diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa_dead.erl')
| -rw-r--r-- | lib/compiler/src/beam_ssa_dead.erl | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/lib/compiler/src/beam_ssa_dead.erl b/lib/compiler/src/beam_ssa_dead.erl index 57b16883ed..2cca9ebadf 100644 --- a/lib/compiler/src/beam_ssa_dead.erl +++ b/lib/compiler/src/beam_ssa_dead.erl @@ -946,7 +946,7 @@ used_vars([{L,#b_blk{is=Is}=Blk}|Bs], UsedVars0, Skip0) -> %% shortcut_opt/1. Successors = beam_ssa:successors(Blk), - Used0 = used_vars_succ(Successors, L, UsedVars0), + Used0 = used_vars_succ(Successors, L, UsedVars0, []), Used = used_vars_blk(Blk, Used0), UsedVars = used_vars_phis(Is, L, Used, UsedVars0), @@ -969,19 +969,22 @@ used_vars([{L,#b_blk{is=Is}=Blk}|Bs], UsedVars0, Skip0) -> used_vars([], UsedVars, Skip) -> {UsedVars,Skip}. -used_vars_succ([S|Ss], L, UsedVars) -> - Live0 = used_vars_succ(Ss, L, UsedVars), +used_vars_succ([S|Ss], L, LiveMap, Live0) -> Key = {S,L}, - case UsedVars of + case LiveMap of #{Key:=Live} -> - ordsets:union(Live, Live0); + %% The successor has a phi node, and the value for + %% this block in the phi node is a variable. + used_vars_succ(Ss, L, LiveMap, ordsets:union(Live, Live0)); #{S:=Live} -> - ordsets:union(Live, Live0); + %% No phi node in the successor, or the value for + %% this block in the phi node is a literal. + used_vars_succ(Ss, L, LiveMap, ordsets:union(Live, Live0)); #{} -> - Live0 + %% A peek_message block which has not been processed yet. + used_vars_succ(Ss, L, LiveMap, Live0) end; -used_vars_succ([], _, _) -> - ordsets:new(). +used_vars_succ([], _, _, Acc) -> Acc. used_vars_phis(Is, L, Live0, UsedVars0) -> UsedVars = UsedVars0#{L=>Live0}, |