The product is regrettably yet another piece of Borland vapourware with no firm delivery date yet set, but Borland International Inc reckons that its new Turbo C will be worth the wait (CI No 607). It claims that its high-speed Turbo C is the only optimising C compiler for microcomputers that provides end users with a choice of using either the integrated environment complete with built-in editor, compiler and linker; or a conventional-style command line interface. Turbo C provides a one-pass compiler, control of memory models and code optimisations. In benchmark tests, Borland claims that Turbo C generates the fastest, smallest object code of any C compiler. The compiler has a built-in Turbo Linker, also provided as a stand-alone program for use in the command line mode, and is a single-pass compiler that generates intermediate data structures in memory. In contrast, most C compilers are four- or five-pass compilers that compile using temporary files on disk. It compiles to memory at fast raw compile times exceeding 7,000 lines per minute on a 6MHz IBM AT and it supports six memory models: tiny, small, compact, medium, large, huge. Near pointers and far pointers are used as well as a fast linker like that implemented in Turbo Prolog. The Turbo linker is compatible with the PC-DOS linker and links approximately two to 10 times faster than the PC-DOS one, while it is about one-fifth the size. Turbo C features a built-in LINT for error checking for development and debugging, with support of ANSI prototypes. A range of compiler options are provided including inline assembler; multiple optimisation levels; generation of 80186/80286/8087 instructions; warning suppression; and multiple memory models. The Scotts Valley, California company claims that compiler optimisations include automatic register assignment and common sub-expression elimination. Turbo C implements the forthcoming ANSI C standard as far as it is defined, and delivers full support of Kernighan and Ritchie C. Special extensions for the Personal include the six memory models and extensions for mixed-language, mixed-model programming. The run operation within the integrated environment will recompile all necessary files, generate the executable code and run the program, then return back to the user interface. The editor window and the message window can be invoked within the editor; and the user can toggle between these windows. In the editor window, a full screen editor is provided with insert/overwrite, auto-indent, and block copy, move, read, write and delete along with other functions. In the message window, warnings and compiler error messages can be turned off selectively at different levels. Turbo C steps through multiple errors, and the interactive editor automatically positions the cursor in the source code at the point of error. Benchmarks quoted by Borland suggest that on a 6MHz AT, Turbo C is over four times as fast compiling, over three times as fast compiling and linking, and nearly twice as fast executing, as Microsoft’s C 4.0, while producing object code 7.7% more compact. Turbo C will cost $100.
