From 9b347a42a23540eab2f3fd8bf75190a69b5ebb31 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 26 Apr 2018 22:22:56 +0200 Subject: Correct beam_utils:is_killed/3 (again) beam_utils:is_killed/3 could incorrectly indicate that a register was killed. The previous fix is 5da6b91ecab6c. --- lib/compiler/src/beam_utils.erl | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 1ddad30328..f57a7af1ab 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -377,7 +377,7 @@ check_liveness(R, [{test,_,{f,Fail},As}|Is], St0) -> {killed,St1} -> check_liveness(R, Is, St1); {exit_not_used,St1} -> - check_liveness(R, Is, St1); + not_used(check_liveness(R, Is, St1)); {not_used,St1} -> not_used(check_liveness(R, Is, St1)); {used,_}=Used -> @@ -395,14 +395,14 @@ check_liveness(R, [{select,_,_,Fail,Branches}|_], St) -> check_liveness_everywhere(R, [Fail|Branches], St); check_liveness(R, [{jump,{f,F}}|_], St) -> check_liveness_at(R, F, St); -check_liveness(R, [{case_end,Used}|_], St) -> - check_liveness_ret(R, Used, St); +check_liveness(R, [{case_end,Used}|_], St) -> + check_liveness_exit(R, Used, St); check_liveness(R, [{try_case_end,Used}|_], St) -> - check_liveness_ret(R, Used, St); + check_liveness_exit(R, Used, St); check_liveness(R, [{badmatch,Used}|_], St) -> - check_liveness_ret(R, Used, St); -check_liveness(_, [if_end|_], St) -> - {killed,St}; + check_liveness_exit(R, Used, St); +check_liveness(R, [if_end|_], St) -> + check_liveness_exit(R, ignore, St); check_liveness(R, [{func_info,_,_,Ar}|_], St) -> case R of {x,X} when X < Ar -> {used,St}; @@ -658,8 +658,9 @@ check_liveness_at(R, Lbl, #live{lbl=Ll,res=ResMemorized}=St0) -> not_used({used,_}=Res) -> Res; not_used({_,St}) -> {not_used,St}. -check_liveness_ret(R, R, St) -> {used,St}; -check_liveness_ret(_, _, St) -> {killed,St}. +check_liveness_exit(R, R, St) -> {used,St}; +check_liveness_exit({x,_}, _, St) -> {killed,St}; +check_liveness_exit({y,_}, _, St) -> {exit_not_used,St}. %% check_liveness_block(Reg, [Instruction], State) -> %% {killed | not_used | used | alloc_used | transparent,State'} -- cgit v1.2.3