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author | John Högberg <john@erlang.org> | 2019-08-07 14:00:09 +0200 |
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committer | John Högberg <john@erlang.org> | 2019-08-07 16:47:25 +0200 |
commit | 6ae9975689858d0e0c9af0a36869c012bb3762c0 (patch) | |
tree | 973ca6e2ad428001d6e3a0ce30fa18ef574b4933 /lib/compiler/src/beam_ssa_lint.erl | |
parent | db8a1822079b309075dd5be9fa1cb2019da2c61d (diff) | |
download | erlang-6ae9975689858d0e0c9af0a36869c012bb3762c0.tar.gz |
compiler: Fix awkward match context substitution
This worked out by accident since codegen never actually looks at
the arguments for 'succeeded'; it just assumes that they reference
the preceding instruction.
Diffstat (limited to 'lib/compiler/src/beam_ssa_lint.erl')
-rw-r--r-- | lib/compiler/src/beam_ssa_lint.erl | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/lib/compiler/src/beam_ssa_lint.erl b/lib/compiler/src/beam_ssa_lint.erl index b2a8c1a0d1..224095d4c4 100644 --- a/lib/compiler/src/beam_ssa_lint.erl +++ b/lib/compiler/src/beam_ssa_lint.erl @@ -65,7 +65,13 @@ format_error({{_M,F,A},{phi_inside_block, Name, Id}}) -> [F, A, format_var(Name), Id]); format_error({{_M,F,A},{undefined_label_in_phi, Label, I}}) -> io_lib:format("~p/~p: Unknown block label ~p in phi node ~ts", - [F, A, Label, format_instr(I)]). + [F, A, Label, format_instr(I)]); +format_error({{_M,F,A},{succeeded_not_preceded, I}}) -> + io_lib:format("~p/~p: ~ts does not reference the preceding instruction", + [F, A, format_instr(I)]); +format_error({{_M,F,A},{succeeded_not_last, I}}) -> + io_lib:format("~p/~p: ~ts is not the last instruction in its block", + [F, A, format_instr(I)]). format_instr(I) -> [$',beam_ssa_pp:format_instr(I),$']. @@ -229,6 +235,18 @@ vvars_block(Id, State0) -> State :: #vvars{}. vvars_block_1([], State) -> State; +vvars_block_1([#b_set{dst=OpVar,args=OpArgs}=I, + #b_set{op=succeeded,args=[OpVar],dst=SuccVar}], State) -> + ok = vvars_assert_args(OpArgs, I, State), + vvars_save_var(SuccVar, vvars_save_var(OpVar, State)); +vvars_block_1([#b_set{op=succeeded,args=Args}=I | [_|_]], State) -> + ok = vvars_assert_args(Args, I, State), + %% 'succeeded' must be the last instruction in its block. + throw({succeeded_not_last, I}); +vvars_block_1([#b_set{op=succeeded,args=Args}=I], State)-> + ok = vvars_assert_args(Args, I, State), + %% 'succeeded' must be be directly preceded by the operation it checks. + throw({succeeded_not_preceded, I}); vvars_block_1([#b_set{ dst = Dst, op = phi } | Is], State) -> %% We don't check phi node arguments at this point since we may not have %% visited their definition yet. They'll be handled later on in |