Changeset 231347 in webkit for trunk/Source/JavaScriptCore/jit/BinarySwitch.cpp

Timestamp:

May 3, 2018, 10:32:41 PM (7 years ago)

Author:

Yusuke Suzuki

Message:

Remove std::random_shuffle
​https://bugs.webkit.org/show_bug.cgi?id=185292

Reviewed by Darin Adler.

std::random_shuffle is deprecated in C++14 and removed in C++17,
since std::random_shuffle relies on rand and srand.
Use std::shuffle instead.

• jit/BinarySwitch.cpp:

(JSC::RandomNumberGenerator::RandomNumberGenerator):
(JSC::RandomNumberGenerator::operator()):
(JSC::RandomNumberGenerator::min):
(JSC::RandomNumberGenerator::max):
(JSC::BinarySwitch::build):

File:

• trunk/Source/JavaScriptCore/jit/BinarySwitch.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/jit/BinarySwitch.cpp

@@ -138 +138 @@
 }
 
+class RandomNumberGenerator {
+public:
+    using result_type = uint32_t;
+
+    RandomNumberGenerator(WeakRandom& weakRandom)
+        : m_weakRandom(weakRandom)
+    {
+    }
+
+    uint32_t operator()()
+    {
+        return m_weakRandom.getUint32();
+    }
+
+    static constexpr uint32_t min() { return std::numeric_limits<uint32_t>::min(); }
+    static constexpr uint32_t max() { return std::numeric_limits<uint32_t>::max(); }
+
+private:
+    WeakRandom& m_weakRandom;
+};
+
 void BinarySwitch::build(unsigned start, bool hardStart, unsigned end)
 {
@@ -196 +217 @@
             localCaseIndices.append(start + i);
         
-        std::random_shuffle(
+        std::shuffle(
             localCaseIndices.begin(), localCaseIndices.end(),
-            [this] (unsigned n) {
-                // We use modulo to get a random number in the range we want fully knowing that
-                // this introduces a tiny amount of bias, but we're fine with such tiny bias.
-                return m_weakRandom.getUint32() % n;
-            });
+            RandomNumberGenerator(m_weakRandom));
         
         for (unsigned i = 0; i < size - 1; ++i) {