International Business Machines Corporation

Reid T Copeland

Marcel Mitran

Eric M Schwarz

Jonathan D Bradbury

Ali Ijaz Sheikh

Timothy John Slegel

Silvia Melitta Mueller

Steven R Carlough

Charles W Gainey, Jr

Theodore Joseph Bohizic

Petra Leber

Xin Guo

Carlos D Cavanna

Cedric Lichtenau

Chen Chen

Toshihiko Koju

Chad McIntyre

Christopher Eugene Bowler

Tommy U Hoffner

Tarique M Islam

Raúl E Silvera

Kerstin Claudia Schelm

Michael Klein

Allan Henry Kielstra

David Kevin Siegwart

Jordan Ryan Zannier

Vijay Sundaresan

Bruce C Giamei

Mark Graham Stoodley

Andrew Johnson

Stefan Payer

Andreas Wagner

Trong Truong

Patrick R Doyle

Steven Cooper

Iain Alexander Ireland

Roger H E Pett

Charles Brian Hall

Kirk A Stewart

Chad Mc Intyre

Ning Thomas Wong

Patrick Doyle

Charles Hall

An instruction to perform validity testing of a source value is executed. The executing the instruction includes obtaining the source value using at least one field of the instruction and obtaining a plurality of test controls using a field of the instruction. The one or more test controls of the plurality of test controls are used to specify which digit positions of the source value are to be tested for validity and what codes are valid codes for the digit positions specified to be tested. Validity testing of at least a portion of the source value is performed based on the plurality of test controls obtained using the field of the instruction, and the performing the validity testing provides a result. The result is provided for use in further processing.

Vector test decimal instruction for validity testing

A method, system, and computer-readable medium for binary translation cause a binary translator to combine raw binary code and compiler-produced metadata associated with a compiled program module. The binary translator is caused to further reconcile, using the compiler-produced metadata, original compiler-produced control flow information with how lower-level machine instructions comprise a control flow in the raw binary code, and original compiler-produced aliasing information with how lower-level machine instructions access the memory locations described by the aliasing information according to predetermined criteria. The binary translator further caused to prevent, copy propagation of values in temporary variables for decimal computations beyond offsets in the machine instructions where the temporary variables are killed. The binary translator further caused to remove identified dead store instructions, and to generate a new compiled program module comprising an optimized version of the compiled program module having strict compatibility to an original version of the compiled program module.

Binary translation using raw binary code with compiler produced metadata

An instruction to perform converting and scaling operations is provided. Execution of the instruction includes converting an input value in one format to provide a converted result in another format. The converted result is scaled to provide a scaled result. A result obtained from the scaled result is placed in a selected location. Further, an instruction to perform scaling and converting operations is provided. Execution of the instruction includes scaling an input value in one format to provide a scaled result and converting the scaled result from the one format to provide a converted result in another format. A result obtained from the converted result is placed in a selected location.

Vector convert hexadecimal floating point to scaled decimal instruction

Instruction interrupt suppression for an overflow condition. An instruction is executed, and a determination is made that an overflow condition occurred. Based on a per-instruction overflow interrupt indicator being set to a defined value, interrupt processing for the overflow condition is performed, and based on the per-instruction overflow interrupt indicator being set to another defined value, the interrupt processing for the overflow condition is bypassed.

Instruction interrupt suppression of overflow exception

Dataflow optimization by dead store elimination focusing on logically dividing a contiguous storage area into different portions by use to allow a different number and type of dataflow and dead store techniques on each portion. A first storage portion, containing the storage for control flow related metadata, is split from a remaining storage portion. Liveness analysis is executed on the first storage portion using bitvectors with each bit representing four bytes. The remaining storage portion, containing the temporary storage for computational values, is processed using a deadness-range-based dataflow analysis. IN and OUT sets for each basic block are generated by processing blocks GEN and KILL sets by performing a backwards intersection dataflow analysis. Stores that write to the set of dead ranges in the IN sets of blocks are eliminated as dead stores.

Eliminating dead stores

An instruction to perform an operation selected from a plurality of operations configured for the instruction is executed. The executing includes determining a value of a selected operand of the instruction. The determining the value is based on a control of the instruction and includes reading the selected operand of the instruction from a selected operand location to obtain the value of the selected operand, based on the control having a first value, and using a predetermined value as the value of the selected operand, based on the control having a second value. The value and another selected operand of the instruction are multiplied to obtain a product. An arithmetic operation is performed using the product and a chosen operand of the instruction to obtain an intermediate result. A result from the intermediate result is obtained and placed in a selected location.

Hexadecimal floating point multiply and add instruction

Vector pack and unpack instructions are described. An instruction to perform a conversion between one decimal format and another decimal format is executed, in which the one decimal format or the other decimal format is a zoned decimal format. The executing includes obtaining a value from at least one register specified using the instruction. At least a portion of the value is converted from the one decimal format to the other decimal format different from the one decimal format to provide a converted result. A result obtained from the converted result is written into a single register specified using the instruction.

Vector pack and unpack instructions

An instruction to perform scaling, converting and splitting operations is executed. The executing the instruction includes scaling an input value in one format to provide a scaled result. The scaled result is converted from the one format to provide a converted result in another format. The converted result is split into multiple parts, and one or more parts of the multiple parts are placed in a selected location.

Decimal scale and convert and split to hexadecimal floating point instruction

Digit validation check control for execution of an instruction. A process obtains an instruction to perform operation(s) using input value(s). The instruction includes a no validation indicator for controlling whether digit validation check control is enabled for execution of the instruction. The process executes the instruction, including determining, based on the no validation indicator, whether digit validation check control is enabled for execution of the instruction, and performing processing based on the determining. Based on the no validation indicator being set to a defined value, digit validation check control is enabled and the processing includes forcing a digit check error indicator output by the executing to indicate no digit check error with respect to the at least one input value.

Digit validation check control in instruction execution

A method and systems generate a control flow graph including an edge of the control flow graph from a branch instruction to a target address of the branch instruction in an abstract interpretation for an assignment instruction to a branch target variable of a program. The program allocates a particular branch target variable to a branch instruction having a plurality of branch targets. The branch target address is loaded from the branch target variable upon branching, a branch address of a branch instruction having one branch target as well as the address assigned by the assignment instruction to the branch target variable being determined as certain constant values determined by compiling the program. The target address assigned by the assignment instruction is added to an object of the abstract interpretation. A current abstract interpretation is terminated if the abstract interpretation reaches an instruction already subjected to the abstract interpretation.

Control flow graph analysis

Negative zero control for execution of an instruction. A process obtains an instruction to perform operation(s) using an input value. The instruction includes a negative zero control indicator indicating whether negative zero control is enabled for execution of the instruction. The process executes the instruction, the executing including performing the operation(s) using the input value to obtain a result having a sign, determining whether to control the sign of the result, the determining being based at least in part on the negative zero control indicator being set to a defined value, and performing further processing, as part the executing the instruction, based on the determining.

Negative zero control in instruction execution

Branch instructions are managed in an emulation environment that is executing a program. A plurality of slots in a Polymorphic Inline Cache is populated. A plurality of entries is populated in a branch target buffer residing within an emulated environment in which the program is executing. When an indirect branch instruction associated with the program is encountered, a target address associated with the instruction is identified from the indirect branch instruction. At least one address in each of the slots of the Polymorphic Inline Cache is compared to the target address associated with the indirect branch instruction. If none of the addresses in the slots of the Polymorphic Inline Cache matches the target address associated with the indirect branch instruction, the branch target buffer is searched to identify one of the entries in the branch target buffer that is associated with the target address of the indirect branch instruction.

Branch target buffer for emulation environments

An instruction generates a value for use in processing within a computing environment. The instruction obtains a sign control associated with the instruction, and shifts an input value of the instruction in a specified direction by a selected amount to provide a result. The result is placed in a first designated location in a register, and the sign, which is based on the sign control, is placed in a second designated location of the register. The result and the sign provide a signed value to be used in processing within the computing environment.

Decimal load immediate instruction

A method for automatic verification of optimization of high level constructs includes generating a first executable code by compiling a computer program that includes a high level construct. The compiling includes generating a first set of machine instructions for the high level construct and storing compile-time information for the high level construct. The method further includes optimizing the first executable code which includes converting the first executable code into an intermediate language representation. The optimization further includes generating a second executable code. For this, the method includes generating a second set of machine instructions for the high level construct from the intermediate language representation. If the behavior of the first set of machine instructions and the second set of machine instructions matches, the second set of machine instructions is included in the second executable code, otherwise the first set of machine instructions is included.

Automatic verification of optimization of high level constructs using test vectors

Machine instructions, referred to herein as a long Convert from Zoned instruction (CDZT) and extended Convert from Zoned instruction (CXZT), are provided that read EBCDIC or ASCII data from memory, convert it to the appropriate decimal floating point format, and write it to a target floating point register or floating point register pair. Further, machine instructions, referred to herein as a long Convert to Zoned instruction (CZDT) and extended Convert to Zoned instruction (CZXT), are provided that convert a decimal floating point (DFP) operand in a source floating point register or floating point register pair to EBCDIC or ASCII data and store it to a target memory location.

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Markham, Canada

Reid T Copeland