Problem The problem to be solved is to seek an alternative to known addressing methods which provides the same or similar effects or is more secure. Solution The problem is solved by a method (40) of addressing memory in a data-processing apparatus (10) comprising, when a central processing unit (11), while performing a task (31, 32, 33, 34) of the apparatus (10), executes an instruction involving a pointer (57) into a segment (s, r, d, h, f, o, i, c) of the memory: decoding the instruction by means of an instruction decoder (12), generating an address (45) within the memory by means of a safe pointer operator (41) operating on the pointer (57), augmenting the address (45) by an identifier (43) of the task (31, 32, 33, 34) and an identifier (44) of the segment (s, r, d, h, f, o, i, c), said identifiers (43, 44) being hardware-controlled (42), and, based on the augmented address (45), dereferencing the pointer (57) via a memory management unit (13).

Addressability of instructions and the addressing of data ranges are extended. One or more operands obtained from fields explicitly specified by an instruction are overridden (i.e., ignored), and instead, an address based on the instruction (e.g., an instruction address) is substituted for the one or more operands. This provides an address having more bits than allowed by the operand being overridden, thereby extending addressability of the instruction and extended data range addressing. Further, in one aspect, additional bits may be added to one or more immediate fields of the instruction, thereby extending addressability of the instructions and extending data range addressing.

Addressability of instructions and the addressing of data ranges are extended. One or more operands obtained from fields explicitly specified by an instruction are overridden (i.e., ignored), and instead, an address based on the instruction (e.g., an instruction address) is substituted for the one or more operands. This provides an address having more bits than allowed by the operand being overridden, thereby extending addressability of the instruction and extended data range addressing. Further, in one aspect, additional bits may be added to one or more immediate fields of the instruction, thereby extending addressability of the instructions and extending data range addressing.

A method, an apparatus, and an electronic device for controlling memory access are disclosed. According to an embodiment, there is provided a method for controlling access to a memory including a plurality of memory modules configured in parallel. The method comprises: receiving an access instruction including an addressing field which comprise a parallel control field for controlling parallel access, a module address field for indicating a memory module, and an in-module address field for indicating an addresses within a memory module; parsing the access instructions to determine the parallel control field, the module address field and the in-module address field; determining one or more memory modules to be accessed based on the parallel control field and the module address field; and accessing one or more addresses which are within the one or more memory modules to be accessed and assigned by the in-module address field.

In an aspect, a processor supports modeless execution of 64 bit and 32 bit instructions. A Load/Store Unit (LSU) decodes an instruction that without explicit opcode data indicating whether the instruction is to operate in a 32 or 64 bit memory address space. LSU treats the instruction either as a 32 or 64 bit instruction in dependence on values in an upper 32 bits of one or more 64 bit operands supplied to create an effective address in memory. In an example, a 4 GB space addressed by 32-bit memory space is divided between upper and lower portions of a 64-bit address space, such that a 32-bit instruction is differentiated from a 64-bit instruction in dependence on whether an upper 32 bits of one or more operands is either all binary 1 or all binary 0. Such a processor may support decoding of different arithmetic instructions for 32-bit and 64-bit operations.

A processor architecture includes a register file hierarchy to implement virtual registers that provide a larger set of registers than those directly supported by an instruction set architecture to facilitate multiple copies of the same architecture register for different processing threads, where the register file hierarchy includes a plurality of hierarchy levels. The processor architecture further includes a plurality of execution units coupled to the register file hierarchy.

An apparatus and method are provided for comparing regions associated with first and second bounded pointers to determine whether the region defined for the second bounded pointer is a subset of the region defined for the first bounded pointer. Each bounded pointer has a pointer value and associated upper and lower limits identifying the memory region for that bounded pointer. The apparatus stores first and second bounded pointer representations, each representation comprising a pointer value having p bits, and identifying the upper and lower limits in a compressed form by identifying a lower limit mantissa of q bits, an upper limit mantissa of q bits and an exponent value e. A most significant pqe bits of the lower limit and the upper limit is derivable from the most significant pqe bits of the pointer value. Mapping circuitry is used to map the lower limit mantissas and upper limit mantissas of the first and second bounded pointer representations to a q+x bit address space comprising 2.sup.x regions of size 2.sup.n1, where n1 is the value of n determined when using the exponent value of the first bounded pointer representation. Mantissa extension circuitry extends the lower limit and upper limit mantissas for each bounded pointer representation to create extended lower limit and upper limit mantissas comprising q+x bits, where a most significant x bits of each extended limit mantissa are mapping bits identifying which region the associated limit mantissa is mapped to. The determination circuitry then determines whether the region for the second pointer is a subset of the region for the first bounded pointer by comparing the extended lower and upper limit mantissas.

A microcontroller includes a program memory, data memory, central processing unit, at least one register module, a memory management unit, and a transport network. Instructions are executed in one clock cycle via an instruction word. The instruction word indicates the source module from which data is to be retrieved and the destination module to which data is to be stored. The address/data capability of an instruction word may be extended via a prefix module. If an operation is performed on the data, the source module or the destination module may perform the operation during the same clock cycle in which the data is transferred.

A register protection mechanism for a virtualized accelerated processing device (APD) is disclosed. The mechanism protects registers of the accelerated processing device designated as physical-function-or-virtual-function registers (PF-or-VF* registers), which are single architectural instance registers that are shared among different functions that share the APD in a virtualization scheme whereby each function can maintain a different value in these registers. The protection mechanism for these registers comprises comparing the function associated with the memory address specified by a particular register access request to the currently active function for the APD and disallowing the register access request if a match does not occur.

Disclosed are systems and methods of implementing per-thread granular memory access permissions. An example method may include: initializing a plurality of memory protection keys associated with a plurality of page table entries associated with an address space of a processing thread; loading, to a protection key rights register associated with the processing thread, a plurality of memory access permissions referenced by the memory protection keys; initializing a system call filter to prevent the processing thread from modifying the protection key rights register; and causing the processing thread to be executed.