the tool and why a particular
     61 // script, inline cache entry, or stub is unhappy go to:
     62 // https://mozilla-spidermonkey.github.io/cacheirhealthreport/info.html
     63 //
     64 enum SpewContext : uint8_t { Shell, Transition, TrialInlining };
     65 
     66 class CacheIRHealth {
     67  enum Happiness : uint8_t { Sad, MediumSad, MediumHappy, Happy };
     68 
     69  // Get happiness from health score.
     70  Happiness determineStubHappiness(uint32_t stubHealthScore);
     71  // Health of an individual stub.
     72  Happiness spewStubHealth(AutoStructuredSpewer& spew, ICCacheIRStub* stub);
     73  // If there is more than just a fallback stub in an IC Entry, then additional
     74  // information about the IC entry.
     75  bool spewNonFallbackICInformation(AutoStructuredSpewer& spew, JSContext* cx,
     76                                    ICStub* firstStub,
     77                                    Happiness* entryHappiness);
     78  // Health of all the stubs in an individual CacheIR Entry.
     79  bool spewICEntryHealth(AutoStructuredSpewer& spew, JSContext* cx,
     80                         HandleScript script, ICEntry* entry,
     81                         ICFallbackStub* fallback, jsbytecode* pc, JSOp op,
     82                         Happiness* entryHappiness);
     83  // Spews first and last property name for each shape checked by
     84  // GuardShape in the stub.
     85  void spewShapeInformation(AutoStructuredSpewer& spew, JSContext* cx,
     86                            ICStub* stub);
     87  // Returns the BaseScript of a Shape if available.
     88  BaseScript* maybeExtractBaseScript(JSContext* cx, Shape* shape);
     89 
     90 public:
     91  // Spews the final hit count for scripts where we care about its final hit
     92  // count.
     93  void spewScriptFinalWarmUpCount(JSContext* cx, const char* filename,
     94                                  JSScript* script, uint32_t warmUpCount);
     95  // Spew the health of a particular ICEntry only.
     96  void healthReportForIC(JSContext* cx, ICEntry* entry,
     97                         ICFallbackStub* fallback, HandleScript script,
     98                         SpewContext context);
     99  // If a JitScript exists, spew the health of all ICEntries that exist
    100  // for the specified script.
    101  void healthReportForScript(JSContext* cx, HandleScript script,
    102                             SpewContext context);
    103 };
    104 
    105 }  // namespace jit
    106 }  // namespace js
    107 
    108 #endif /* JS_CACHEIR_SPEW */
    109 #endif /* jit_CacheIRHealth_h */