diff options
Diffstat (limited to 'lib/hipe/rtl/hipe_rtl_lcm.erl')
| -rw-r--r-- | lib/hipe/rtl/hipe_rtl_lcm.erl | 110 |
1 files changed, 59 insertions, 51 deletions
diff --git a/lib/hipe/rtl/hipe_rtl_lcm.erl b/lib/hipe/rtl/hipe_rtl_lcm.erl index 9dcdd05fb1..2c8cc80e56 100644 --- a/lib/hipe/rtl/hipe_rtl_lcm.erl +++ b/lib/hipe/rtl/hipe_rtl_lcm.erl @@ -182,42 +182,41 @@ delete_exprs(Code, _, _, []) -> Code; delete_exprs(Code, ExprMap, IdMap, [ExprId|Exprs]) -> Expr = expr_id_map_get_expr(IdMap, ExprId), - %% Perform a foldl that goes through the code and deletes all - %% occurences of the expression. - NewCode = - lists:reverse - (lists:foldl(fun(CodeExpr, Acc) -> - case is_expr(CodeExpr) of - true -> - case expr_clear_dst(CodeExpr) =:= Expr of - true -> - pp_debug(" Deleting: ", []), - pp_debug_instr(CodeExpr), - %% Lookup expression entry. - Defines = - case expr_map_lookup(ExprMap, Expr) of - {value, {_, _, Defs}} -> - Defs; - none -> - exit({?MODULE, expr_map_lookup, - "expression missing"}) - end, - MoveCode = - mk_expr_move_instr(hipe_rtl:defines(CodeExpr), - Defines), - pp_debug(" Replacing with: ", []), - pp_debug_instr(MoveCode), - [MoveCode|Acc]; - false -> - [CodeExpr|Acc] - end; - false -> - [CodeExpr|Acc] - end - end, - [], Code)), + %% Lookup expression entry. + {value, {_, _, Defines}} = expr_map_lookup(ExprMap, Expr), + %% Go through the code and deletes all occurences of the expression. + NewCode = delete_expr(Code, Expr, Defines, []), delete_exprs(NewCode, ExprMap, IdMap, Exprs). +delete_expr([], _Expr, _Defines, Acc) -> lists:reverse(Acc); +delete_expr([CodeExpr|Code], Expr, Defines, Acc) -> + case exp_kill_expr(CodeExpr, [Expr]) of + [] -> % Expr was killed; deleting stops here + pp_debug(" Stopping before: ", []), + pp_debug_instr(CodeExpr), + lists:reverse(Acc, [CodeExpr|Code]); + [Expr] -> + NewCodeExpr = + case is_expr(CodeExpr) of + true -> + case expr_clear_dst(CodeExpr) =:= Expr of + true -> + pp_debug(" Deleting: ", []), + pp_debug_instr(CodeExpr), + MoveCode = mk_expr_move_instr(hipe_rtl:defines(CodeExpr), + Defines), + pp_debug(" Replacing with: ", []), + pp_debug_instr(MoveCode), + MoveCode; + false -> + CodeExpr + end; + false -> + CodeExpr + end, + delete_expr(Code, Expr, Defines, [NewCodeExpr|Acc]) + end. + %%============================================================================= %% Goes through the given list of expressions and inserts them at %% appropriate places in the code. @@ -226,13 +225,12 @@ insert_exprs(CFG, _, _, _, _, BetweenMap, []) -> insert_exprs(CFG, Pred, Succ, ExprMap, IdMap, BetweenMap, [ExprId|Exprs]) -> Expr = expr_id_map_get_expr(IdMap, ExprId), Instr = expr_map_get_instr(ExprMap, Expr), - case hipe_rtl_cfg:succ(CFG, Pred) of - [_] -> + case try_insert_expr_last(CFG, Pred, Instr) of + {ok, NewCFG} -> pp_debug(" Inserted last: ", []), pp_debug_instr(Instr), - NewCFG = insert_expr_last(CFG, Pred, Instr), insert_exprs(NewCFG, Pred, Succ, ExprMap, IdMap, BetweenMap, Exprs); - _ -> + not_safe -> case hipe_rtl_cfg:pred(CFG, Succ) of [_] -> pp_debug(" Inserted first: ", []), @@ -252,25 +250,34 @@ insert_exprs(CFG, Pred, Succ, ExprMap, IdMap, BetweenMap, [ExprId|Exprs]) -> %% Recursively goes through the code in a block and returns a new block %% with the new code inserted second to last (assuming the last expression %% is a branch operation). -insert_expr_last(CFG0, Label, Instr) -> - Code0 = hipe_bb:code(hipe_rtl_cfg:bb(CFG0, Label)), - %% FIXME: Use hipe_bb:butlast() instead? - Code1 = insert_expr_last_work(Label, Instr, Code0), - hipe_rtl_cfg:bb_add(CFG0, Label, hipe_bb:mk_bb(Code1)). +try_insert_expr_last(CFG0, Label, Instr) -> + case hipe_rtl_cfg:succ(CFG0, Label) of + [_] -> + Code0 = hipe_bb:code(hipe_rtl_cfg:bb(CFG0, Label)), + case insert_expr_last_work(Instr, Code0) of + not_safe -> not_safe; + Code1 -> + {ok, hipe_rtl_cfg:bb_add(CFG0, Label, hipe_bb:mk_bb(Code1))} + end; + _ -> not_safe + end. %%============================================================================= %% Recursively goes through the code in a block and returns a new block %% with the new code inserted second to last (assuming the last expression %% is a branch operation). -insert_expr_last_work(_, Instr, []) -> - %% This case should not happen since this means that block was completely - %% empty when the function was called. For compatibility we insert it last. - [Instr]; -insert_expr_last_work(_, Instr, [Code1]) -> +insert_expr_last_work(_Instr, [#call{}]) -> + %% Call instructions clobber all expressions; we must not insert the + %% expression before it + not_safe; +insert_expr_last_work(Instr, [Code1]) -> %% We insert the code next to last. [Instr, Code1]; -insert_expr_last_work(Label, Instr, [Code|Codes]) -> - [Code|insert_expr_last_work(Label, Instr, Codes)]. +insert_expr_last_work(Instr, [Code|Codes]) -> + case insert_expr_last_work(Instr, Codes) of + not_safe -> not_safe; + NewCodes -> [Code|NewCodes] + end. %%============================================================================= %% Inserts expression first in the block for the given label. @@ -305,7 +312,8 @@ insert_expr_between(CFG0, BetweenMap, Pred, Succ, Instr) -> {value, Label} -> pp_debug(" Using existing new bb for edge (~w,~w) with label ~w~n", [Pred, Succ, Label]), - {insert_expr_last(CFG0, Label, Instr), BetweenMap} + {ok, NewCfg} = try_insert_expr_last(CFG0, Label, Instr), + {NewCfg, BetweenMap} end. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |