Compiler improves COBOL application performance and developer productivity
The IBM® COBOL for OS/390® & VM compiler helps you simplify common programming tasks and improve the performance of your COBOL applications. It provides 31-digit decimal data support and TRUNC(BIN) performance enhancements. Now your COBOL applications can exploit the open network computing environment, making COBOL a more powerful application development tool.
COBOL for OS/390 & VM provides:
- TRUNC(BIN) compiler option—improves the performance of operations on binary data that require binary truncation, rather than the standard COBOL truncation at base-10 picture descriptions.
- Production debugging—supports the IBM MVS™/TSO, IBM OS/390 UNIX® and IBM CICS® environments.
- IBM DB2® coprocessor integration—supports both native COBOL and embedded SQL statements in the source program.
- OS/390 UNIX System Services—supports application development and execution in the OS/390 UNIX System Services environment.
- Improved application developer productivity—provides a set of intrinsic functions and IBM Language Environment services.
TRUNC(BIN) compiler option
- Performance improvements primarily apply to halfword and fullword binary data and to COBOL applications running on complementary metal-oxide semiconductor (CMOS) processors.
- Data items declared with the USAGE COMP-5 data type are represented in storage as binary data. They can contain values of magnitude up to the capacity of the native binary representation: 2, 4 or 8 bytes.
- With USAGE COMP-5, data values are not limited to the value implied by the number of nines in the picture for the item.
- The debug tool, a robust mainframe interactive (MFI) interlanguage tool, supports COBOL, PL/I and C/C++. Debugging COBOL applications that run in the OS/390 UNIX environment is easier using the debug tool and the remote interface.
- You can improve performance by enabling COBOL programs to use overlay hooks rather than compiled-in hooks.
- By choosing to generate the COBOL symbolic debugging information in a file separate from the object module, you can avoid large memory requirements for load modules in production.
DB2 coprocessor integration
- When the compiler encounters SQL statements, it interfaces with the DB2 coprocessor. The DB2 coprocessor takes appropriate action and returns any native language statements that must be generated to the compiler.
- The coprocessor helps improve usability, particularly interactive debugging. You can debug the application at the original source level, rather than the level of the expanded source produced by the DB2 precompiler.
- SQL statements can be used in COPY books. REPLACE statements can have an effect on SQL statements.
OS/390 UNIX System Services Support
- You can run an OS/390 UNIX COBOL application in the following OS/390 UNIX execution environments: OS/390 shell, OS/390 ISPF shell, Time Sharing Option Extensions and OS/390 batch.
- COBOL programs can call the standard UNIX and POSIX functions, which are shipped as part of the OS/390 Language Environment component.
- COBOL programs running under OS/390 UNIX can access both HFS files and MVS data sets.
- HFS support during development is provided for COBOL source files, COPY books, object modules, listings, Interface Definition Language (IDL) files, associated data (ADATA) files and executable modules.
- HFS files can be used in COPY and BASIS statements. The cob2 command compiles and links COBOL programs within the OS/390 UNIX shell.
Improved application developer productivity
- Intrinsic functions include string handling, financial capabilities, statistical functions and mathematical formulas.
- The COBOL CALL statement lets you take advantage of Language Environment services for everything from storage management to condition handling.
- The condition handling support enables you to write programs in which error handling is done in a separate routine that is loaded only when needed. You can write the error-handling routines in COBOL.
- COBOL for OS/390 & VM supports QSAM tape files up to 2 GB. It has a compiler option (DIAGTRUNC) that supports diagnosis of moves that result in numeric truncation.
- COBOL for OS/390 & VM enables linkage of COBOL applications using the DFSMS binder alone. The prelinker is only required in exceptional cases under CICS.
COBOL for OS/390 & VM resources