------- Additional Comments From Thomas dot Koenig at online dot de 2004-12-12
10:42 -------
(In reply to comment #2)
> Speculations I'd put money on if the bookies would accept it:
> 1) You can show this same problem with C/C++ if you have enough cases.
Yes.
$ time ./multi-case-c 150000 > multi-case.c
$ gcc multi-case.c
cc1: out of memory allocating 2815331376 bytes after a total of 10571776 bytes
$ gcc -v
Reading specs from /home/ig25/lib/gcc/i686-pc-linux-gnu/4.0.0/specs
Configured with: ../gcc/configure --prefix=/home/ig25
--enable-languages=c,c++,f95
Thread model: posix
gcc version 4.0.0 20041208 (experimental)
$ cat multi-case-c
#! /usr/bin/perl
$last = shift;
for ($i=1; $i<=$last; $i++) {
push(@lines, sprintf(" case %d:\n j = %d;\n break;\n", $i,
$last-$i));
}
for ($i=0; $i<=$last; $i++) {
$j = int(rand($last));
$temp = $lines[$i];
$lines[$i] = $lines[$j];
$lines[$j] = $temp;
}
print <<EOF;
#include <stdio.h>
int main()
{
int i,j;
scanf("%d",&i);
switch(i) {
EOF
print @lines;
print <<EOF;
}
printf("%d\\n",i);
return 0;
}
EOF
$ ./multi-case-c 4
#include <stdio.h>
int main()
{
int i,j;
scanf("%d",&i);
switch(i) {
case 2:
j = 2;
break;
case 4:
j = 0;
break;
case 3:
j = 1;
break;
case 1:
j = 3;
break;
}
printf("%d\n",i);
return 0;
This isn't a regression, gcc 3.3 had the same problem:
$ /usr/bin/gcc multi-case.c
cc1: out of memory allocating 2815312608 bytes after a total of 18419712 bytes
$ /usr/bin/gcc -v
Reading specs from /usr/lib/gcc-lib/i486-linux/3.3.5/specs
Configured with: ../src/configure -v
--enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr
--mandir=/usr/share/man
--infodir=/usr/share/info--with-gxx-include-dir=/usr/include/c++/3.3
--enable-shared --with-system-zlib --enable-nls --without-included-gettext
--enable-__cxa_atexit --enable-clocale=gnu --enable-debug --enable-java-gc=boehm
--enable-java-awt=xlib --enable-objc-gci486-linux
Thread model: posix
gcc version 3.3.5 (Debian 1:3.3.5-3)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18938
