C++ Compiler

• Improved support for volatile data references, forcing them to be in memory and loaded/stored at each reference.

• Support for XPLINK linkages in IBM compatibility mode.

• Support for later versions of IBM compatibility, including support through z/OS 1.7. This also includes newer IBM predefined macros.

• Improved compile time for large programs with large amounts of constant data.

• New optimizations, including improved constant propogation and basic-block related optimizations.

• Improved code generation, particularly when -march=esa390 or later is enabled.

• Added support for IBM-style "events file" for use with the IBM TPF Toolkit.

• Support Microsoft's __int8/__int16/__int32 and __int64 builtin types.

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  What is new in Release 1.80 of Systems/C++

  C++ Library

  • Updated to version 4.6.2 of the industry-standard STLPort library.

  C++ Compiler

  • New -fpack option to specify per-compilation structure member alignment.
  • Support for reading #include files from PDS members under OpenEdition.
  • Support for -frsa=NNN to provide the user a mechanism for defining the per-function register-save-area.
  • Support for IBM compatible namespaces if -fc370=z1r2i (or later) is enabled.
  • Support for extern "OS" and extern "PLI" linkages.
  • Support for 128-bit (long double) data type.
  • New -march=esa390 option; causes the compiler to use halfword immediate instructions, use string instructions and to assume 16 floating-pt registers. Enabled by default with -flinux is specified.
  • New state-of-the-art register allocation algorithms, greatly improving register use in the generated code.

  Other Enhancements

  For other enhancements to the utilities and runtime library, see the DCC "whatsnew" description.

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  What is new in Release 1.76 of Systems/C++
  • Version 1.76 is a maintenance release for C++.

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  What is new in Release 1.75 of Systems/C++

  C++ compiler:

  • Support for the __rent and __norent keywords applied to data.
  • If -march=zarch is specified, the compiler will predefine the macro _LP64 to 1; otherwise, it defines the _ILP32 macro to 1.
  • Constant modulus by power-of-two (either signed or unsigned) is now optimized in the code-generator.
  • When -fc370 is not specified, the compiler recognizes #pragma pack(pop) as a equivalent to #pragma pack(reset).
  • Compiler was changed to define the name of the function (in Systems/C mode) in a compiler-generated character string that preceeds the function prologue. Then, a new LNAMEADDR= parameter was added to DCCPRLG which provides the label for this string. This allows the string to be as long as necessary, and contain any required bytes, and also be properly demangled in the C++ case. With this change, the results of a call to __traceback are much better.
  • New -fc370=z1r2 option, to indicate compatibility with the IBM V1R2 z/OS compiler.
  • New -fptr_to_unsized_array_parm option, to allow for compatibility with compilers that incorrectly allow this in C++ source (e.g. SAS/C++ and Microsoft.)
  • Improved code generation for passing constant parameters to functions, particularly in Linux mode.
  • In conjunction with the library, changed the name that is saved in the Systems/C prologue to be the de-mangled C++ name, along with removing the extraneous $s.

  Other enhancements

  For enhancements to the utilities and runtime library, see the DCC "whatsnew" description.

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  What is new in Release 1.70 of Systems/C++

  Utilities:

  • PLINK supplied with Systesm/C has been rewritten to better support automatic template instantiation. The C++ compiler now generates weakly defined functions for template instantiations. During the PLINK step, duplicate definitions of these weakly defined functions are eliminated.

    This allows version 1.70 of Systems/C++ to provide much better management of automatic template instantiation; without the need for "side files", or bloated executables.

  Compilers:

  • New -finstrument_functions option. For Linux (-flinux), this decorates function entry/exit points compatibly with the normal Linux utilities. In Systems/C mode, this causes macros to be generated a function entry/exit points.
  • New -fstructmap/-fno_structmap option to enable/disable the "structure map" portion of the listing.
  • New -fasmcomm option in the C++ compiler, which describes how the original C++ lines should appear in the generated assembler output.
  • New -fasmlnno option in the C++ compiler. This causes the codegenerator to generate comments detailing the line number in the generated assembler source.
  • New -fflex, -fmin_lm_reg=X and -fmin_stm_reg=X options in the C and C++ compiler. These control peepholing of consecutive Load/STore instructions. On the FLEX/ES(tm) system, LM and STM instructions can perform slower than the sequence of L/ST instructions.
  • New -fopts[=macro] and -fendmacro[=text] option in the C++ compiler.
  • New -fexportall option in C++ compiler (in IBM mode.)
  • New -fdollar option in the C++ compiler - allows '$' in identifiers.
  • Improved code generation in testing "flag" bytes, unsigned char operations and unsigned int operations.
  • Code generation improvements to add new options to the prologue/epilogue to not save/restore as many registers (or, possibly no saving/restoring of registers.) Also, improvements to reduce the local DSA requirements.
  • Improvements in constant multiplication evaluation to avoid unnecessary register copies.
  • Linux prologue/epilogue improvements.

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  What is new in Release 1.65 of Systems/C++

  Compiler:

  • Improved inlining, the compiler can now inline functions which were not previously inlined.
  • Operator keywords supported in #if directives e.g. #if 0 or 1
  • Value-initialization implemented.
  • Many front-end improvements, including performance improvements, diagnostic improvements and listing file improvements.
  • Support for #pragma ident and #ident which place text characters into the generated object.
  • -O option to engage optimizations.
  • Improved register tracking in the code generator, providing faster runtime performance.

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  What is new in Release 1.60 of Systems/C++

  As well as the new features of the C compiler , Systems/C++ V1.60 provides the following enhancements

  Compiler:

  • -fquiet option, which suppresses the banner messages
  • -march=zarch option:
    True 64-bit compiler using "Grande" instructions
    extern "align4" linkage for C++
    Uses all 16 floating point registers for improved math code.
    Takes advantage immediate instructions
    New -famode=any to support using Grande instructions and 64-bit integers/pointers when the execution AMODE may not be 64-bits.
  • __ptr31/__ptr64 pointer type qualifiers, for specifically declaring 32 (31) bit or 64 bit pointers, no matter what type of code is being compiled.
  • switch() statements extended to support long-long integral values when -fc99 not enabled
  • -fc370 now supports the following IBM builtin functions: alloca, tsched, cs, cds. Thus, all of the documented IBM C builtin functions are now supported.
  • export supported in IBM compatiblity mode
  • C++ compiler now includes a structure map in the listing file.
  • Enhanced debugging information support for C and C++ compilers in -flinux mode. C and C++ code compiled with -flinux is now directly debuggable by the Linux debugger gdb.
  • Support for -fpic and -fPIC for Linux/390 and z/Linux.
  • Continued "general" code-generation improvements.
  • z/Linux and OS/390 USS (OpenEdition) are now supported platforms.

  C++ Library:

  • New z/Architecture rent and non-rent libraries, allowing stack/heap/PRV above-the-bar, user-configurable.
  • Non z/Architecture library now supports stack/heap/PRV above-the-line, user-configurable.
  • Runtime support for executing C programs on MVS 3.8. at program startup for non-DCALL programs.

  Documentation:

  • Documentation PDFs now include a table of context with links into the documentation sections, and links within the document to interesting sections.