llvm-project/llvm/test/FrontendC/2008-01-07-UnusualIntSize.c

// RUN: %llvmgcc %s -S -o - -O | grep i33
// PR1721

struct s {
  unsigned long long u33: 33;
} a, b;

// This should turn into a real 33-bit add, not a 64-bit add.
_Bool test(void) {
  return a.u33 + b.u33 != 0;
}