Method and apparatus for selecting ways to compile at runtime

A method of generating different sets of native instructions for executing a floating point operation creating a floating point underflow in a software program, the method comprising:

• compiling the floating point operation in a first way to create a first set of native instructions;
• determining whether the floating point operation can create a floating point underflow;
• determining at runtime of the software program that it would be desirable to compile the floating point operation in a different way based on a predetermined criteria;
• and
• recompiling the floating point operation in the different way to create a second set of native instructions whereby the second set of native instructions replaces the first set of native instructions.

A method of executing a floating point operation in a program, the method comprising:

• determining whether a floating point operation can create a floating point underflow;
• checking a particular indicator to determine how many times a specific floating point operation has caused an underflow;
• and
• compiling the specific floating point operation using a first way when the particular indicator meets predetermined criteria and otherwise compiling the specific floating point operation using a second way.

A method of generating instructions for detecting floating point underflow, the method comprising:

• determining whether an operation in a program can create a floating point underflow;
• examining an underflow indicator to measure a tendency of a particular floating point operation for causing an underflow;
• compiling the particular floating point operation using a trap routine according to the tendency of the particular floating point operation for causing an underflow;
• and
• recompiling the floating point operation using an inline explicit check according to the tendency of the particular floating point operation for causing an underflow.

A computer program product for determining at runtime how to compile bytecode instructions associated with a floating point operation creating a floating point underflow in a computer program, comprising:

• a computer code that retrieves a bytecode instruction associated with the floating point operation that can be compiled in a plurality of ways;
• a computer code that determines whether the floating point operation can create a floating point underflow;
• a computer code that compiles the bytecode instruction a first way;
• a computer code that determines at runtime that a second way of compiling the bytecode instruction is desirable based on a predetermined criteria;
• and
• a computer code that recompiles the bytecode instruction the second way;
• and
• a computer readable medium that stores the computer codes.

A computer program product for executing a floating point operation in a program, comprising:

• a computer code that determines whether a floating point operation can create a floating point underflow;
• a computer code that checks a particular indicator to determine how many times a particular floating point operation has caused an underflow;
• a computer code that compiles the particular floating point operation using a first way when the particular indicator meets predetermined criteria and otherwise compiling the floating point operation using a second way;
• and
• a computer readable medium that stores the computer codes.

A system for determining at runtime how to compile bytecode instructions associated with a floating point operation causing a floating point underflow in a computer program, the system comprising:

• a bytecode retriever for retrieving a bytecode instruction associated with the floating point operation that can be compiled in a plurality of ways;
• a floating point underflow detector for detecting whether the floating point operation can create a floating point underflow;
• a compiling module for compiling the bytecode instruction in one of a first way and a second way;
• and
• an alternative compiling detector for determining at runtime that the second way of compiling the instruction is desirable based on a predetermined criteria.

A system for executing a floating point instruction in a program, the system comprising:

• an instruction evaluator for determining whether a floating point instruction can create a floating point underflow;
• a floating point underflow indicator for keeping a count of the number of times a particular floating point operation has caused a floating point underflow;
• and
• a compiler for compiling the particular floating point operation using a first way when the particular indicator meets predetermined criteria and otherwise compiling the particular floating point operation using a second way, wherein the floating point underflow indicator is checked to determine how many times the particular floating point operation has caused an underflow.

A system for determining at runtime how to compile bytecode instructions associated with a floating point operation creating a floating point underflow in a computer program having instructions comprising:

• one or more processors;
• and
• a computer readable medium storing a program for execution by the one or more processors comprising:
• computer code that retrieves an instruction in the floating point operation that can be compiled in a plurality of ways;
• computer code that determines whether the floating point operation can create a floating point underflow;
• computer code that compiles the instruction in a first way;
• computer code that determines at runtime that a second way of compiling the instruction is desirable based on a predetermined criteria;
• and
• computer code that recompiles the instruction in the second way.