From d9b091472f9afb216fe9f0c763053baf89390a6c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Magnus=20L=C3=A5ng?= <margnus1@telia.com>
Date: Fri, 10 Jun 2016 19:29:22 +0200
Subject: hipe_arm: Minimise CFG<->linear conversions

Now, there will only ever be a single Linear->CFG conversion, just after
lowering from RTL, and only ever a single CFG->Linear conversion, just
before the finalise pass. Both of these now happen in hipe_arm_main.
---
 lib/hipe/arm/hipe_arm_frame.erl | 97 ++++++++++++++++++-----------------------
 1 file changed, 43 insertions(+), 54 deletions(-)

(limited to 'lib/hipe/arm/hipe_arm_frame.erl')

diff --git a/lib/hipe/arm/hipe_arm_frame.erl b/lib/hipe/arm/hipe_arm_frame.erl
index e1e441a967..9a349b47d3 100644
--- a/lib/hipe/arm/hipe_arm_frame.erl
+++ b/lib/hipe/arm/hipe_arm_frame.erl
@@ -27,16 +27,14 @@
 
 -define(LIVENESS_ALL, hipe_arm_liveness_gpr). % since we have no FP yet
 
-frame(Defun) ->
-  Formals = fix_formals(hipe_arm:defun_formals(Defun)),
-  Temps0 = all_temps(hipe_arm:defun_code(Defun), Formals),
-  MinFrame = defun_minframe(Defun),
+frame(CFG) ->
+  Formals = fix_formals(hipe_arm_cfg:params(CFG)),
+  Temps0 = all_temps(CFG, Formals),
+  MinFrame = defun_minframe(CFG),
   Temps = ensure_minframe(MinFrame, Temps0),
-  ClobbersLR = clobbers_lr(hipe_arm:defun_code(Defun)),
-  CFG0 = hipe_arm_cfg:init(Defun),
-  Liveness = ?LIVENESS_ALL:analyse(CFG0),
-  CFG1 = do_body(CFG0, Liveness, Formals, Temps, ClobbersLR),
-  hipe_arm_cfg:linearise(CFG1).
+  ClobbersLR = clobbers_lr(CFG),
+  Liveness = ?LIVENESS_ALL:analyse(CFG),
+  do_body(CFG, Liveness, Formals, Temps, ClobbersLR).
 
 fix_formals(Formals) ->
   fix_formals(hipe_arm_registers:nr_args(), Formals).
@@ -51,32 +49,21 @@ do_body(CFG0, Liveness, Formals, Temps, ClobbersLR) ->
   do_prologue(CFG1, Context).
 
 do_blocks(CFG, Context) ->
-  Labels = hipe_arm_cfg:labels(CFG),
-  do_blocks(Labels, CFG, Context).
+  hipe_arm_cfg:map_bbs(fun(Lbl, BB) -> do_block(Lbl, BB, Context) end, CFG).
 
-do_blocks([Label|Labels], CFG, Context) ->
+do_block(Label, Block, Context) ->
   Liveness = context_liveness(Context),
   LiveOut = ?LIVENESS_ALL:liveout(Liveness, Label),
-  Block = hipe_arm_cfg:bb(CFG, Label),
   Code = hipe_bb:code(Block),
-  NewCode = do_block(Code, LiveOut, Context),
-  NewBlock = hipe_bb:code_update(Block, NewCode),
-  NewCFG = hipe_arm_cfg:bb_add(CFG, Label, NewBlock),
-  do_blocks(Labels, NewCFG, Context);
-do_blocks([], CFG, _) ->
-  CFG.
-
-do_block(Insns, LiveOut, Context) ->
-  do_block(Insns, LiveOut, Context, context_framesize(Context), []).
+  NewCode = do_block(Code, LiveOut, Context, context_framesize(Context), []),
+  hipe_bb:code_update(Block, NewCode).
 
 do_block([I|Insns], LiveOut, Context, FPoff0, RevCode) ->
   {NewIs, FPoff1} = do_insn(I, LiveOut, Context, FPoff0),
   do_block(Insns, LiveOut, Context, FPoff1, lists:reverse(NewIs, RevCode));
 do_block([], _, Context, FPoff, RevCode) ->
   FPoff0 = context_framesize(Context),
-  if FPoff =:= FPoff0 -> [];
-     true -> exit({?MODULE,do_block,FPoff})
-  end,
+  FPoff0 = FPoff,
   lists:reverse(RevCode, []).
 
 do_insn(I, LiveOut, Context, FPoff) ->
@@ -543,39 +530,46 @@ temp_is_pseudo(Temp) ->
 %%% Detect if a Defun's body clobbers LR.
 %%%
 
-clobbers_lr(Insns) ->
+clobbers_lr(CFG) ->
   LRreg = hipe_arm_registers:lr(),
   LRtagged = hipe_arm:mk_temp(LRreg, 'tagged'),
   LRuntagged = hipe_arm:mk_temp(LRreg, 'untagged'),
-  clobbers_lr(Insns, LRtagged, LRuntagged).
-
-clobbers_lr([I|Insns], LRtagged, LRuntagged) ->
-  Defs = hipe_arm_defuse:insn_def_gpr(I),
-  case lists:member(LRtagged, Defs) of
-    true -> true;
-    false ->
-      case lists:member(LRuntagged, Defs) of
-	true -> true;
-	false -> clobbers_lr(Insns, LRtagged, LRuntagged)
-      end
-  end;
-clobbers_lr([], _LRtagged, _LRuntagged) -> false.
+  any_insn(fun(I) ->
+	       Defs = hipe_arm_defuse:insn_def_gpr(I),
+	       lists:member(LRtagged, Defs)
+		 orelse lists:member(LRuntagged, Defs)
+	   end, CFG).
+
+any_insn(Pred, CFG) ->
+  %% Abuse fold to do an efficient "any"-operation using nonlocal control flow
+  FoundSatisfying = make_ref(),
+  try fold_insns(fun (I, _) ->
+		     case Pred(I) of
+		       true -> throw(FoundSatisfying);
+		       false -> false
+		     end
+		 end, false, CFG)
+  of _ -> false
+  catch FoundSatisfying -> true
+  end.
 
 %%%
 %%% Build the set of all temps used in a Defun's body.
 %%%
 
-all_temps(Code, Formals) ->
-  S0 = find_temps(Code, tset_empty()),
+all_temps(CFG, Formals) ->
+  S0 = fold_insns(fun find_temps/2, tset_empty(), CFG),
   S1 = tset_del_list(S0, Formals),
   tset_filter(S1, fun(T) -> temp_is_pseudo(T) end).
 
-find_temps([I|Insns], S0) ->
+find_temps(I, S0) ->
   S1 = tset_add_list(S0, hipe_arm_defuse:insn_def_all(I)),
-  S2 = tset_add_list(S1, hipe_arm_defuse:insn_use_all(I)),
-  find_temps(Insns, S2);
-find_temps([], S) ->
-  S.
+  tset_add_list(S1, hipe_arm_defuse:insn_use_all(I)).
+
+fold_insns(Fun, InitAcc, CFG) ->
+  hipe_arm_cfg:fold_bbs(
+    fun(_, BB, Acc0) -> lists:foldl(Fun, Acc0, hipe_bb:code(BB)) end,
+    InitAcc, CFG).
 
 tset_empty() ->
   gb_sets:new().
@@ -604,16 +598,11 @@ tset_to_list(S) ->
 %%% in the middle of a tailcall.
 %%%
 
-defun_minframe(Defun) ->
-  MaxTailArity = body_mta(hipe_arm:defun_code(Defun), 0),
-  MyArity = length(fix_formals(hipe_arm:defun_formals(Defun))),
+defun_minframe(CFG) ->
+  MaxTailArity = fold_insns(fun insn_mta/2, 0, CFG),
+  MyArity = length(fix_formals(hipe_arm_cfg:params(CFG))),
   erlang:max(MaxTailArity - MyArity, 0).
 
-body_mta([I|Code], MTA) ->
-  body_mta(Code, insn_mta(I, MTA));
-body_mta([], MTA) ->
-  MTA.
-
 insn_mta(I, MTA) ->
   case I of
     #pseudo_tailcall{arity=Arity} ->
-- 
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