Bug#376213: [amd64] : compiler produces wrong code for <<

[Vincent Fourmond <vincent.fourmond@9online.fr>]

Package: gcc-4.1
Version: 4.1.1-5
Severity: important
Justification: causes FTBS for at least one package (fftw)

  Hello !

  I simply compile and run the program attached on my amd64 box, and I get the following results:

iteration 0,  iters = 1
iteration 1,  iters = 2
iteration 2,  iters = 4
iteration 3,  iters = 8
iteration 4,  iters = 16
iteration 5,  iters = 32
iteration 6,  iters = 64
iteration 7,  iters = 128
iteration 8,  iters = 256
iteration 9,  iters = 512
iteration 10,  iters = 1024
iteration 11,  iters = 2048
iteration 12,  iters = 4096
iteration 13,  iters = 8192
iteration 14,  iters = 16384
iteration 15,  iters = 32768
iteration 16,  iters = 65536
iteration 17,  iters = 131072
iteration 18,  iters = 262144
iteration 19,  iters = 524288
iteration 20,  iters = 1048576
iteration 21,  iters = 2097152
iteration 22,  iters = 4194304
iteration 23,  iters = 8388608
iteration 24,  iters = 16777216
iteration 25,  iters = 33554432
iteration 26,  iters = 67108864
iteration 27,  iters = 134217728
iteration 28,  iters = 268435456
iteration 29,  iters = 536870912
iteration 30,  iters = 1073741824
iteration 31,  iters = 18446744071562067968

  There definitely *is* a problem in the last iteration. I wonder if it is a compiler bug or a 
processor bug -- I can't speak assembler anymore.

  Regards,

	Vincent Fourmond

-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.16
Locale: LANG=fr_FR, LC_CTYPE=fr_FR (charmap=ISO-8859-1) (ignored: LC_ALL set to en_GB)

Versions of packages gcc-4.1 depends on:
ii  binutils                      2.17-1     The GNU assembler, linker and bina
ii  cpp-4.1                       4.1.1-5    The GNU C preprocessor
ii  gcc-4.1-base                  4.1.1-5    The GNU Compiler Collection (base 
ii  libc6                         2.3.6-15   GNU C Library: Shared libraries
ii  libgcc1                       1:4.1.1-5  GCC support library

Versions of packages gcc-4.1 recommends:
ii  libc6-dev                     2.3.6-15   GNU C Library: Development Librari
ii  libmudflap0-dev               4.1.1-5    GCC mudflap support libraries (dev
ii  libssp0-dev                   4.1.1-5    GCC stack smashing protection libr

-- no debconf information

#include <stdio.h>

int main()
{
  unsigned long iters;
  int i;
  for (i = 0; i < 32; i++) {
    iters = 1 << (unsigned long) i; 
    printf("iteration %d,  iters = %lu\n", i, iters);
  }
}