Пример #1
0
SSATmp* TraceBuilder::optimizeWork(IRInstruction* inst,
                                   const folly::Optional<IdomVector>& idoms) {
    // Since some of these optimizations inspect tracked state, we don't
    // perform any of them on non-main traces.
    if (m_savedTraces.size() > 0) return nullptr;

    static DEBUG_ONLY __thread int instNest = 0;
    if (debug) ++instNest;
    SCOPE_EXIT { if (debug) --instNest; };
DEBUG_ONLY auto indent = [&] { return std::string(instNest * 2, ' '); };

    FTRACE(1, "{}{}\n", indent(), inst->toString());

    // First pass of tracebuilder optimizations try to replace an
    // instruction based on tracked state before we do anything else.
    // May mutate the IRInstruction in place (and return nullptr) or
    // return an SSATmp*.
    if (SSATmp* preOpt = preOptimize(inst)) {
        FTRACE(1, "  {}preOptimize returned: {}\n",
               indent(), preOpt->inst()->toString());
        return preOpt;
    }
    if (inst->op() == Nop) return nullptr;

    // copy propagation on inst source operands
    copyProp(inst);

    SSATmp* result = nullptr;
    if (m_enableCse && inst->canCSE()) {
        result = cseLookup(inst, idoms);
        if (result) {
            // Found a dominating instruction that can be used instead of inst
            FTRACE(1, "  {}cse found: {}\n",
                   indent(), result->inst()->toString());
            assert(!inst->consumesReferences());
            if (inst->producesReference()) {
                // Replace with an IncRef
                FTRACE(1, "  {}cse of refcount-producing instruction\n", indent());
                return gen(IncRef, result);
            } else {
                return result;
            }
        }
    }

    if (m_enableSimplification) {
        result = m_simplifier.simplify(inst);
        if (result) {
            // Found a simpler instruction that can be used instead of inst
            FTRACE(1, "  {}simplification returned: {}\n",
                   indent(), result->inst()->toString());
            assert(inst->hasDst());
            return result;
        }
    }
    return nullptr;
}
Пример #2
0
SSATmp* TraceBuilder::optimizeWork(IRInstruction* inst) {
  static DEBUG_ONLY __thread int instNest = 0;
  if (debug) ++instNest;
  SCOPE_EXIT { if (debug) --instNest; };
  DEBUG_ONLY auto indent = [&] { return std::string(instNest * 2, ' '); };

  FTRACE(1, "{}{}\n", indent(), inst->toString());

  // First pass of tracebuilder optimizations try to replace an
  // instruction based on tracked state before we do anything else.
  // May mutate the IRInstruction in place (and return nullptr) or
  // return an SSATmp*.
  if (SSATmp* preOpt = preOptimize(inst)) {
    FTRACE(1, "  {}preOptimize returned: {}\n",
           indent(), preOpt->inst()->toString());
    return preOpt;
  }
  if (inst->op() == Nop) return nullptr;

  // copy propagation on inst source operands
  copyProp(inst);

  SSATmp* result = nullptr;
  if (m_enableCse && inst->canCSE()) {
    result = cseLookup(inst);
    if (result) {
      // Found a dominating instruction that can be used instead of inst
      FTRACE(1, "  {}cse found: {}\n",
             indent(), result->inst()->toString());
      return result;
    }
  }

  if (m_enableSimplification) {
    result = m_simplifier.simplify(inst);
    if (result) {
      // Found a simpler instruction that can be used instead of inst
      FTRACE(1, "  {}simplification returned: {}\n",
             indent(), result->inst()->toString());
      assert(inst->hasDst());
      return result;
    }
  }
  return nullptr;
}