Support inlining and crankshaft optimization of Math.random.

src/ia32/lithium-codegen-ia32.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 2998 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));
+  ASSERT(ToRegister(instr->InputAt(0)).is(eax));
+
+  __ PrepareCallCFunction(1, ebx);
+  __ mov(eax, FieldOperand(eax, GlobalObject::kGlobalContextOffset));
+  __ mov(Operand(esp, 0), eax);
+  __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
+
+  // Convert 32 random bits in eax to 0.(32 random bits) in a double
+  // by computing:
+  // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
+  __ mov(ebx, Immediate(0x49800000));  // 1.0 x 2^20 as single.
+  __ movd(xmm2, ebx);
+  __ movd(xmm1, eax);
+  __ cvtss2sd(xmm2, xmm2);
+  __ xorps(xmm1, xmm2);
+  __ subsd(xmm1, xmm2);
+}
+
+
 void LCodeGen::DoMathLog(LUnaryMathOperation* instr) {
   ASSERT(instr->value()->Equals(instr->result()));
   XMMRegister input_reg = ToDoubleRegister(instr->value());
   Label positive, done, zero;
   __ xorps(xmm0, xmm0);
   __ ucomisd(input_reg, xmm0);
   __ j(above, &positive, Label::kNear);
   __ j(equal, &zero, Label::kNear);
   ExternalReference nan =
       ExternalReference::address_of_canonical_non_hole_nan();
@@ skipping 1592 matching lines @@
       this, pointers, Safepoint::kLazyDeopt);
   __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION, safepoint_generator);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32