aboutsummaryrefslogtreecommitdiffstats
path: root/src/3rdparty/double-conversion/diy-fp.cc
diff options
context:
space:
mode:
authorSimon Hausmann <simon.hausmann@digia.com>2013-04-15 11:34:00 +0200
committerSimon Hausmann <simon.hausmann@digia.com>2013-04-15 12:47:53 +0200
commit2cd8a90bd4d171ed2404822b6046455a94d4b6ed (patch)
treeed8eda56d54cb13d777be1cfa294c85ddd76e583 /src/3rdparty/double-conversion/diy-fp.cc
parent5bf33901429e64ab91f30037e25ec04aab4b4c11 (diff)
parentbec019b5fe35e1701c944eb340df458d5e3d1cdb (diff)
Merge branch 'master' of ssh://codereview.qt-project.org:29418/playground/v4vm into v4
This is the initial merge of the v4vm JS engine, designed specifically for QML. The engine is tested on Linux and Mac OS X, works on x86, x86-64 and ARM. Change-Id: I826b72cfa3d3575007b70d78604080582db568db Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Diffstat (limited to 'src/3rdparty/double-conversion/diy-fp.cc')
-rw-r--r--src/3rdparty/double-conversion/diy-fp.cc57
1 files changed, 57 insertions, 0 deletions
diff --git a/src/3rdparty/double-conversion/diy-fp.cc b/src/3rdparty/double-conversion/diy-fp.cc
new file mode 100644
index 0000000000..ddd1891b16
--- /dev/null
+++ b/src/3rdparty/double-conversion/diy-fp.cc
@@ -0,0 +1,57 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "diy-fp.h"
+#include "utils.h"
+
+namespace double_conversion {
+
+void DiyFp::Multiply(const DiyFp& other) {
+ // Simply "emulates" a 128 bit multiplication.
+ // However: the resulting number only contains 64 bits. The least
+ // significant 64 bits are only used for rounding the most significant 64
+ // bits.
+ const uint64_t kM32 = 0xFFFFFFFFU;
+ uint64_t a = f_ >> 32;
+ uint64_t b = f_ & kM32;
+ uint64_t c = other.f_ >> 32;
+ uint64_t d = other.f_ & kM32;
+ uint64_t ac = a * c;
+ uint64_t bc = b * c;
+ uint64_t ad = a * d;
+ uint64_t bd = b * d;
+ uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32);
+ // By adding 1U << 31 to tmp we round the final result.
+ // Halfway cases will be round up.
+ tmp += 1U << 31;
+ uint64_t result_f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32);
+ e_ += other.e_ + 64;
+ f_ = result_f;
+}
+
+} // namespace double_conversion