v8/test/cctest/test-random.cc

// Copyright 2012 the V8 project authors. All rights reserved.
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#include "v8.h"

#include "cctest.h"
#include "compiler.h"
#include "execution.h"
#include "isolate.h"


using namespace v8::internal;

static v8::Persistent<v8::Context> env;


void SetSeeds(Handle<ByteArray> seeds, uint32_t state0, uint32_t state1) {
  for (int i = 0; i < 4; i++) {
    seeds->set(i, static_cast<byte>(state0 >> (i * kBitsPerByte)));
    seeds->set(i + 4, static_cast<byte>(state1 >> (i * kBitsPerByte)));
  }
}


void TestSeeds(Handle<JSFunction> fun,
               Handle<Context> context,
               uint32_t state0,
               uint32_t state1) {
  bool has_pending_exception;
  Handle<JSObject> global(context->global());
  Handle<ByteArray> seeds(context->random_seed());

  SetSeeds(seeds, state0, state1);
  Handle<Object> value =
      Execution::Call(fun, global, 0, NULL, &has_pending_exception);
  CHECK(value->IsHeapNumber());
  CHECK(fun->IsOptimized());
  double crankshaft_value = HeapNumber::cast(*value)->value();

  SetSeeds(seeds, state0, state1);
  V8::FillHeapNumberWithRandom(*value, *context);
  double runtime_value = HeapNumber::cast(*value)->value();
  CHECK_EQ(runtime_value, crankshaft_value);
}


TEST(CrankshaftRandom) {
  if (env.IsEmpty()) env = v8::Context::New();
  // Skip test if crankshaft is disabled.
  if (!V8::UseCrankshaft()) return;
  v8::HandleScope scope;
  env->Enter();

  Handle<Context> context(Isolate::Current()->context());
  Handle<JSObject> global(context->global());
  Handle<ByteArray> seeds(context->random_seed());
  bool has_pending_exception;

  CompileRun("function f() { return Math.random(); }");

  Object* symbol = FACTORY->LookupAsciiSymbol("f")->ToObjectChecked();
  MaybeObject* fun_object =
      context->global()->GetProperty(String::cast(symbol));
  Handle<JSFunction> fun(JSFunction::cast(fun_object->ToObjectChecked()));

  // Optimize function.
  Execution::Call(fun, global, 0, NULL, &has_pending_exception);
  Execution::Call(fun, global, 0, NULL, &has_pending_exception);
  if (!fun->IsOptimized()) fun->MarkForLazyRecompilation();

  // Test with some random values.
  TestSeeds(fun, context, 0xC0C0AFFE, 0x31415926);
  TestSeeds(fun, context, 0x01020304, 0xFFFFFFFF);
  TestSeeds(fun, context, 0x00000001, 0x00000000);

  // Test that we bail out to runtime when seeds are uninitialized (zeros).
  SetSeeds(seeds, 0, 0);
  Handle<Object> value =
      Execution::Call(fun, global, 0, NULL, &has_pending_exception);
  CHECK(value->IsHeapNumber());
  CHECK(fun->IsOptimized());
  double crankshaft_value = HeapNumber::cast(*value)->value();
  CHECK_NE(0.0, crankshaft_value);
}