Support inlining and crankshaft optimization of Math.random.

src/x64/lithium-codegen-x64.cc

 // Copyright 2012 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
@@ skipping 2913 matching lines @@
     MathPowStub stub(MathPowStub::INTEGER);
     __ CallStub(&stub);
   } else {
     ASSERT(exponent_type.IsDouble());
     MathPowStub stub(MathPowStub::DOUBLE);
     __ CallStub(&stub);
   }
 }
 
 
+void LCodeGen::DoRandom(LRandom* instr) {
+  // Having marked this instruction as a call we can use any
+  // registers.
+  ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
+
+  // Choose the right register for the first argument depending on
+  // calling convention.
+#ifdef _WIN64
+  ASSERT(ToRegister(instr->InputAt(0)).is(rcx));
+  Register global_object = rcx;
+#else
+  ASSERT(ToRegister(instr->InputAt(0)).is(rdi));
+  Register global_object = rdi;
+#endif
+
+  __ PrepareCallCFunction(1);
+  __ movq(global_object,
+          FieldOperand(global_object, GlobalObject::kGlobalContextOffset));
+  __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
+
+  // Convert 32 random bits in rax to 0.(32 random bits) in a double
+  // by computing:
+  // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
+  __ movl(rcx, Immediate(0x49800000));  // 1.0 x 2^20 as single.
+  __ movd(xmm2, rcx);
+  __ movd(xmm1, rax);
+  __ cvtss2sd(xmm2, xmm2);
+  __ xorps(xmm1, xmm2);
+  __ subsd(xmm1, xmm2);
+}
+
+
 void LCodeGen::DoMathLog(LUnaryMathOperation* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
   TranscendentalCacheStub stub(TranscendentalCache::LOG,
                                TranscendentalCacheStub::UNTAGGED);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
 }
 
 
 void LCodeGen::DoMathTan(LUnaryMathOperation* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
@@ skipping 1398 matching lines @@
   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64