Abstract: An instruction processor to execute two instruction sets. Instructions are stored in different virtual memory pages of a single address space, and are coded for computers of two different instruction sets, and use of two different calling conventions. The instruction processor interprets instructions under, alternately, the first or second instruction set as directed by a first flag stored in table entries corresponding to memory pages for the instructions. The processor recognizes when program execution has transferred from a page of instructions using the first data storage convention to a page of instructions using the second data storage convention, as indicated by a second flag stored in the table entries, and then adjusts a data storage content of the computer from the first storage convention to the second data storage convention. A history record provides a record of a classification of a recently-executed instruction.

Abstract: A computer. An instruction pipeline and memory access unit execute instructions in a logical address space of a memory of the computer. An address translation circuit translates address references generated by the program from the program's logical address space to the computer's physical address space. Profile circuitry is cooperatively interconnected with the instruction pipeline and configured to detect, without compiler assistance for execution profiling, occurrence of profilable events occurring in the instruction pipeline, and is cooperatively interconnected with the memory access unit to record profile information describing physical memory addresses referenced during an execution interval of the program.

Abstract: A method and computer for performance of the method. While executing a program on a computer, the computer uses registers of a general register file for storage of instruction results. Profile information describing the profileable events is recorded into the general register file as the profileable events occur, without first capturing the information into a main memory of the computer.

Abstract: A method and a multiprocessor computer for execution of the method. A first CPU has a general register file, an instruciton pipeline, and profile circuitry. The profile circuitry is operatively interconnected and under common hardware control with the instruction pipeline. The profile circuitry and instruction pipeline are cooperatively interconnected to detect the occurrence of profileable events occurring in the instruction pipeline. The profile circuitry is operable without software intervention to effect recording of profile information describing the profileable events into the general register file, without first capturing the information into a main memory of the computer. The recording is essentially concurrent with the occurrence of the profileable events.

Abstract: A method and a computer for execution of the method. As part of executing a stream of instructions, a series of memory loads is issued from a computer CPU to a bus, some directed to well-behaved memory and some directed to non-well-behaved devices in I/O space. Computer addresses are stored of instructions of the stream that issued memory loads to the non-well-behaved memory, the storage form of the recording allowing determination of whether the memory load was to well-behaved memory or not-well-behaved memory without resolution of any memory address stored in the recording.

Abstract: The present invention provides an apparatus and a method for variable size pages using fixed size TLB (Translation Lookaside Buffer) entries. In one embodiment, an apparatus for variable size pages using fixed size TLB entries includes a first TLB for fixed size pages and a second TLB for variable size pages. In particular, the second TLB stores fixed size TLB entries for variable size pages. Further, in one embodiment, an input of an OR device is connected to the second TLB to provide a cost-effective and efficient implementation for translating linear addresses to physical addresses using fixed size TLB entries stored in the second TLB.

Abstract: Apparatus and method for concurrent dispatch of instruction words which selectively comprise instruction components which are separately and substantially simultaneously received by distinct floating point and integer functional units. The instruction words are powers of 2 in length, (measured in terms of the smallest machine addressable unit) typically a 4 byte longword and an 8 byte quadword aligned to the natural boundaries also corresponding to powers of 2. To provide maximum operating efficiency, each functional (or processing) unit executes a component of an instruction word during an execution cycle. The type and length of the instruction word are indicated by one of the bit fields of the instruction word, which permits the apparatus to properly detect, store and transfer the instruction word to the appropriate functional unit.

Abstract: A method and apparatus for improving the efficiency of executing arithmetic and logical operations performed on arguments provided during the execution of computer instructions in which operands include a variable type argument or data portion accompanied by a tag identifier which defines the data type. The processing of the data is enhanced by the addition of two condition codes derived from the values of the pre-ALU tag identifiers and the post-ALU results. The condition codes allow rapid determination of data types without additional execution cycles or hardware overhead, resulting in enhanced execution of the instructions.