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| author | Björn Gustavsson <[email protected]> | 2012-11-26 12:28:07 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2012-11-26 14:00:37 +0100 |
| commit | debb6589b998b37d02a52d55f12a2117b2dd0e38 (patch) | |
| tree | 26933c0a8b929b03b1c1d0b81c17e912ad211f0e | |
| parent | 4b01f5b318a866fc5fb9392ddadd1fa54f862692 (diff) | |
| download | otp-debb6589b998b37d02a52d55f12a2117b2dd0e38.tar.gz otp-debb6589b998b37d02a52d55f12a2117b2dd0e38.tar.bz2 otp-debb6589b998b37d02a52d55f12a2117b2dd0e38.zip | |
beam_utils: Improve is_not_used/3 for bit syntax matching
| -rw-r--r-- | lib/compiler/src/beam_utils.erl | 18 |
1 files changed, 5 insertions, 13 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 8b661e6901..8af0447f63 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -263,19 +263,11 @@ check_liveness(R, [{test,_,{f,Fail},As}|Is], St0) -> {_,_}=Other -> Other end end; -check_liveness(R, [{test,_,{f,Fail},Live,Ss,_}|Is], St0) -> - case R of - {x,X} -> - case X < Live orelse member(R, Ss) of - true -> {used,St0}; - false -> check_liveness_at(R, Fail, St0) - end; - {y,_} -> - case check_liveness_at(R, Fail, St0) of - {killed,St} -> check_liveness(R, Is, St); - {_,_}=Other -> Other - end - end; +check_liveness(R, [{test,Op,Fail,Live,Ss,Dst}|Is], St) -> + %% Check this instruction as a block to get a less conservative + %% result if the caller is is_not_used/3. + Block = [{set,[Dst],Ss,{alloc,Live,{bif,Op,Fail}}}], + check_liveness(R, [{block,Block}|Is], St); check_liveness(R, [{select,_,R,_,_}|_], St) -> {used,St}; check_liveness(R, [{select,_,_,Fail,Branches}|_], St) -> |