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| author | Björn Gustavsson <[email protected]> | 2016-05-25 06:15:18 +0200 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2016-05-25 16:41:27 +0200 |
| commit | a6edfacf112f3048630bbd002b1eb8d933ebb2df (patch) | |
| tree | d223d98f8864b7fd6fe807ac00a3802ccda4aecc /lib/compiler/src | |
| parent | c0a93fe2b9e36e00e9e3ebdec7840889ac571f6a (diff) | |
| download | otp-a6edfacf112f3048630bbd002b1eb8d933ebb2df.tar.gz otp-a6edfacf112f3048630bbd002b1eb8d933ebb2df.tar.bz2 otp-a6edfacf112f3048630bbd002b1eb8d933ebb2df.zip | |
beam_utils: Simplify handling of 'return' to eliminate uncovered line
Y registers are killed by the deallocate/1 instruction, so there is no
need to handle Y register in the return/1 instruction in
check_liveness/3.
There is also no need to keep check_liveness_live_ret/3 since it
is only used in one place.
Diffstat (limited to 'lib/compiler/src')
| -rw-r--r-- | lib/compiler/src/beam_utils.erl | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 47703b4aa3..cc5bb4b98b 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -324,8 +324,11 @@ check_liveness(R, [{deallocate,_}|Is], St) -> {y,_} -> {killed,St}; _ -> check_liveness(R, Is, St) end; -check_liveness(R, [return|_], St) -> - check_liveness_live_ret(R, 1, St); +check_liveness({x,_}=R, [return|_], St) -> + case R of + {x,0} -> {used,St}; + {x,_} -> {killed,St} + end; check_liveness(R, [{call,Live,_}|Is], St) -> case R of {x,X} when X < Live -> {used,St}; @@ -534,14 +537,6 @@ check_liveness_at(R, Lbl, #live{lbl=Ll,res=ResMemorized}=St0) -> check_liveness_ret(R, R, St) -> {used,St}; check_liveness_ret(_, _, St) -> {killed,St}. -check_liveness_live_ret({x,R}, Live, St) -> - if - R < Live -> {used,St}; - true -> {killed,St} - end; -check_liveness_live_ret({y,_}, _, St) -> - {killed,St}. - check_liveness_fail(_, _, _, 0, St) -> {killed,St}; check_liveness_fail(R, Op, Args, Fail, St) -> |