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authorBjörn Gustavsson <[email protected]>2011-04-06 10:57:15 +0200
committerBjörn Gustavsson <[email protected]>2011-04-12 05:52:57 +0200
commitce34176deaffd219e921cb70f271bbc693061fb6 (patch)
tree405880d7952e3e359add6ff5cb83353627204490
parentc30b5cb6ada1fd119356f54c90a2f660d5f08c1d (diff)
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beam_dead: Remove uncoverable case clause in update_value_dict/3
Because the code generator (v3_codegen) would not include the same value more than once in a select_val/3 instruction and because a label can only be referenced by one select_val/3 instruction, there is no way that the correct value could already be in the gb_tree. (Even if it could happen, this change is safe because only opportunity for an optimization would be missed; incorrect code would not be generated.)
-rw-r--r--lib/compiler/src/beam_dead.erl1
1 files changed, 0 insertions, 1 deletions
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl
index 135c7757c5..0afb027d3a 100644
--- a/lib/compiler/src/beam_dead.erl
+++ b/lib/compiler/src/beam_dead.erl
@@ -293,7 +293,6 @@ update_value_dict([Lit,{f,Lbl}|T], Reg, D0) ->
Key = {Lbl,Reg},
D = case gb_trees:lookup(Key, D0) of
none -> gb_trees:insert(Key, Lit, D0); %New.
- {value,Lit} -> D0; %Already correct.
{value,inconsistent} -> D0; %Inconsistent.
{value,_} -> gb_trees:update(Key, inconsistent, D0)
end,