diff options
Diffstat (limited to 'lib/hipe/icode/hipe_icode.erl')
| -rw-r--r-- | lib/hipe/icode/hipe_icode.erl | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/hipe/icode/hipe_icode.erl b/lib/hipe/icode/hipe_icode.erl index 78508dff22..d2d08e0253 100644 --- a/lib/hipe/icode/hipe_icode.erl +++ b/lib/hipe/icode/hipe_icode.erl @@ -438,6 +438,7 @@ if_true_label/1, if_false_label/1, if_args/1, + if_args_update/2, if_pred/1, %% is_if/1, @@ -594,6 +595,7 @@ uses/1, defines/1, is_safe/1, + reduce_unused/1, strip_comments/1, subst/2, subst_uses/2, @@ -713,6 +715,9 @@ if_op_update(IF, NewOp) -> IF#icode_if{op=NewOp}. -spec if_args(#icode_if{}) -> [icode_term_arg()]. if_args(#icode_if{args=Args}) -> Args. +-spec if_args_update(#icode_if{}, [icode_term_arg()]) -> #icode_if{}. +if_args_update(IF, Args) -> IF#icode_if{args=Args}. + -spec if_true_label(#icode_if{}) -> icode_lbl(). if_true_label(#icode_if{true_label=TrueLbl}) -> TrueLbl. @@ -1765,6 +1770,18 @@ is_safe(Instr) -> #icode_end_try{} -> false end. +%% @doc Produces a simplified instruction sequence that is equivalent to [Instr] +%% under the assumption that all results of Instr are unused, or 'false' if +%% there is no such sequence (other than [Instr] itself). + +-spec reduce_unused(icode_instr()) -> false | [icode_instr()]. + +reduce_unused(Instr) -> + case is_safe(Instr) of + true -> []; + false -> false + end. + %%----------------------------------------------------------------------- -spec highest_var(icode_instrs()) -> non_neg_integer(). |