diff options
| -rw-r--r-- | lib/compiler/src/beam_bool.erl | 12 | ||||
| -rw-r--r-- | lib/compiler/test/andor_SUITE.erl | 30 |
2 files changed, 37 insertions, 5 deletions
diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl index ffe5cdb501..dcc6ad4c7c 100644 --- a/lib/compiler/src/beam_bool.erl +++ b/lib/compiler/src/beam_bool.erl @@ -173,7 +173,7 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) -> %% whether the optimized code is guaranteed to work in the same %% way as the original code. %% -%% Throws an exception if the optmization is not safe. +%% Throw an exception if the optimization is not safe. %% ensure_opt_safe(Bl, NewCode, OldIs, Fail, PreceedingCode, St) -> %% Here are the conditions that must be true for the @@ -190,10 +190,10 @@ ensure_opt_safe(Bl, NewCode, OldIs, Fail, PreceedingCode, St) -> %% by the code that follows. %% %% 3. Any register that is assigned a value in the optimized - %% code must be UNUSED or KILLED in the following code. - %% (Possible future improvement: Registers that are known - %% to be assigned the SAME value in the original and optimized - %% code don't need to be unused in the following code.) + %% code must be UNUSED or KILLED in the following code + %% (because the register might be assigned the wrong value, + %% and even if the value is right it might no longer be + %% assigned on *all* paths leading to its use). InitInPreceeding = initialized_regs(PreceedingCode), @@ -310,6 +310,8 @@ dst_regs([{set,[D],_,{bif,_,{f,_}}}|Is], Acc) -> dst_regs(Is, [D|Acc]); dst_regs([{set,[D],_,{alloc,_,{gc_bif,_,{f,_}}}}|Is], Acc) -> dst_regs(Is, [D|Acc]); +dst_regs([{set,[D],_,move}|Is], Acc) -> + dst_regs(Is, [D|Acc]); dst_regs([_|Is], Acc) -> dst_regs(Is, Acc); dst_regs([], Acc) -> ordsets:from_list(Acc). diff --git a/lib/compiler/test/andor_SUITE.erl b/lib/compiler/test/andor_SUITE.erl index 6e3ac4d4f4..a460d54239 100644 --- a/lib/compiler/test/andor_SUITE.erl +++ b/lib/compiler/test/andor_SUITE.erl @@ -390,6 +390,15 @@ before_and_inside_if(Config) when is_list(Config) -> ?line yes = before_and_inside_if([], [], x), ?line yes = before_and_inside_if([], [b], delete), ?line yes = before_and_inside_if([], [b], x), + + ?line {ch1,ch2} = before_and_inside_if_2([a], [b], blah), + ?line {ch1,ch2} = before_and_inside_if_2([a], [b], xx), + ?line {ch1,ch2} = before_and_inside_if_2([a], [], blah), + ?line {ch1,ch2} = before_and_inside_if_2([a], [], xx), + ?line {no,no} = before_and_inside_if_2([], [b], blah), + ?line {no,no} = before_and_inside_if_2([], [b], xx), + ?line {ch1,no} = before_and_inside_if_2([], [], blah), + ?line {no,ch2} = before_and_inside_if_2([], [], xx), ok. %% Thanks to Simon Cornish and Kostis Sagonas. @@ -408,6 +417,27 @@ before_and_inside_if(XDo1, XDo2, Do3) -> yes end. +%% Thanks to Simon Cornish. +%% Used to generate code that would not set {y,0} on +%% all paths before its use (and therefore fail +%% validation by the beam_validator). +before_and_inside_if_2(XDo1, XDo2, Do3) -> + Do1 = (XDo1 =/= []), + Do2 = (XDo2 =/= []), + CH1 = if Do1 == true; + Do1 == false,Do2==false,Do3 == blah -> + ch1; + true -> + no + end, + CH2 = if Do1 == true; + Do1 == false,Do2==false,Do3 == xx -> + ch2; + true -> + no + end, + {CH1,CH2}. + %% Utilities. check(V1, V0) -> |