js/src/jit/CacheIRHealth.h

   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 */