Abstract: A method for arithmetic expression optimization comprises validating at least one input stack associated with a first instruction operable on at least one operand of a first type and optimizing the first instruction to a second instruction operable on at least one operand of a second type that is smaller than the first type based at least in part on the relative size of the first type and the second type. The method also comprises matching the second type with an operand type of at least one operand in the at least one input stack associated with the second instruction. The matching comprises changing the type of instructions in a chain of instructions to equal the second type if the operand type is less than the second type. The chain is bounded by the second instruction and a third instruction that is the source of the at least one operand.

Abstract: A method for arithmetic expression optimization includes receiving an operator and at least one operand of a first instruction defined for a first processor having a first base. The method also includes converting the first instruction to a second instruction optimized for a second processor having a second base smaller than the first base when the at least one operand does not carry potential overflow beyond the second base or when the operator is insensitive to overflow. The method also includes converting instructions in an instruction chain to a wider base larger than the second base and smaller or equal to the first base when the at least one operand carries potential overflow beyond the second base and when the operator is sensitive to overflow. The chain is bounded by the second instruction and a third instruction that has been previously optimized and is the source of the potential overflow.

Abstract: A method for arithmetic expression optimization includes receiving an operator and at least one operand of a first instruction defined for a first processor having a first base. The method also includes converting the first instruction to a second instruction optimized for a second processor having a second base smaller than the first base when overflow is impossible based at least in part on the operator and the relationship between the operand type and the second base. The method also includes converting instructions in an instruction chain to a wider base larger than the second base and smaller or equal to the first base when the at least one operand carries potential overflow beyond the second base and when the operator is sensitive to overflow. The chain is bounded by the second instruction and a third instruction that has been previously optimized and is the source of the potential overflow.

Abstract: A method for arithmetic overflow detection includes receiving a first instruction defined for a first processor having a first base, where the instruction comprises an operator and at least one operand having an operand type. The method also includes indicating whether the at least one operand has potential overflow based at least in part on the operator and the relationship between the operand type and a result type associated with the operator.

Abstract: A method for remote incremental program verification includes receiving content verified by at least one content provider, installing the content on a resource-constrained device and issuing the resource-constrained device to an end user. The content includes at least one program unit and each program unit includes an Application Programming Interface (API) definition file and an implementation. Each API definition file defines items in its associated program unit that are made accessible to one or more other program units and each implementation includes executable code corresponding to the API definition file. The executable code includes type specific instructions and data. According to one aspect, subsequent installation of content on the resource-constrained device is disabled. A resource-constrained device includes a memory for providing content verified by at least one content provider and a virtual machine that is capable of executing instructions included within the content.

Abstract: Apparatus and processes, including computer implemented processes, for managing exceptions throwable during execution of methods in one or more classes by a machine. Each method includes an exception handler array defining exception handlers associated with the method. The method includes combining the exception handler arrays for all methods into a single exception handler table.

Abstract: A system links architecture neutral code downloaded to a resource constrained computer. The code may be separated into one or more packages having one or more referenceable items. The system maps the one or more referenceable items into corresponding one or more tokens; orders the tokens to correspond to a run-time mode; downloads the packages to the resource constrained computer; and links the packages into an executable code using the ordered tokens.

Abstract: A method for arithmetic expression optimization comprises validating at least one input stack associated with a first instruction operable on at least one operand of a first type and optimizing the first instruction to a second instruction operable on at least one operand of a second type that is smaller than the first type based at least in part on the relative size of the first type and the second type. The method also comprises matching the second type with an operand type of at least one operand in the at least one input stack associated with the second instruction. The matching comprises changing the type of instructions in a chain of instructions to equal the second type if the operand type is less than the second type. The chain is bounded by the second instruction and a third instruction that is the source of the at least one operand.

Abstract: A method for arithmetic expression optimization includes receiving an operator and at least one operand of a first instruction defined for a first processor having a first base. The method also includes converting the first instruction to a second instruction optimized for a second processor having a second base smaller than the first base when overflow is impossible based at least in part on the operator and the relationship between the operand type and the second base. The method also includes converting instructions in an instruction chain to a wider base larger than the second base and smaller or equal to the first base when the at least one operand carries potential overflow beyond the second base and when the operator is sensitive to overflow. The chain is bounded by the second instruction and a third instruction that has been previously optimized and is the source of the potential overflow.

Abstract: A method for arithmetic expression optimization includes receiving an operator and at least one operand of a first instruction defined for a first processor having a first base. The method also includes converting the first instruction to a second instruction optimized for a second processor having a second base smaller than the first base when the at least one operand does not carry potential overflow beyond the second base or when the operator is insensitive to overflow. The method also includes converting instructions in an instruction chain to a wider base larger than the second base and smaller or equal to the first base when the at least one operand carries potential overflow beyond the second base and when the operator is sensitive to overflow. The chain is bounded by the second instruction and a third instruction that has been previously optimized and is the source of the potential overflow.

Abstract: A method for arithmetic overflow detection includes receiving a first instruction defined for a first processor having a first base, where the instruction comprises an operator and at least one operand having an operand type. The method also includes indicating whether the at least one operand has potential overflow based at least in part on the operator and the relationship between the operand type and a result type associated with the operator.