Computer Processor Providing Exception Handling with Reduced State Storage

A computer architecture allows for simplified exception handling by restarting the program after exceptions at the beginning of idempotent regions, the idempotent regions allowing re-execution without the need for restoring complex state information from checkpoints. Recovery from mis-speculation may be provided by a similar mechanism but using smaller idempotent regions reflecting a more frequent occurrence of mis-speculation. A compiler generating different idempotent regions for speculation and exception handling is also disclosed.