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Issue 7308004: Extract string->double and double->string conversions for use in the preparser. (Closed) Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge
Patch Set: git utd Created 9 years, 5 months ago
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1 // Copyright 2010 the V8 project authors. All rights reserved. 1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without 2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are 3 // modification, are permitted provided that the following conditions are
4 // met: 4 // met:
5 // 5 //
6 // * Redistributions of source code must retain the above copyright 6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer. 7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above 8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following 9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided 10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution. 11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its 12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived 13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission. 14 // from this software without specific prior written permission.
15 // 15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 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. 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 27
28 #include "v8.h" 28 #include "../include/v8stdint.h"
29 29 #include "globals.h"
30 #include "checks.h"
30 #include "diy-fp.h" 31 #include "diy-fp.h"
31 32
32 namespace v8 { 33 namespace v8 {
33 namespace internal { 34 namespace internal {
34 35
35 void DiyFp::Multiply(const DiyFp& other) { 36 void DiyFp::Multiply(const DiyFp& other) {
36 // Simply "emulates" a 128 bit multiplication. 37 // Simply "emulates" a 128 bit multiplication.
37 // However: the resulting number only contains 64 bits. The least 38 // However: the resulting number only contains 64 bits. The least
38 // significant 64 bits are only used for rounding the most significant 64 39 // significant 64 bits are only used for rounding the most significant 64
39 // bits. 40 // bits.
40 const uint64_t kM32 = 0xFFFFFFFFu; 41 const uint64_t kM32 = 0xFFFFFFFFu;
41 uint64_t a = f_ >> 32; 42 uint64_t a = f_ >> 32;
42 uint64_t b = f_ & kM32; 43 uint64_t b = f_ & kM32;
43 uint64_t c = other.f_ >> 32; 44 uint64_t c = other.f_ >> 32;
44 uint64_t d = other.f_ & kM32; 45 uint64_t d = other.f_ & kM32;
45 uint64_t ac = a * c; 46 uint64_t ac = a * c;
46 uint64_t bc = b * c; 47 uint64_t bc = b * c;
47 uint64_t ad = a * d; 48 uint64_t ad = a * d;
48 uint64_t bd = b * d; 49 uint64_t bd = b * d;
49 uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32); 50 uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32);
50 // By adding 1U << 31 to tmp we round the final result. 51 // By adding 1U << 31 to tmp we round the final result.
51 // Halfway cases will be round up. 52 // Halfway cases will be round up.
52 tmp += 1U << 31; 53 tmp += 1U << 31;
53 uint64_t result_f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32); 54 uint64_t result_f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32);
54 e_ += other.e_ + 64; 55 e_ += other.e_ + 64;
55 f_ = result_f; 56 f_ = result_f;
56 } 57 }
57 58
58 } } // namespace v8::internal 59 } } // namespace v8::internal
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