void use(char&);

void loop() {
    char storage[16] = {};
    for(char& c : storage) use(c);
}

----------------------------------------
define void @_Z4loopv() {
%entry:
  %storage = alloca i64 16, align 16, dead
  %0 = gep inbounds * %storage, 16 x i64 0, 1 x i64 0
  start_lifetime * %0
  memset * %0 align 16, i8 0, i64 16
  %add.ptr = gep inbounds * %storage, 16 x i64 0, 1 x i64 16
  br label %for.body

%for.body:
  %__begin1.09 = phi * [ %0, %entry ], [ %incdec.ptr, %for.body ]
  call void @_Z3useRc(nonnull dereferenceable(1) * %__begin1.09)
  %incdec.ptr = gep inbounds * %__begin1.09, 1 x i64 1
  %cmp = icmp eq * %incdec.ptr, %add.ptr
  br i1 %cmp, label %for.cond.cleanup, label %for.body

%for.cond.cleanup:
  free * %0 unconstrained
  ret void
}
=>
define void @_Z4loopv() {
%entry:
  %storage = alloca i64 16, align 16, dead
  %0 = gep inbounds * %storage, 16 x i64 0, 1 x i64 0
  start_lifetime * %0
  memset * %0 align 16, i8 0, i64 16
  %add.ptr = gep inbounds * %storage, 16 x i64 0, 1 x i64 16
  br label %for.body

%for.body:
  %__begin1.09 = phi * [ %0, %entry ], [ %incdec.ptr, %for.body ]
  call void @_Z3useRc(nonnull dereferenceable(1) * %__begin1.09)
  %incdec.ptr = gep inbounds * %__begin1.09, 1 x i64 1
  %cmp = icmp eq * %incdec.ptr, %add.ptr
  br i1 %cmp, label %for.cond.cleanup, label %for.body

%for.cond.cleanup:
  free * %0 unconstrained
  ret void
}
ERROR: Precondition is always false

Summary:
  0 correct transformations
  0 incorrect transformations
  1 Alive2 errors