[turbofan] Add support for ARM64 Ubfx

src/base/utils/random-number-generator.cc

Index: src/base/utils/random-number-generator.cc
diff --git a/src/base/utils/random-number-generator.cc b/src/base/utils/random-number-generator.cc
index a1ec9d71842766d4cb0f51962e05c4c7aae00f32..263f37281dc52871eabb9e8f40f0ff8e2dea86bc 100644
--- a/src/base/utils/random-number-generator.cc
+++ b/src/base/utils/random-number-generator.cc
@@ -102,6 +102,13 @@ double RandomNumberGenerator::NextDouble() {
 }
 
 
+int64_t RandomNumberGenerator::NextInt64() {
+  int64_t lo = static_cast<int64_t>(Next(32));
+  int64_t hi = static_cast<int64_t>(Next(32));
+  return (lo & 0xffffffff) | (hi << 32);
+}

[Benedikt Meurer, 2014/10/08 11:40:12]

This is undefined behaviour in C++. Should be:

uint64_t lo = bit_cast<unsigned>(Next(32));
uint64_t hi = bit_cast<unsigned>(Next(32));
return lo | (hi << 32);

[m.m.capewell, 2014/10/08 17:35:02]

Done.

+
+
 void RandomNumberGenerator::NextBytes(void* buffer, size_t buflen) {
   for (size_t n = 0; n < buflen; ++n) {
     static_cast<uint8_t*>(buffer)[n] = static_cast<uint8_t>(Next(8));