reducing

Delta:

$ cat check-2.sh 
#!/bin/bash

ulimit -t 3; ~/work/llvm/build-release/bin/opt -S $1 | ~/work/llvm/build-release/bin/lli
if ! test "$?" = "0"; then
  exit 1
fi

ulimit -t 3; ~/work/llvm/build-release/bin/opt -sccp -S $1 | ~/work/llvm/build-release/bin/lli
if test "$?" = "0"; then
  exit 1
fi
exit 0

Bugpoint:
~/work/llvm/build-release/bin/bugpoint -compile-custom -compile-command=./check-bugpoint.sh -opt-command=/home/davide/work/llvm/build-release/bin/opt 2844.c

$ cat check-bugpoint.sh 
#!/bin/bash

ulimit -t 3; ~/work/llvm/build-release/bin/opt -S $1 | ~/work/llvm/build-release/bin/lli
res_old=$?

ulimit -t 3; ~/work/llvm/build-release/bin/opt -sccp -S $1 | ~/work/llvm/build-release/bin/lli
res_new=$?

[[ $res_old == 0 && $res_new != 0 ]] && exit 1
exit 0