Change hash computation for transcendental cache to use arithmetic...

src/x64/codegen-x64.cc

 // Copyright 2010 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 8159 matching lines @@
   __ j(not_equal, &runtime_call);
   // Input is a HeapNumber. Push it on the FPU stack and load its
   // bits into rbx.
   __ fld_d(FieldOperand(rax, HeapNumber::kValueOffset));
   __ movq(rbx, FieldOperand(rax, HeapNumber::kValueOffset));
   __ movq(rdx, rbx);
   __ bind(&loaded);
   // ST[0] == double value
   // rbx = bits of double value.
   // rdx = also bits of double value.
-  // Compute hash (h is 32 bits, bits are 64):
+  // Compute hash (h is 32 bits, bits are 64 and the shifts are arithmetic):
   //   h = h0 = bits ^ (bits >> 32);
   //   h ^= h >> 16;
   //   h ^= h >> 8;
   //   h = h & (cacheSize - 1);
   // or h = (h0 ^ (h0 >> 8) ^ (h0 >> 16) ^ (h0 >> 24)) & (cacheSize - 1)
   __ sar(rdx, Immediate(32));
   __ xorl(rdx, rbx);
   __ movl(rcx, rdx);
   __ movl(rax, rdx);
   __ movl(rdi, rdx);
-  __ shrl(rdx, Immediate(8));
-  __ shrl(rcx, Immediate(16));
-  __ shrl(rax, Immediate(24));
+  __ sarl(rdx, Immediate(8));
+  __ sarl(rcx, Immediate(16));
+  __ sarl(rax, Immediate(24));
   __ xorl(rcx, rdx);
   __ xorl(rax, rdi);
   __ xorl(rcx, rax);
   ASSERT(IsPowerOf2(TranscendentalCache::kCacheSize));
   __ andl(rcx, Immediate(TranscendentalCache::kCacheSize - 1));
 
   // ST[0] == double value.
   // rbx = bits of double value.
   // rcx = TranscendentalCache::hash(double value).
   __ movq(rax, ExternalReference::transcendental_cache_array_address());
@@ skipping 3740 matching lines @@
 }
 
 #endif
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64