Re: alloca (was: Postgres Speed or lack thereof) - Mailing list pgsql-hackers

The Hermit Hacker wrote:
> Make you a deal...
>
> You build the code such that "#ifdef HAVE_ALLOCA" is true, so that those
> platforms that either don't support it, or have broken suport for it,
> aren't affect, and you are most welcome to work on it...

Yeah right, I should keep my mouth shut. :-)

It is a big job, starting getting with getting profiling working on
my box, analyzing lots of code and then come up with some optimations.

We can start with the patch below to detect alloca() in autoconf.

    best regards,
--
-----------------
Göran Thyni
This is Penguin Country. On a quiet night you can hear Windows NT
reboot!diff -rc pgsql-orig/src/configure.in pgsql/src/configure.in
*** pgsql-orig/src/configure.in    Mon Jan 18 07:01:04 1999
--- pgsql/src/configure.in    Tue Jan 26 15:03:12 1999
***************
*** 692,697 ****
--- 692,698 ----
  AC_FUNC_MEMCMP
  AC_TYPE_SIGNAL
  AC_FUNC_VPRINTF
+ AC_FUNC_ALLOCA
  AC_CHECK_FUNCS(tzset memmove sigsetjmp kill sysconf fpclass)
  AC_CHECK_FUNCS(fp_class fp_class_d class)
  AC_CHECK_FUNCS(sigprocmask waitpid setsid fcvt)
diff -rc pgsql-orig/src/include/config.h.in pgsql/src/include/config.h.in
*** pgsql-orig/src/include/config.h.in    Mon Jan 18 07:02:26 1999
--- pgsql/src/include/config.h.in    Tue Jan 26 15:05:37 1999
***************
*** 115,120 ****
--- 115,123 ----
  # define gettimeofday(a,b) gettimeofday(a)
  #endif

+ /* Set to 1 if you have alloca() */
+ #undef HAVE_ALLOCA
+
  /* Set to 1 if you have snprintf() */
  #undef HAVE_SNPRINTF