[Bug middle-end/40259] New: Unintended code in find_givs_in_stmt_scev (gcc/tree-ssa-loop-ivopts.c)?

[sergei_lus at yahoo dot com]

The code for  find_givs_in_stmt_scev (gcc/tree-ssa-loop-ivopts.c) used to be
(in 4.3.2) this:

  lhs = GIMPLE_STMT_OPERAND (stmt, 0);
  if (TREE_CODE (lhs) != SSA_NAME)
    return false;

  if (!simple_iv (loop, stmt, GIMPLE_STMT_OPERAND (stmt, 1), iv, true))
    return false;

...which has changed in 4.4.0 (or on trunk - 147831) to this: 

    lhs = gimple_assign_lhs (stmt);
  if (TREE_CODE (lhs) != SSA_NAME)
    return false;

  if (!simple_iv (loop, loop_containing_stmt (stmt), lhs, iv, true))
    return false;

The gimple_assign_lhs is not the same as GIMPLE_STMT_OPERAND (stmt, 1). 
Was it intended to be something like this:

  if (!simple_iv (loop, loop_containing_stmt (stmt), gimple_assign_rhs_to_tree
(stmt), iv, true))
    return false;


-- 
           Summary: Unintended code in find_givs_in_stmt_scev (gcc/tree-ssa-
                    loop-ivopts.c)?
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sergei_lus at yahoo dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40259