LCOV - app.info - js/src/v8-dtoa/diy-fp.cc

LCOV - code coverage report
| Current view: | directory - js/src/v8-dtoa - diy-fp.cc (source / functions) |  | Found | Hit | Coverage |
| Test: | app.info | Lines: | 16 | 16 | 100.0 %
| Date: | 2012-04-07 | Functions: | 1 | 1 | 100.0 %

           1                 : // Copyright 2010 the V8 project authors. All rights reserved.
           2                 : // Redistribution and use in source and binary forms, with or without
           3                 : // modification, are permitted provided that the following conditions are
           4                 : // met:
           5                 : //
           6                 : //     * Redistributions of source code must retain the above copyright
           7                 : //       notice, this list of conditions and the following disclaimer.
           8                 : //     * Redistributions in binary form must reproduce the above
           9                 : //       copyright notice, this list of conditions and the following
          10                 : //       disclaimer in the documentation and/or other materials provided
          11                 : //       with the distribution.
          12                 : //     * Neither the name of Google Inc. nor the names of its
          13                 : //       contributors may be used to endorse or promote products derived
          14                 : //       from this software without specific prior written permission.
          15                 : //
          16                 : // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
          17                 : // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
          18                 : // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
          19                 : // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
          20                 : // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
          21                 : // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
          22                 : // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
          23                 : // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
          24                 : // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
          25                 : // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
          26                 : // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
          27                 :
          28                 : #include "v8.h"
          29                 :
          30                 : #include "diy-fp.h"
          31                 :
          32                 : namespace v8 {
          33                 : namespace internal {
          34                 :
          35          639021 : void DiyFp::Multiply(const DiyFp& other) {
          36                 :   // Simply "emulates" a 128 bit multiplication.
          37                 :   // However: the resulting number only contains 64 bits. The least
          38                 :   // significant 64 bits are only used for rounding the most significant 64
          39                 :   // bits.
          40          639021 :   const uint64_t kM32 = 0xFFFFFFFFu;
          41          639021 :   uint64_t a = f_ >> 32;
          42          639021 :   uint64_t b = f_ & kM32;
          43          639021 :   uint64_t c = other.f_ >> 32;
          44          639021 :   uint64_t d = other.f_ & kM32;
          45          639021 :   uint64_t ac = a * c;
          46          639021 :   uint64_t bc = b * c;
          47          639021 :   uint64_t ad = a * d;
          48          639021 :   uint64_t bd = b * d;
          49          639021 :   uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32);
          50                 :   // By adding 1U << 31 to tmp we round the final result.
          51                 :   // Halfway cases will be round up.
          52          639021 :   tmp += 1U << 31;
          53          639021 :   uint64_t result_f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32);
          54          639021 :   e_ += other.e_ + 64;
          55          639021 :   f_ = result_f;
          56          639021 : }
          57                 :
          58                 : } }  // namespace v8::internal

Generated by: LCOV version 1.7