Oracle America, Inc.

Oracle International Corporation

Sheldon M Lobo

Fu-Hwa Wang

Raj Prakash

In general, in one aspect, the invention relates to a method for managing virtual memory (VM). The method includes receiving, from an application, a first access request comprising a first VM address identifying a VM location, obtaining a current VM location version value for the VM location, obtaining a first submitted VM location version value from the first VM address, and in response to a determination that the current VM location version value and the first submitted VM location version value match: servicing the first access request using the first VM address.

Stale pointer detection with overlapping versioned memory

Redundant run-time type information is removed from a compiled program. The redundant type information may be unneeded and/or duplicate. Unneeded type information is removed by selecting instances of type information from read only data sections of object files. The entire compiled program is searched for instructions that use the instances. The instances that do not correspond to such instructions are removed from the object files. Duplicate type information is removed by selecting instances of type information from read only data sections of object files. The read only data sections of the other object files in the compiled program are then searched for the selected instances. The selected instances that exist in the read only data sections of the other object files are removed. Redundant type information may be removed from individual object files before concatenation into a single binary file and/or from a single binary file after concatenation.

Redundant run-time type information removal

Duplicative code found in modules of high level computer code can be eliminated at link-time. A compiler forms a plurality of object files from a software program in which each object file includes one or more functions associated with the software program. An analyzer examines each function to ascertain whether any of the plurality of object files include functional duplicates. In addition, call and caller routing references are determined for each of the object files and functions contained therein. Responsive to determining that a functional equivalence exists, the routing of duplicative functions is altered to reference a golden copy of the same function. Once the call and caller information has been re-routed, the duplicative function(s) is(are) deleted.

Link-time redundant code elimination using functional equivalence

A system performs operations comprising creating a call graph for a program translated from source code, identifying redundant exception handling code in the program utilizing the call graph, and removing the redundant exception handling code. The operation of identifying redundant exception handling code may comprise identifying at least one function or callsite by determining that a first function in the at least one function's or callsite's callee chain throws an exception and that the exception is handled by a second function in the function's or callsite's callee chain or by determining that an exception is not thrown in the at least one function's or callsite's callee chain. The operation of removing the redundant exception handling code may comprise removing redundant exception handling code included in at least one function or callsite and/or removing at least one entry for the at least one function or callsite from an exception lookup table.

Redundant exception handling code removal

An application compiled to a binary executable according to a first set of binary interface rules has selected caller/callee pairs that present parameter passing improvement possibilities modified from compliance with the first set of binary interface rules to compliance with a second set of binary interface rules to improve the efficiency of parameter passing, such as by reducing the number of instructions used to pass the parameters. A binary executable search engine searches the binary executable to locate functions having parameter passing improvement possibilities. Identified caller/callee function pairs are updated with a function modifier to pass the parameters more efficiently. Selected of the identified callee functions are cloned so that a cloned function is modified instead of the original function, thus leaving the original function to pass parameters with functions beyond the view of the binary executable search engine.

System and method for binary translation to improve parameter passing

Techniques for reordering the data section of a computer program are provided for improving the run-time performance of the program. A computer program that comprises a data section and a code section is compiled. After the computer program has been compiled, the data section of the computer program is reordered based at least on annotation information that is included in a plurality of object files that represent the object code of the program. A specific binary file that is a specific executable version of the computer program is generated. The specific binary file includes the data section of the computer program that has been reordered. The data section of the computer program may be reordered during the linking of the plurality of the object files. Alternatively, the data section may be reordered after the computer program has been linked into a first binary file by rewriting the first binary file into the specific binary file.

Data reordering for improved cache operation

A system and method for optimizing compiler performance including outlining cold code at link time, rather than compile time, such that trampolines are not required. Branch instructions connecting a hot block to a cold block can be converted from a short branch distance limit to a longer branch distance limit, further optimizing code performance. Editors, implementing a plurality of windows that can be maintained for each function, can display the maximum distance that code blocks can be safely outlined. Other implementations allow the optimal placement of code that is significantly greater in size than the maximum possible branch distance.

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Cary, NC, United States of America

Sheldon M Lobo