RFC: Switch to ast ids (instead of positions) for type feedback.

src/v8globals.h

 // 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 86 matching lines @@
 const int kProcessorCacheLineSize = 64;
 
 // Constants relevant to double precision floating point numbers.
 
 // Quiet NaNs have bits 51 to 62 set, possibly the sign bit, and no
 // other bits set.
 const uint64_t kQuietNaNMask = static_cast<uint64_t>(0xfff) << 51;
 // If looking only at the top 32 bits, the QNaN mask is bits 19 to 30.
 const uint32_t kQuietNaNHighBitsMask = 0xfff << (51 - 32);
 
+// AST node ids.
+typedef unsigned AstId;

[fschneider, 2011/02/11 11:28:18]

Maybe consider leaving ast id as integers (like before) - although I like having
a separate type AstId, I'm not sure if the typedef alone gives us much benefit
overall.

It would also affect less source lines if we leave the type for ast ids
unchanged (i.e. making it easier to merge).

+const AstId kNoAstId = static_cast<AstId>(-1);
+
 
 // -----------------------------------------------------------------------------
 // Forward declarations for frequently used classes
 // (sorted alphabetically)
 
 class AccessorInfo;
 class Allocation;
 class Arguments;
 class Assembler;
 class AssertNoAllocation;
@@ skipping 347 matching lines @@
                   CMOV = 15,   // x86
                   RDTSC = 4,   // x86
                   CPUID = 10,  // x86
                   VFP3 = 1,    // ARM
                   ARMv7 = 2,   // ARM
                   SAHF = 0};   // x86
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8GLOBALS_H_