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-rw-r--r--lib/hipe/flow/cfg.inc50
1 files changed, 45 insertions, 5 deletions
diff --git a/lib/hipe/flow/cfg.inc b/lib/hipe/flow/cfg.inc
index a18bfbc526..97f6064822 100644
--- a/lib/hipe/flow/cfg.inc
+++ b/lib/hipe/flow/cfg.inc
@@ -32,6 +32,8 @@
%% bb(CFG, Label) - returns the basic block named 'Label' from the CFG.
%% bb_add(CFG, Label, NewBB) - makes NewBB the basic block associated
%% with Label.
+%% map_bbs(Fun, CFG) - map over all code without changing control flow.
+%% fold_bbs(Fun, Acc, CFG) - fold over the basic blocks in a CFG.
%% succ(Map, Label) - returns a list of successors of basic block 'Label'.
%% pred(Map, Label) - returns the predecessors of basic block 'Label'.
%% fallthrough(CFG, Label) - returns fall-through successor of basic
@@ -307,11 +309,7 @@ redirect_phis([I|Rest], OldPred, NewPred, Acc) ->
%% @doc Adds a new basic block to a CFG (or updates an existing block).
bb_add(CFG, Label, NewBB) ->
%% Asserting that the NewBB is a legal basic block
- Last = hipe_bb:last(NewBB),
- case is_branch(Last) of
- true -> ok;
- false -> throw({?MODULE, {"Basic block ends without branch", Last}})
- end,
+ Last = assert_bb(NewBB),
%% The order of the elements from branch_successors/1 is
%% significant. It determines the basic block order when the CFG is
%% converted to linear form. That order may have been tuned for
@@ -339,6 +337,48 @@ bb_add(CFG, Label, NewBB) ->
HT2, OldSucc -- Succ),
CFG#cfg{table = HT3}.
+-ifdef(MAP_FOLD_NEEDED).
+-spec map_bbs(fun((cfg_lbl(), hipe_bb:bb()) -> hipe_bb:bb()), cfg()) -> cfg().
+%% @doc Map over the code in a CFG without changing any control flow.
+map_bbs(Fun, CFG = #cfg{table=HT0}) ->
+ HT = gb_trees:map(
+ fun(Lbl, {OldBB, OldSucc, OldPred}) ->
+ NewBB = Fun(Lbl, OldBB),
+ %% Assert preconditions
+ NewLast = assert_bb(NewBB),
+ OldSucc = remove_duplicates(branch_successors(NewLast)),
+ {NewBB, OldSucc, OldPred}
+ end, HT0),
+ CFG#cfg{table=HT}.
+
+-spec fold_bbs(fun((cfg_lbl(), hipe_bb:bb(), Acc) -> Acc), Acc, cfg()) -> Acc.
+%% @doc Fold over the basic blocks in a CFG in unspecified order.
+fold_bbs(Fun, InitAcc, #cfg{table=HT}) ->
+ gb_trees_fold(fun(Lbl, {BB, _, _}, Acc) -> Fun(Lbl, BB, Acc) end,
+ InitAcc, HT).
+
+gb_trees_fold(Fun, InitAcc, Tree) ->
+ gb_trees_fold_1(Fun, InitAcc, gb_trees:iterator(Tree)).
+
+gb_trees_fold_1(Fun, InitAcc, Iter0) ->
+ case gb_trees:next(Iter0) of
+ none -> InitAcc;
+ {Key, Value, Iter} ->
+ gb_trees_fold_1(Fun, Fun(Key, Value, InitAcc), Iter)
+ end.
+-endif. % MAP_FOLD_NEEDED
+
+assert_bb(BB) ->
+ assert_bb_is(hipe_bb:code(BB)).
+
+assert_bb_is([Last]) ->
+ true = is_branch(Last),
+ Last;
+assert_bb_is([I|Is]) ->
+ false = is_branch(I),
+ false = is_label(I),
+ assert_bb_is(Is).
+
remove_pred(HT, FromL, PredL) ->
case gb_trees:lookup(FromL, HT) of
{value, {Block, Succ, Preds}} ->