hipe: Add pseudo_spill_f?move instructions

These pseudo instructions are added to all backends and allow spill slot
to spill slot move coalescing in a clean way.

They have regular move semantics, but contain an additional scratch
register to be used if both source and destination are spilled, and can
not be move coalesced.

Additionally, a register allocator callback
Target:is_spill_move(Instr, Context) is added which allows the spill
slot allocators to check for these instructions and try to coalesce the
spill slots the two temporaries are allocated to.

1 files changed, 36 insertions, 0 deletions

diff --git a/lib/hipe/sparc/hipe_sparc_frame.erl b/lib/hipe/sparc/hipe_sparc_frame.erl
index 6f29c3c905..1f2a259ca1 100644
--- a/lib/hipe/sparc/hipe_sparc_frame.erl
+++ b/lib/hipe/sparc/hipe_sparc_frame.erl
@@ -82,6 +82,10 @@ do_insn(I, LiveOut, Context, FPoff) ->
       {do_pseudo_tailcall(I, Context), context_framesize(Context)};
     #pseudo_fmove{} ->
       {do_pseudo_fmove(I, Context, FPoff), FPoff};
+    #pseudo_spill_move{} ->
+      {do_pseudo_spill_move(I, Context, FPoff), FPoff};
+    #pseudo_spill_fmove{} ->
+      {do_pseudo_spill_fmove(I, Context, FPoff), FPoff};
     _ ->
       {[I], FPoff}
   end.
@@ -110,6 +114,22 @@ do_pseudo_move(I, Context, FPoff) ->
       end
   end.
 
+do_pseudo_spill_move(I, Context, FPoff) ->
+  #pseudo_spill_move{src=Src,temp=Temp,dst=Dst} = I,
+  case temp_is_pseudo(Src) andalso temp_is_pseudo(Dst) of
+    false -> % Register allocator changed its mind, turn back to move
+      do_pseudo_move(hipe_sparc:mk_pseudo_move(Src, Dst), Context, FPoff);
+    true ->
+      SrcOffset = pseudo_offset(Src, FPoff, Context),
+      DstOffset = pseudo_offset(Dst, FPoff, Context),
+      case SrcOffset =:= DstOffset of
+	true -> []; % omit move-to-self
+	false ->
+	  mk_load(hipe_sparc:mk_sp(), SrcOffset, Temp,
+		 mk_store(Temp, hipe_sparc:mk_sp(), DstOffset, []))
+      end
+  end.
+
 do_pseudo_fmove(I, Context, FPoff) ->
   Dst = hipe_sparc:pseudo_fmove_dst(I),
   Src = hipe_sparc:pseudo_fmove_src(I),
@@ -127,6 +147,22 @@ do_pseudo_fmove(I, Context, FPoff) ->
       end
   end.
 
+do_pseudo_spill_fmove(I, Context, FPoff) ->
+  #pseudo_spill_fmove{src=Src,temp=Temp,dst=Dst} = I,
+  case temp_is_pseudo(Src) andalso temp_is_pseudo(Dst) of
+    false -> % Register allocator changed its mind, turn back to fmove
+      do_pseudo_fmove(hipe_sparc:mk_pseudo_fmove(Src, Dst), Context, FPoff);
+    true ->
+      SrcOffset = pseudo_offset(Src, FPoff, Context),
+      DstOffset = pseudo_offset(Dst, FPoff, Context),
+      case SrcOffset =:= DstOffset of
+	true -> []; % omit move-to-self
+	false ->
+	  mk_fload(hipe_sparc:mk_sp(), SrcOffset, Temp)
+	    ++ mk_fstore(Temp, hipe_sparc:mk_sp(), DstOffset)
+      end
+  end.
+
 pseudo_offset(Temp, FPoff, Context) ->
   FPoff + context_offset(Context, Temp).