Property Accesses in Dynamically Typed Programming Languages

A computer-readable storage medium configured with data and with instructions that when executed by at least one processor causes the processor to perform an algorithmic process for generation of machine code for a sequence of property accesses in a dynamically typed programming language using equivalent object type specialization, the process comprising the steps of:

• (a) when types in a polymorphic inline cache of an object are not equivalent, then emitting a nondirect property access code, namely, a code which includes instructions to use a polymorphic inline cache for at least one property access which does not begin the sequence of property accesses;
• (b) when types in the object's polymorphic inline cache are equivalent, but no type set is available from a compiler value table to compare with a cached type set computed from the object's polymorphic inline cache, then creating an equivalent type cache and emitting a type check code for the property access that begins the sequence of property accesses;
• (c) when types in the object's polymorphic inline cache are equivalent, and a type set is retrieved from a compiler value table, but a polymorphic inline cached type set of the object does not match the type set retrieved from the compiler value table, then emitting a nondirect property access code;
• and
• (d) when types in the object's polymorphic inline cache are equivalent, and the polymorphic inline cached type set of the object matches the type set retrieved from the compiler value table, then emitting a direct property access code which upon execution directly accesses a property value at a hard-coded offset in a memory region of the object.

An algorithmic process for execution of a sequence of property accesses in a dynamically typed programming language using equivalent object type specialization, the process comprising:

• (a) running code which does a type check by comparing an object type to a designated guard type of an equivalent type cache;
• (b) when the object type equals the designated guard type, then without running further type check code executing code which accesses a property's value at a hard-coded offset into an object's memory;
• (c) when the object type does not equal the designated guard type, running type check comparison code which compares the object type to at least one secondary entry of the equivalent type cache;
• (d) when the type check comparison code determines that the object type matches any entry in the equivalent type cache, then without running further type check code executing code for the sequence of property accesses, each property access either loading a property value or storing a property value, each property access accessing a location at a hard-coded offset into an object's memory;
• and
• (e) when the type check comparison code determines that the object type does not match any entry in the equivalent type cache, then executing code which determines whether the object type is equivalent to the types in the equivalent type cache with respect to the properties accessed, by using a property equivalence record which is associated with the equivalent type cache.