Support inlining and crankshaft optimization of Math.random.

src/arm/lithium-codegen-arm.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 3177 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(d7));
+  ASSERT(ToRegister(instr->InputAt(0)).is(r0));
+
+  __ PrepareCallCFunction(1, scratch0());
+  __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalContextOffset));
+  __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
+
+  // 0x41300000 is the top half of 1.0 x 2^20 as a double.
+  // Create this constant using mov/orr to avoid PC relative load.
+  __ mov(r1, Operand(0x41000000));
+  __ orr(r1, r1, Operand(0x300000));
+  // Move 0x41300000xxxxxxxx (x = random bits) to VFP.
+  __ vmov(d7, r0, r1);
+  // Move 0x4130000000000000 to VFP.
+  __ mov(r0, Operand(0, RelocInfo::NONE));
+  __ vmov(d8, r0, r1);
+  // Subtract and store the result in the heap number.
+  __ vsub(d7, d7, d8);
+}
+
+
 void LCodeGen::DoMathLog(LUnaryMathOperation* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(d2));
   TranscendentalCacheStub stub(TranscendentalCache::LOG,
                                TranscendentalCacheStub::UNTAGGED);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
 }
 
 
 void LCodeGen::DoMathTan(LUnaryMathOperation* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(d2));
@@ skipping 1542 matching lines @@
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 
 
 #undef __
 
 } }  // namespace v8::internal