js/src/jit/EdgeCaseAnalysis.cpp

   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 #include "jit/EdgeCaseAnalysis.h"
   8
   9 #include "jit/MIR.h"
  10 #include "jit/MIRGenerator.h"
  11 #include "jit/MIRGraph.h"
  12
  13 using namespace js;
  14 using namespace js::jit;
  15
  16 EdgeCaseAnalysis::EdgeCaseAnalysis(MIRGenerator* mir, MIRGraph& graph)
  17     : mir(mir), graph(graph) {}
  18
  19 bool EdgeCaseAnalysis::analyzeLate() {
  20   // Renumber definitions for NeedNegativeZeroCheck under
  21   // analyzeEdgeCasesBackward.
  22   uint32_t nextId = 0;
  23
  24   for (ReversePostorderIterator block(graph.rpoBegin());
  25        block != graph.rpoEnd(); block++) {
  26     for (MDefinitionIterator iter(*block); iter; iter++) {
  27       if (mir->shouldCancel("Analyze Late (first loop)")) {
  28         return false;
  29       }
  30
  31       iter->setId(nextId++);
  32       iter->analyzeEdgeCasesForward();
  33     }
  34     block->lastIns()->setId(nextId++);
  35   }
  36
  37   for (PostorderIterator block(graph.poBegin()); block != graph.poEnd();
  38        block++) {
  39     for (MInstructionReverseIterator riter(block->rbegin());
  40          riter != block->rend(); riter++) {
  41       if (mir->shouldCancel("Analyze Late (second loop)")) {
  42         return false;
  43       }
  44
  45       riter->analyzeEdgeCasesBackward();
  46     }
  47   }
  48
  49   return true;
  50 }