#412 Small code optimisation....

[Anonymous]

In a number of cases in the core there are places where
multiple temporary buffers are separately ckalloc'd,
used, then separately ckfree'd. These could be rolled
into a single larger buffers which are then subdivided.
Not a great win, but it is faster.

eg. tclCmdAH.c

1705d1704
< char *allocbuf = NULL;
1740,1747c1739,1743
< const size_t sz1 = numLists * sizeof(int);
< const size_t sz2 = numLists * sizeof(Tcl_Obj **);
< allocbuf = (char *)ckalloc(3*sz1 + 2*sz2);
< index = (int *) allocbuf;
< varcList = (int *) ((char *)allocbuf + sz1);
< varvList = (Tcl_Obj **) ((char *)varcList + sz1);
< argcList = (int *) ((char *)varvList + sz2);
< argvList = (Tcl_Obj **) ((char *)argcList + sz1);
---
> index = (int *) ckalloc(numLists * sizeof(int));
> varcList = (int *) ckalloc(numLists * sizeof(int));
> varvList = (Tcl_Obj ***) ckalloc(numLists * sizeof
(Tcl_Obj **));
> argcList = (int *) ckalloc(numLists * sizeof(int));
> argvList = (Tcl_Obj ***) ckalloc(numLists * sizeof
(Tcl_Obj **));
1869c1865,1869
< ckfree((char *) allocbuf);
---
> ckfree((char *) index);
> ckfree((char *) varcList);
> ckfree((char *) argcList);
> ckfree((char *) varvList);
> ckfree((char *) argvList);

Admittedly this is not a common code path.

A similar change can be used in:

a) tclCmdMZ.c at lines ~1922 (string map) to reduce 2
or 3 ckalloc's down to 1.

b) tclCompCmds.c:
line ~687 for var[cv]list

c) tclCompCmds.c
line ~2933 for fixupArray and fixupTargetArray

Would save a few cycles.

[miguel sofer]

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Just remarking that (in 8.5) memory allocations that have
the lifetime of a command can (and should?) use
TclStackAlloc / TclStackFree. These allocate memory from
Tcl's execution stack.

[Donal K. Fellows]

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Feels like a low priority fix to me; assigning to someone
who cares more about doing minor opts than I do.

[Nobody/Anonymous]

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"/software/packages"=pkg_repl("perl-DBD-Pg","1.31-6","i386");