Abstract: Memory consistency is provided in an emulated processing environment. A processor architected with a weak memory consistency emulates an architecture having a firm memory consistency. This memory consistency is provided without requiring serialization instructions or special hardware.

Abstract: Instruction execution is facilitated by employing a buffer to handle instructions having special circumstances. When such an instruction is to be executed, a pointer of the instruction is directed to the buffer. The instruction is executed from the buffer and then the pointer is recovered to point to a location other than the buffer.

Abstract: A method, system, and computer program product for generating terminating, pseudo-random test instruction streams, including forward and backward branching instructions. A first instruction stream is generated, including at least one backward branching instruction and at least one forward branching instruction. Each backward branching instruction is preceded by at least one forward branching instruction, which is used to guarantee termination of the loop formed by the backward branching instruction. Backward branching targets are resolved when the backward branching instruction is inserted into the first instruction stream. Forward branching targets remain unresolved in the first instruction stream. A set of potential branch targets is determined for each forward branching instruction. For each forward branching instruction, a branch target is randomly selected from the set of potential branch targets for that forward branching instruction.

Abstract: A method, system and program product are provided for establishing one or more decimal floating point (DFP) operand for facilitating testing of a decimal floating point instruction. The method includes obtaining an encoded DFP operand previously generated for testing the decimal floating point instruction, and logically modifying at least one bit of the encoded DFP operand without decoding the encoded DFP operand to obtain an additional encoded DFP operand. In one embodiment, m sequential bits of the encoded DFP operand, n randomly generated bits (wherein n=m), and a logical operation (such as an AND, OR, XOR or SHIFT) are employed in modifying the previously generated, encoded DFP operand.

Abstract: Instruction execution is controlled by a single test that determines whether processing should continue in mainline processing or fall through to a test set. The single test compares a dynamically set variable to an instruction counter. If the test is met, mainline processing continues. Otherwise, processing falls through to a test set.

Abstract: A generalized trace and log facility is employed to collect data, including data associated with the first occurrence of an error. The facility provides standardized application programming interfaces to be used to collect data, print the data, and forward the data to a support team, if desired.

Abstract: Communication between processors and I/O communications processes is facilitated. During the communication, shared control blocks and input/output queues are updated without using locks. Instead, a lockless capability is provided to update the queues and control blocks, thereby enhancing system performance and minimizing the need for recovery processes.

Abstract: A data structure of readily accessible units of memory is provided. The data structure includes designations of one or more units of memory that while represented in the data structure do not need expensive address translation, other tests or special handling in order to access the units of memory. By employing such a data structure, memory access and system performance are enhanced.

Abstract: Optimizations are provided for processing environments. Selected memory objects are tagged with unique identifiers by an operating system of the environment, and those identifiers are used to manage processing within the environment. By detecting by a processing platform of the environment that a memory object has been tagged with a unique identifier, certain tasks may be bypassed and/or memory objects may be reused, even if located at a different location.

Abstract: Communication between processors and I/O communications processes is facilitated. During the communication, shared control blocks and input/output queues are updated without using locks. Instead, a lockless capability is provided to update the queues and control blocks, thereby enhancing system performance and minimizing the need for recovery processes.

Abstract: A generalized trace and log facility is employed to collect data, including data associated with the first occurrence of an error. The facility provides standardized application programming interfaces to be used to collect data, print the data, and forward the data to a support team, if desired.

Abstract: Memory consistency is provided in an emulated processing environment. A processor architected with a weak memory consistency emulates an architecture having a firm memory consistency. This memory consistency is provided without requiring serialization instructions or special hardware.

Abstract: An article of manufacture, method and system are provided for facilitating input/output (I/O) processing of at least one guest processing system. The article of manufacture includes at least one computer-usable medium having computer-readable program code logic to facilitate the I/O processing of the at least one guest processing system. The computer-readable program code logic when executing performing the following: emulating on a native system an I/O architecture for the at least one guest processing system, the emulating including: providing multiple device managers for a plurality of I/O devices of the I/O architecture; providing at least one communications adapter process interfacing the multiple device managers to the at least one network driver process; and wherein the multiple device managers translate I/O messages in at least one guest processing system format to messages in native system format for processing by the at least one communications adapter process, thereby facilitating I/O processing.

Abstract: A data structure of readily accessible units of memory is provided. The data structure includes designations of one or more units of memory that while represented in the data structure do not need expensive address translation, other tests or special handling in order to access the units of memory. By employing such a data structure, memory access and system performance are enhanced.

Abstract: Instruction execution is facilitated by employing a buffer to handle instructions having special circumstances. When such an instruction is to be executed, a pointer of the instruction is directed to the buffer. The instruction is executed from the buffer and then the pointer is recovered to point to a location other than the buffer.

Abstract: Instruction execution is controlled by a single test that determines whether processing should continue in mainline processing or fall through to a test set. The single test compares a dynamically set variable to an instruction counter. If the test is met, mainline processing continues. Otherwise, processing falls through to a test set.

Abstract: A technique for estimating and improving the test coverage for large machines, while accumulating minimum information of past test cases (i.e., minimum feedback) is provided. The technique is scalable in the sense that the number of machine instructions needed to measure the test coverage can range from a few instructions to all the instructions. The technique is easily integrated into existing test generation systems and is applicable to both uni- and multi-processing systems.

Abstract: A technique for estimating and improving the test coverage for large machines, while accumulating minimum information of past test cases (i.e., minimum feedback) is provided. The technique is scalable in the sense that the number of machine instructions needed to measure the test coverage can range from a few instructions to all the instructions. The technique is easily integrated into existing test generation systems and is applicable to both uni- and multi-processing systems.

Abstract: A technique for estimating and improving the test coverage for large machines, while accumulating minimum information of past test cases (i.e., minimum feedback) is provided. The technique is scalable in the sense that the number of machine instructions needed to measure the test coverage can range from a few instructions to all the instructions. The technique is easily integrated into existing test generation systems and is applicable to both uni- and multi-processing systems.

Abstract: A method, system and program product are provided for establishing one or more decimal floating point (DFP) operand for facilitating testing of a decimal floating point instruction. The method includes obtaining an encoded DFP operand previously generated for testing the decimal floating point instruction, and logically modifying at least one bit of the encoded DFP operand without decoding the encoded DFP operand to obtain an additional encoded DFP operand. In one embodiment, m sequential bits of the encoded DFP operand, n randomly generated bits (wherein n=m), and a logical operation (such as an AND, OR, XOR or SHIFT) are employed in modifying the previously generated, encoded DFP operand.