Libris Britannia 4/science library(b).zip/science library(b)/PROGRAMM/CC_C/1199.ZIP/HISTORY

Text File | 1988-08-06 | 8KB | 118 lines

Small-C Revision History

 -- included in version 2.2

 76 Modified _read() in CSYSLIB.C to do console input through _getkey()
    for consistent handling of special key values per the MS-DOS addendum
    to the Small-C Handbook.
 77 Modified fgetc() in FGETC.C to look for an ungotten character and
    return it without cooking it (since it cooked on the original get).
    This fixed an apparent problem in scanf() and fscanf() in which
    they appear to miss input characters.
 78 Revised out_code() and do more optimizing.  Let p-code subscript code[],
    (an array of pointers to output assembly code strings) instead of using
    a monstrous switch statement.
 79 Always compile features that are now considered standard.
 80 Properly calculate swend in main() to use all of the switch table.
 81 Dropped unnecessary variable func1.
 82 Changed if(match(...)); to match(...); statements.
 83 Dropped unnecessary while loop in declloc().
 84 Simplified treatment of argument "dim" in initials().
 85 Dropped outside() because it is redundant with code in compound().
 86 Revised the point at which lval2[] is declared in plnge(), and hier14()
    to greatly reduce the amount of stack space used during expression
    analysis by allocating lval[] arrays only when actually needed.
 87 Simplified logic in newfunc(), doif(), dodo(), preprocess(), skip(),
    plnge(), expression(), hier14(), primary(), pstr(), white().
 88 Modified primary() to add an undeclared function to the symbol table only
    if the name is not already in the table.  This improves run time by
    saving a table lookup on most function references.
 89 Reorganized source code into four files (CC1.C, CC2.C, CC3.C, CC4.C),
    regrouped functions into more logical units, and renamed some functions
    (addmac->dodefine, newfunc->dofunction, rvalue->fetch, pstr->chrcon,
    qstr->string, needtoken->need, col->colon, ol->outline, junk->skip).
 90 Improved output efficiency by deleting cout(), sout(), and xout().
    It now checks for an output error only at the end of a line.
 91 Dropped assignment statements in main() that set globals to zero.
 92 Revised ispunct() to exclude white space from the 'true' condition.
 93 Combined all of the is...() character classification functions into a
    single module of short, fast functions that subscript into an array
    for the answer.  This approach is three times faster.
 94 Per Kiyoshi Akima, eliminated LINK module from library.  Now, trailer()
    declares _MAIN to be external if main() is declared in the module being
    compiled; this forces CSYSLIB to load when linking.  By not declaring it
    external in other modules, a "multiply defined" error is eliminated when
    compiling CSYSLIB which contains _MAIN.  However, since .OBJ modules
    which were compiled with earlier versions of Small-C contain references to
    __LINK, it is declared as a dummy entry point in CALL.ASM to avoid
    "unresolved reference" errors at link time.
 95 Per Kiyoshi Akima, installed additional code optimizing.
 96 Dropped setops() in favor of initializing the op[] and op2[] arrays.
    This can be done since these arrays now contain p-codes rather than
    function addresses.
 97 Yet another rewrite of the the optimizer.  It's now much smaller, each
    optimization is cheaper, the logic is clearer and more bullet proof.
    And, yet more optimizations.  EXE sizes are down by 10% and execution times
    are down by as much as 25%.
 98 Renamed CC.DEF to CC.H and CLIB.DEF to CLIB.H.
 99 Corrected unlink() to return ERR on failure instead of EOF.
100 Revision 76 slowed down the reading of files considerably by introducing
    an additional call to iscons() for every character read.  It was discovered
    that the DOS interrupt in this function is very very slow.  So, iscons()
    was revised to call DOS only the first time for a file, and then test
    the rememberred answer thereafter.  This required changes to CSYSLIB.C
    also.  The effect was a DOUBLING OF I/O SPEED DURING READS, compared to
    revision level 75 -- BEFORE the slowdown was introduced.  This shows that
    the existing calls to iscons() in fgetc() and fgets() have been a major
    bottleneck all along.
101 Added the "unsigned" integer and character data types.  These result in
    unsigned <, <=, >, >=, *, /, % operations and yield unsigned results.
102 Revised the handling of numeric constants to recognize values from
    32768 to 65535 as unsigned.  These, likewise, produce unsigned operations
    and yield unsigned results.
103 Cleaned up the handling of non-definitional function declarations.  The
    syntax (*func)(), which specifies a pointer to a function, is now accepted
    only for function arguments.  Previously, it was accepted at the global and
    local levels, but not interpreted as a pointer.
104 Reject instances of declarations, such as *func(), which have multiple
    modifiers.  Previously, the right most modifier prevailed.  But it is
    better to reject something than to interpret in differently than it is
    written.
105 Accept "void" before function header as comment.
106 Corrected an error in the expression analyzer which causes pointer offsets
    to be lost when subscripting is applied; e.g., (ptr+5)[x] would lose the
    offset 5.
107 Revised the implementation of the sizeof() operator so it works correctly.
    Although undocumented, this was in the original MS-DOS compiler.
108 Always pass an argument count to functions, even if NOCCARGC is defined.
    This is not very costly on 8086 family CPUs and it eliminates a lot of
    headaches when you call printf() but forget that NOCCARGC is defined.
109 Small-C programs now abort with a return code of 1 for memory overflows
    and 2 for operator interruptions (control-C).
110 Revised strlen() to use the 8086 "REPNE SCASB" prefix/instruction for
    the fastest possible operation.  Sped it up over 500%.
111 Any redirection of stdout overrides the assumed output of the compiler,
    not just redirections to disk files.
112 Revised hier2() (now called level2()), which processes the ?: operator,
    so that it groups properly from right to left and yields meaningful
    attributes for further expression analysis.  This involved imposing
    consistency restrictions on the second and third expressions.
113 Revised dogoto(), dolabel(), and addlabel() to catch duplicate label
    definitions.
114 Revised outname() to write names to the output file without forcing them to
    uppercase.  Except for this function, the compiler was already case
    sensitive.  Also recompiled and assembled the library with lowercase names.
115 Modified the p-code translation strings containing "CALL xxx", where xxx
    is a CALL module entry point, so that xxx is in lower case.  This
    eliminates errors when case sensitivity is specified to the assembler and
    the linker.
116 Made minor revisions to allow command-line switches to be introduced by
    slashes (/) as well as hyphens (-).  This is consistant with the Small
    Assembler which accommodates slashes for consistency with the PC/MS-DOS
    linker which it employs.
117 Revised optimization cases 31 thru 33 to prevent generating corrupt code
    for statements like ++x[4]; where x[] is local.  Previously this statement
    would update the wrong memory location.  Deleted cases 31 and 32, and
    changed case 33 to do less optimizing.  Renumbered cases 33 thru 49 as
    31 thru 47.