Techniques for signal handling between programs associated with different addressing modes in a computer system are described herein. An aspect includes, based on a signal occurring during execution of a first program in a first runtime environment, wherein the first program and the first runtime environment are associated with a first addressing mode, invoking a first signal exit routine associated with the first addressing mode. Another aspect includes allocating a signal information area (SIA) by the first signal exit routine. Another aspect includes calling a second signal exit routine associated with a second addressing mode that is different from the first addressing mode with an address of the SIA. Another aspect includes allocating a mirror SIA by the second signal exit routine. Another aspect includes handling the signal, and resuming execution based on the handling of the signal.

Apparatus comprises a processor to execute program instructions stored at respective memory addresses, processing of the program instructions being constrained by a prevailing capability defining at least access permissions to a set of one or more memory addresses; the processor comprising: control flow change handling circuitry to perform a control flow change operation, the control flow change operation defining a control flow change target address indicating the address of a program instruction for execution after the control flow change operation; and capability generating circuitry to determine, in dependence on the control flow change target address, an address at which capability access permissions data is stored; the capability generating circuitry being configured to retrieve the capability access permissions data and to generate a capability for use as a next prevailing capability in dependence upon at least the capability access permissions data.

The invention relates to the technical field of a processor, in particular to a method for parallel extracting instructions and a readable storage medium. The method generates a valid vector of fetched instructions according to the end position vector s_mark_end of the instruction, and performs parallel decoding of instructions at each position, calculation of instruction address and branch instruction target address operation through logical “AND” and logical “OR” operations. Ultimately, multiple instructions are fetched in parallel. The present invention is a method for generating a valid vector of fetching instructions according to the end position vector s_mark_end of the instruction, and extracting multiple instructions in parallel through logical “AND” and logical “OR” operations. The invention can extract a plurality of instructions in parallel, there is no serial dependence relationship between each instruction, and the time sequence is easy to converge, so a higher main frequency can be obtained.

A method and system for moving data from a source memory to a destination memory by a processor is disclosed herein. The destination memory stores a sequence of instructions and the sequence of instructions comprises one or more load instructions and one or more store instructions. The processor initially moves the one or more store instructions from the destination memory to the source memory. The processor then executes the one or more load instructions from the destination memory. On executing the one or more load instructions, the data is loaded from the source memory to at least one register in the processor. The processor further initiates execution of the one or more store instructions stored in the source memory. On executing the one or more store instructions from the source memory, the processor stores the data from the at least one register to the destination memory.

Systems, apparatuses, and methods for efficient handling of subroutine epilogues. When an indirect control transfer instruction corresponding to a procedure return for a subroutine is identified, the return address and a signature are retrieved from one or more of a return address stack and the memory stack. An authenticator generates a signature based on at least a portion of the retrieved return address. While the signature is being generated, instruction processing speculatively continues. No instructions are permitted to commit yet. The generated signature is later compared to a copy of the signature generated earlier during the corresponding procedure call. A mismatch causes an exception.

Methods, systems and apparatuses for processing a plurality of threads of a single-instruction multiple data (SIMD) group are disclosed. One method includes initializing a current instruction pointer of the SIMD group, initializing a thread instruction pointer for each of the plurality of threads of the SIMD group including setting a flag for each of the plurality of threads, determining whether a current instruction of the processing includes a conditional branch, resetting a flag of each thread of the plurality of threads that fails a condition of the conditional branch, and setting the thread instruction pointer for each of the plurality of threads that fails the condition of the conditional branch to a jump instruction pointer, and incrementing the current instruction pointer and each thread instruction pointer of the threads that do not fail, if at least one of the threads do not fail the condition.

Methods and apparatus for identifying an effective address (EA) using an interrupt instruction tag (ITAG) in a multi-slice processor including receiving, by an instruction fetch unit of the processor, the interrupt ITAG; retrieving an effective address table (EAT) row from an EAT, wherein the EAT row comprises a range of EAs and a first ITAG of a range of ITAGs; accessing a processor instruction vector comprising a plurality of elements, each element corresponding to one of a plurality of ITAGs; applying a mask to the processor instruction vector to obtain a portion of the processor instruction vector that begins with an element corresponding to the first ITAG and is defined by an element corresponding to the interrupt ITAG; calculating an EA offset; and identifying the EA for the interrupt ITAG using the EA offset and the range of EAs in the retrieved EAT row.

Technologies for indirect branch target security include a computing device having a processor to execute an indirect branch instruction. The processor may determine an indirect branch target of the indirect branch instruction, load a memory tag associated with the indirect branch target, and determine whether the memory tag is set. The processor may generate a security fault if the memory tag is not set. The processor may load an encrypted indirect branch target, decrypt the encrypted branch target using an activation record key stored in an activation key register, and perform a jump to the indirect branch target. The processor may generate a next activation record coordinate as a function of the activation record key and a return address of a call instruction and generate the next activation record key as a function of the next activation record coordinate. Other embodiments are described and claimed.

A technique for operating a processor includes identifying a difficult branch instruction (branch) whose target address (target) has been mispredicted multiple times. Information about the branch (which includes a current target and a next target) is learned and stored in a data structure. In response to the branch executing subsequent to the storing, whether a branch target of the branch corresponds to the current target in the data structure is determined. In response to the branch target of the branch corresponding to the current target of the branch in the data structure, the next target of the branch that is associated with the current target of the branch in the data structure is determined. In response to detecting that a next instance of the branch has been fetched, the next target of the branch is utilized as the predicted target for execution of the next instance of the branch.

A processor can be used to ensure that program code can only be used for a designed purpose and not exploited by malware. Embodiments of an illustrative processor can comprise logic operable to execute a program instruction and to distinguish whether the program instruction is a legitimate branch instruction or a non-legitimate branch instruction.