Port r10939 to x64 and arm (inline Math.random in crankshaft).

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 3063 matching lines @@
   static const int kRandomSeedOffset =
       FixedArray::kHeaderSize + Context::RANDOM_SEED_INDEX * kPointerSize;
   __ mov(ebx, FieldOperand(eax, kRandomSeedOffset));
   // ebx: FixedArray of the global context's random seeds
 
   // Load state[0].
   __ mov(ecx, FieldOperand(ebx, ByteArray::kHeaderSize));
   // If state[0] == 0, call runtime to initialize seeds.
   __ test(ecx, ecx);
   __ j(zero, deferred->entry());
+  // Load state[1].
+  __ mov(eax, FieldOperand(ebx, ByteArray::kHeaderSize + kSeedSize));
+  // ecx: state[0]
+  // eax: state[1]
 
   // state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
   __ movzx_w(edx, ecx);
   __ imul(edx, edx, 18273);
   __ shr(ecx, 16);
   __ add(ecx, edx);
+  // Save state[0].
   __ mov(FieldOperand(ebx, ByteArray::kHeaderSize), ecx);
 
-  // Load state[1].
-  // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16);
-  __ mov(eax, FieldOperand(ebx, ByteArray::kHeaderSize + kSeedSize));
+  // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
   __ movzx_w(edx, eax);
   __ imul(edx, edx, 36969);
   __ shr(eax, 16);
   __ add(eax, edx);
+  // Save state[1].
   __ mov(FieldOperand(ebx, ByteArray::kHeaderSize + kSeedSize), eax);
 
-  // ecx: state[0]
-  // eax: state[1]
   // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
   __ shl(ecx, 14);
   __ and_(eax, Immediate(0x3FFFF));
   __ add(eax, ecx);
 
   __ bind(deferred->exit());
   // 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.
@@ skipping 1842 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32