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authorMagnus Lång <[email protected]>2017-03-16 15:30:00 +0100
committerMagnus Lång <[email protected]>2017-03-16 20:49:42 +0100
commitc52b2cf226cb3f1bb1b16bee28d47785506adff3 (patch)
treef016829f93e26db7fe7e2329ace868f4b2442510 /lib/hipe/arm/hipe_arm_frame.erl
parentd1d26f4bf9da3cc5eab4e918df771d67fe9e6bb5 (diff)
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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.
Diffstat (limited to 'lib/hipe/arm/hipe_arm_frame.erl')
-rw-r--r--lib/hipe/arm/hipe_arm_frame.erl22
1 files changed, 22 insertions, 0 deletions
diff --git a/lib/hipe/arm/hipe_arm_frame.erl b/lib/hipe/arm/hipe_arm_frame.erl
index e323907e31..a1004fb609 100644
--- a/lib/hipe/arm/hipe_arm_frame.erl
+++ b/lib/hipe/arm/hipe_arm_frame.erl
@@ -69,6 +69,8 @@ do_insn(I, LiveOut, Context, FPoff) ->
do_pseudo_call_prepare(I, FPoff);
#pseudo_move{} ->
{do_pseudo_move(I, Context, FPoff), FPoff};
+ #pseudo_spill_move{} ->
+ {do_pseudo_spill_move(I, Context, FPoff), FPoff};
#pseudo_tailcall{} ->
{do_pseudo_tailcall(I, Context), context_framesize(Context)};
_ ->
@@ -100,6 +102,26 @@ pseudo_offset(Temp, FPoff, Context) ->
FPoff + context_offset(Context, Temp).
%%%
+%%% Moves from one spill slot to another
+%%%
+
+do_pseudo_spill_move(I, Context, FPoff) ->
+ #pseudo_spill_move{dst=Dst, temp=Temp, src=Src} = 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_arm:mk_pseudo_move(Dst, Src), 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('ldr', Temp, SrcOffset, mk_sp(),
+ mk_store('str', Temp, DstOffset, mk_sp(), []))
+ end
+ end.
+
+%%%
%%% Return - deallocate frame and emit 'ret $N' insn.
%%%