Apparatus and method for controlling debugging of program instructions including a transaction

A method of operating an apparatus comprising:

• employing processing circuitry to execute program instructions including a transaction comprising a number of program instructions that execute to generate updates to state data and to commit said updates if said transaction completes without a conflict;
• storing stepping control data used to control operation of the processing circuitry;
• responsive to the stepping control data having a first value, operating the processing circuitry in a single stepping mode, where the processing circuitry initiates a debug event following execution of each instruction;
• and
• responsive to the stepping control data having a second value, operating the processing circuitry in a step over transaction mode, where the processing circuitry is arranged, when executing the number of program instructions within the transaction, to suppress initiation of the debug event until the transaction has completed.

A debug control method, comprising:

• employing processing circuitry to execute program instructions including a transaction comprising a number of program instructions that execute to generate updates to state data and to commit said updates if said transaction completes without a conflict;
• causing said processing circuitry to execute an instruction from said program instructions, to store syndrome information in a data storage location at least if the instruction is a first instruction of the transaction, and to initiate a debug event;
• responsive to said debug event, performing within a debugger the following steps:
• determining from said syndrome information whether said instruction is the first instruction of said transaction;
• and
• on determining that said instruction is the first instruction of said transaction, analysing the transaction to determine at least one exit point from said transaction, issuing breakpoint information for said at least one exit point as control data for said processing circuitry, and triggering the processing circuitry to resume execution of said program instructions starting with said first instruction of said transaction.

An apparatus to be analysed by a debugger, comprising:

• processing circuitry to execute program instructions including a transaction comprising a number of program instructions that execute to generate updates to state data and to commit said updates if said transaction completes without a conflict;
• and
• control storage to store control data used to control operation of the processing circuitry;
• the processing circuitry being responsive to the control data identifying a single stepping mode, to execute an instruction from said program instructions, to store syndrome information in a data storage location at least if the instruction is a first instruction of the transaction, and to initiate a debug event.