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author | hobbs <hobbs> | 2010-11-30 18:16:01 (GMT) |
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committer | hobbs <hobbs> | 2010-11-30 18:16:01 (GMT) |
commit | 881d5025bf794494317b6490233cde4438ed8d5e (patch) | |
tree | 1813237c573abb3ecbb46ec846d9b34db02dac3a /generic/tclUtil.c | |
parent | f2b2931008f39ae6f8fd977c0315178099fa9d8b (diff) | |
download | tcl-881d5025bf794494317b6490233cde4438ed8d5e.zip tcl-881d5025bf794494317b6490233cde4438ed8d5e.tar.gz tcl-881d5025bf794494317b6490233cde4438ed8d5e.tar.bz2 |
* generic/tclInt.decls, generic/tclInt.h, generic/tclIntDecls.h:
* generic/tclStubInit.c: TclFormatInt restored at slot 24
* generic/tclUtil.c (TclFormatInt): restore TclFormatInt func from
2005-07-05 macro-ization. Benchmarks indicate it is faster, as a
key int->string routine (e.g. int-indexed arrays).
Diffstat (limited to 'generic/tclUtil.c')
-rw-r--r-- | generic/tclUtil.c | 88 |
1 files changed, 87 insertions, 1 deletions
diff --git a/generic/tclUtil.c b/generic/tclUtil.c index 64d36f4..e4083fc 100644 --- a/generic/tclUtil.c +++ b/generic/tclUtil.c @@ -11,7 +11,7 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclUtil.c,v 1.97.2.6 2010/08/10 20:48:21 hobbs Exp $ + * RCS: @(#) $Id: tclUtil.c,v 1.97.2.7 2010/11/30 18:16:02 hobbs Exp $ */ #include "tclInt.h" @@ -2522,6 +2522,92 @@ TclNeedSpace( /* *---------------------------------------------------------------------- * + * TclFormatInt -- + * + * This procedure formats an integer into a sequence of decimal digit + * characters in a buffer. If the integer is negative, a minus sign is + * inserted at the start of the buffer. A null character is inserted at + * the end of the formatted characters. It is the caller's + * responsibility to ensure that enough storage is available. This + * procedure has the effect of sprintf(buffer, "%ld", n) but is faster + * as proven in benchmarks. This is key to UpdateStringOfInt, which + * is a common path for a lot of code (e.g. int-indexed arrays). + * + * Results: + * An integer representing the number of characters formatted, not + * including the terminating \0. + * + * Side effects: + * The formatted characters are written into the storage pointer to + * by the "buffer" argument. + * + *---------------------------------------------------------------------- + */ + +int +TclFormatInt(buffer, n) + char *buffer; /* Points to the storage into which the + * formatted characters are written. */ + long n; /* The integer to format. */ +{ + long intVal; + int i; + int numFormatted, j; + char *digits = "0123456789"; + + /* + * Check first whether "n" is zero. + */ + + if (n == 0) { + buffer[0] = '0'; + buffer[1] = 0; + return 1; + } + + /* + * Check whether "n" is the maximum negative value. This is + * -2^(m-1) for an m-bit word, and has no positive equivalent; + * negating it produces the same value. + */ + + if (n == -n) { + return sprintf(buffer, "%ld", n); + } + + /* + * Generate the characters of the result backwards in the buffer. + */ + + intVal = (n < 0? -n : n); + i = 0; + buffer[0] = '\0'; + do { + i++; + buffer[i] = digits[intVal % 10]; + intVal = intVal/10; + } while (intVal > 0); + if (n < 0) { + i++; + buffer[i] = '-'; + } + numFormatted = i; + + /* + * Now reverse the characters. + */ + + for (j = 0; j < i; j++, i--) { + char tmp = buffer[i]; + buffer[i] = buffer[j]; + buffer[j] = tmp; + } + return numFormatted; +} + +/* + *---------------------------------------------------------------------- + * * TclGetIntForIndex -- * * This function returns an integer corresponding to the list index held |