Abstract: Mechanisms are provided for dynamically rewriting branch instructions in a portion of code. The mechanisms execute a branch instruction in the portion of code. The mechanisms determine if a target instruction of the branch instruction, to which the branch instruction branches, is present in an instruction cache associated with the processor. Moreover, the mechanisms directly branch execution of the portion of code to the target instruction in the instruction cache, without intervention from an instruction cache runtime system, in response to a determination that the target instruction is present in the instruction cache. In addition, the mechanisms redirect execution of the portion of code to the instruction cache runtime system in response to a determination that the target instruction cannot be determined to be present in the instruction cache.

Abstract: Mechanisms for performing decoding of context-adaptive binary arithmetic coding (CABAC) encoded data. The mechanisms receive, in a first single instruction multiple data (SIMD) vector register of the data processing system, CABAC encoded data of a bit stream. The CABAC encoded data includes a value to be decoded and bit stream state information. The mechanisms receive, in a second SIMD vector register of the data processing system, CABAC decoder context information. The mechanisms process the value, the bit stream state information, and the CABAC decoder context information in a non-recursive manner to generate a decoded value, updated bit stream state information, and updated CABAC decoder context information. The mechanisms store, in a third SIMD vector register, a result vector that combines the decoded value, updated bit stream state information, and updated CABAC decoder context information. The mechanisms use the decoded value to generate a video output on the data processing system.

Abstract: Mechanisms are provided for rewriting branch instructions in a portion of code. The mechanisms receive a portion of source code having an original branch instruction. The mechanisms generate a branch stub for the original branch instruction. The branch stub stores information about the original branch instruction including an original target address of the original branch instruction. Moreover, the mechanisms rewrite the original branch instruction so that a target of the rewritten branch instruction references the branch stub. In addition, the mechanisms output compiled code including the rewritten branch instruction and the branch stub for execution by a computing device. The branch stub is utilized by the computing device at runtime to determine if execution of the rewritten branch instruction can be redirected directly to a target instruction corresponding to the original target address in an instruction cache of the computing device without intervention by an instruction cache runtime system.

Abstract: An application thread executes a direct branch instruction that is stored in an instruction cache line. Upon execution, the direct branch instruction branches to a branch descriptor that is also stored in the instruction cache line. The branch descriptor includes a trampoline branch instruction and a target instruction space address. Next, the trampoline branch instruction sends a branch descriptor pointer, which points to the branch descriptor, to an instruction cache manager. The instruction cache manager extracts the target instruction space address from the branch descriptor, and executes a target instruction corresponding to the target instruction space address. In one embodiment, the instruction cache manager generates a target local store address by masking off a portion of bits included in the target instruction space address. In turn, the application thread executes the target instruction located at the target local store address accordingly.

Abstract: A method for computing includes executing a program, including multiple cacheable lines of executable code, on a processor having a software-managed cache. A run-time cache management routine running on the processor is used to assemble a profile of inter-line jumps occurring in the software-managed cache while executing the program. Based on the profile, an optimized layout of the lines in the code is computed, and the lines of the program are re-ordered in accordance with the optimized layout while continuing to execute the program.

Abstract: Mechanisms are provided for rewriting branch instructions in a portion of code. The mechanisms receive a portion of source code having an original branch instruction. The mechanisms generate a branch stub for the original branch instruction. The branch stub stores information about the original branch instruction including an original target address of the original branch instruction. Moreover, the mechanisms rewrite the original branch instruction so that a target of the rewritten branch instruction references the branch stub. In addition, the mechanisms output compiled code including the rewritten branch instruction and the branch stub for execution by a computing device. The branch stub is utilized by the computing device at runtime to determine if execution of the rewritten branch instruction can be redirected directly to a target instruction corresponding to the original target address in an instruction cache of the computing device without intervention by an instruction cache runtime system.

Abstract: Mechanisms are provided for arranging binary code to reduce instruction cache conflict misses. These mechanisms generate a call graph of a portion of code. Nodes and edges in the call graph are weighted to generate a weighted call graph. The weighted call graph is then partitioned according to the weights, affinities between nodes of the call graph, and the size of cache lines in an instruction cache of the data processing system, so that binary code associated with one or more subsets of nodes in the call graph are combined into individual cache lines based on the partitioning. The binary code corresponding to the partitioned call graph is then output for execution in a computing device.

Abstract: Mechanisms are provided for dynamically rewriting branch instructions in a portion of code. The mechanisms execute a branch instruction in the portion of code. The mechanisms determine if a target instruction of the branch instruction, to which the branch instruction branches, is present in an instruction cache associated with the processor. Moreover, the mechanisms directly branch execution of the portion of code to the target instruction in the instruction cache, without intervention from an instruction cache runtime system, in response to a determination that the target instruction is present in the instruction cache. In addition, the mechanisms redirect execution of the portion of code to the instruction cache runtime system in response to a determination that the target instruction cannot be determined to be present in the instruction cache.

Abstract: Mechanisms are provided for evicting cache lines from an instruction cache of the data processing system. The mechanisms store, for a portion of code in a current cache line, a linked list of call sites that directly or indirectly target the portion of code in the current cache line. A determination is made as to whether the current cache line is to be evicted from the instruction cache. The linked list of call sites is processed to identify one or more rewritten branch instructions having associated branch stubs, that either directly or indirectly target the portion of code in the current cache line. In addition, the one or more rewritten branch instructions are rewritten to restore the one or more rewritten branch instructions to an original state based on information in the associated branch stubs.

Abstract: A compiler of a single instruction multiple data (SIMD) information handling system (IHS) identifies “if-then-else” statements that offer opportunity for conditional branch conversion. The compiler converts those “if-then-else” statements into “conditional branch and prepare” statements as well as “branch return” statements. The compiler compiles source code file information containing “if-then-else” statement opportunities into compiled code, namely an executable program. The SIMD IHS employs a processor or processors to execute the executable program. During execution, the processor generates and updates SIMD lane mask information to track and manage the conditional branch loops of the executing program. The processor saves branch addresses and employs SIMD lane masks to identify conditional branch loops with different branch conditions than previous conditional branch loops. The processor may reduce SIMD IHS processing time during processing of compiled code of the original “if-then-else” statements.

Abstract: A system comprises a memory module configured to store signed page table data and a selected processing element coupled to the memory module. The selected processing element is one of a plurality of processing elements, which together comprise a portion of a multiprocessor system. The selected processing element is configured to authenticate page table management code and, based on authenticated page table management code, to sign page table data that is subsequently stored in the memory module, and to verify signed page table data that is read from the memory module.

Abstract: Mechanisms for performing decoding of context-adaptive binary arithmetic coding (CABAC) encoded data. The mechanisms receive, in a first single instruction multiple data (SIMD) vector register of the data processing system, CABAC encoded data of a bit stream. The CABAC encoded data comprises a value to be decoded and bit stream state information. The mechanisms receive, in a second SIMD vector register of the data processing system, CABAC decoder context information. The mechanisms process the value, the bit stream state information, and the CABAC decoder context information in a non-recursive manner to generate a decoded value, updated bit stream state information, and updated CABAC decoder context information. The mechanisms store, in a third SIMD vector register, a result vector that combines the decoded value, updated bit stream state information, and updated CABAC decoder context information. The mechanisms use the decoded value to generate a video output on the data processing system.

Abstract: The illustrative embodiments comprise a method, data processing system, and computer program product having a processor unit for processing instructions with loops. A processor unit creates a first group of instructions having a first set of loops and second group of instructions having a second set of loops from the instructions. The first set of loops have a different order of parallel processing from the second set of loops. A processor unit processes the first group. The processor unit monitors terminations in the first set of loops during processing of the first group. The processor unit determines whether a number of terminations being monitored in the first set of loops is greater than a selectable number of terminations. In response to a determination that the number of terminations is greater than the selectable number of terminations, the processor unit ceases processing the first group and processes the second group.

Abstract: Mechanisms are provided for evicting cache lines from an instruction cache of the data processing system. The mechanisms store, for a portion of code in a current cache line, a linked list of call sites that directly or indirectly target the portion of code in the current cache line. A determination is made as to whether the current cache line is to be evicted from the instruction cache. The linked list of call sites is processed to identify one or more rewritten branch instructions having associated branch stubs, that either directly or indirectly target the portion of code in the current cache line. In addition, the one or more rewritten branch instructions are rewritten to restore the one or more rewritten branch instructions to an original state based on information in the associated branch stubs.

Abstract: Mechanisms are provided for rewriting branch instructions in a portion of code. The mechanisms receive a portion of source code having an original branch instruction. The mechanisms generate a branch stub for the original branch instruction. The branch stub stores information about the original branch instruction including an original target address of the original branch instruction. Moreover, the mechanisms rewrite the original branch instruction so that a target of the rewritten branch instruction references the branch stub. In addition, the mechanisms output compiled code including the rewritten branch instruction and the branch stub for execution by a computing device. The branch stub is utilized by the computing device at runtime to determine if execution of the rewritten branch instruction can be redirected directly to a target instruction corresponding to the original target address in an instruction cache of the computing device without intervention by an instruction cache runtime system.

Abstract: Mechanisms are provided for dynamically rewriting branch instructions in a portion of code. The mechanisms execute a branch instruction in the portion of code. The mechanisms determine if a target instruction of the branch instruction, to which the branch instruction branches, is present in an instruction cache associated with the processor. Moreover, the mechanisms directly branch execution of the portion of code to the target instruction in the instruction cache, without intervention from an instruction cache runtime system, in response to a determination that the target instruction is present in the instruction cache. In addition, the mechanisms redirect execution of the portion of code to the instruction cache runtime system in response to a determination that the target instruction cannot be determined to be present in the instruction cache.

Abstract: Mechanisms are provided for arranging binary code to reduce instruction cache conflict misses. These mechanisms generate a call graph of a portion of code. Nodes and edges in the call graph are weighted to generate a weighted call graph. The weighted call graph is then partitioned according to the weights, affinities between nodes of the call graph, and the size of cache lines in an instruction cache of the data processing system, so that binary code associated with one or more subsets of nodes in the call graph are combined into individual cache lines based on the partitioning. The binary code corresponding to the partitioned call graph is then output for execution in a computing device.

Abstract: A cache manager receives a request for data, which includes a requested effective address. The cache manager determines whether the requested effective address matches a most recently used effective address stored in a mapped tag vector. When the most recently used effective address matches the requested effective address, the cache manager identifies a corresponding cache location and retrieves the data from the identified cache location. However, when the most recently used effective address fails to match the requested effective address, the cache manager determines whether the requested effective address matches a subsequent effective address stored in the mapped tag vector. When the cache manager determines a match to a subsequent effective address, the cache manager identifies a different cache location corresponding to the subsequent effective address and retrieves the data from the different cache location.

Abstract: An application thread executes a direct branch instruction that is stored in an instruction cache line. Upon execution, the direct branch instruction branches to a branch descriptor that is also stored in the instruction cache line. The branch descriptor includes a trampoline branch instruction and a target instruction space address. Next, the trampoline branch instruction sends a branch descriptor pointer, which points to the branch descriptor, to an instruction cache manager. The instruction cache manager extracts the target instruction space address from the branch descriptor, and executes a target instruction corresponding to the target instruction space address. In one embodiment, the instruction cache manager generates a target local store address by masking off a portion of bits included in the target instruction space address. In turn, the application thread executes the target instruction located at the target local store address accordingly.

Abstract: A method for computing includes executing a program, including multiple cacheable lines of executable code, on a processor having a software-managed cache. A run-time cache management routine running on the processor is used to assemble a profile of inter-line jumps occurring in the software-managed cache while executing the program. Based on the profile, an optimized layout of the lines in the code is computed, and the lines of the program are re-ordered in accordance with the optimized layout while continuing to execute the program.