Sun Microsystems, Inc.

Oracle America, Inc.

Zhiqun Chen

Judith E Schwabe

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.

Optimization of N-base typed arithmetic instructions via rework

A method for arithmetic expression optimization includes receiving a first instruction defined for a first processor having a first base, the first instruction including an operator and at least one operand, converting the first instruction to a second instruction optimized for a second processor having a second base when all operands do not carry potential overflow or when the operator is insensitive to overflow, the second base being smaller than the first base, and converting to a wider base a third instruction that is the source of the overflow when the at least one operand the potential for overflow and when the operator is sensitive to overflow. An apparatus for arithmetic expression optimization includes at least one memory having program instructions and at least one processor configured to use the program instructions to receive a first instruction defined for a first processor having a first base, convert the first instruction to a second instruction optimized for a second processor having a second base when every one of the at least one operand does not carry potential overflow or when the operator is insensitive to overflow, the second base being smaller than the first base, and convert to a wider base a third instruction that is the source of the overflow when the at least one operand the potential for overflow and when the operator is sensitive to overflow.

Optimization of n-base typed arithmetic expressions

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.

Overflow predictive arithmetic instruction optimization using chaining

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.

Predictive arithmetic overflow detection

Language subset validation includes validating multiple program modules that comprise a program. The program modules include multiple bytecodes defined for a first computer language that is a hardware-dependent subset of a second computer language. The validation includes indicating an error condition for items in the multiple program modules that are not defined for the first computer language, indicating an error condition for items in the multiple program modules that are not supported by an execution environment of the first computer language and indicating an error condition for items in the multiple program modules that are defined for the first computer language but used in a manner inconsistent with the first computer language.

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Palo Alto, CA, United States of America

Zhiqun Chen