Method and system for fast unlinking of a linked branch in a caching dynamic translator

A method for linking and unlinking code fragments stored in a code cache, comprising the steps of:

• associating a memory area with a branch in a first code fragment that branches outside the cache;
• determining that the branch can be set to branch to a location in a second code fragment stored in the cache;
• updating the branch to branch to the determined location in the second code fragment, thereby linking the first code fragment to the second code fragment;
• and
• adding branch reconstruction information to the associated memory area corresponding to the branch in its state before being updated to link the first and second code fragments.

A code cache controller for linking and unlinking a first code fragment and a second code fragment stored in a cache, comprising:

• a first component for associating a memory area with a branch in a first code fragment that branches outside of the cache;
• a second component for storing at least one instruction in the memory area that is executed when the branch is taken and control is to transfer to code outside of the cache;
• a third component for determining that the branch can be set to branch to a location in a second code fragment stored in the cache;
• a fourth component for changing the branch so that it branches to the second code fragment stored in the code cache, thereby linking the first and second code fragments;
• and
• a fifth component for adding information to the associated memory area corresponding to the branch in its state before being changed to link the first and second code fragments.

A code cache controller for linking and unlinking code fragments stored in a code cache, comprising:

• a first component for associating a memory area with a branch in a first code fragment that branches outside the cache;
• a second component for determining that the branch can be set to branch to a location in a second code fragment stored in the cache;
• a third component for updating the branch to branch to the determined location in the second code fragment, thereby linking the first code fragment to the second code fragment;
• and
• a fourth component for adding branch reconstruction information to the associated memory area corresponding to the branch in its state before being updated to link the first and second code fragments.

A computer-readable medium configured to control the operation of a computer to linking and unlink a first code fragment and a second code fragment stored in a cache, the computer-readable medium configured to:

• associate a memory area with a branch in a first code fragment that branches outside of the cache;
• store at least one instruction in the memory area that is executed when the branch is taken and control is to transfer to code outside of the cache;
• determine that the branch can be set to branch to a location in a second code fragment stored in the cache;
• change the branch so that it branches to the second code fragment stored in the code cache, thereby linking the first and second code fragments;
• and
• add information to the associated memory area corresponding to the branch in its state before being changed to link the first and second code fragments.

A computer-readable medium configured to control the operation of a computer to linking and unlink a first code fragment and a second code fragment stored in a cache, the computer-readable medium configure to:

• associate a memory area with a branch in a first code fragment that branches outside the cache;
• determine that the branch can be set to branch to a location in a second code fragment stored in the cache;
• update the branch to branch to the determined location in the second code fragment, thereby linking the first code fragment to the second code fragment;
• and
• add branch reconstruction information to the associated memory area corresponding to the branch in its state before being updated to link the first and second code fragments.