From ce51e9969798cef67b4d00e03a9e59c7986a8bdd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 30 Jan 2018 13:45:41 +0100 Subject: Fix incorrect handling of floating point instructions 1a029efd1ad47f started to run the beam_block pass a second time. Since it is run after introduction of the optimized floating point instructions, it must handle those instructions correctly. In particular, it must be careful when hoisting allocation instructions. For example, the following code: {test_heap,{alloc,[{words,0},{floats,1}]},5}. . . . {fmove,{fr,2},{x,0}}. {allocate_zero,1,4}. must not be rewritten to: {test_heap,{alloc,[{words,0},{floats,1}]},5}. . . . {allocate_zero,1,4}. {fmove,{fr,2},{x,0}}. because beam_validator will not consider it safe. (The code may actually be safe depending on what the code between the two allocation instructions do.) https://bugs.erlang.org/browse/ERL-555 --- lib/compiler/src/beam_block.erl | 1 + lib/compiler/test/beam_block_SUITE.erl | 14 ++++++++++++-- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/lib/compiler/src/beam_block.erl b/lib/compiler/src/beam_block.erl index d0536e0669..ecefeeae54 100644 --- a/lib/compiler/src/beam_block.erl +++ b/lib/compiler/src/beam_block.erl @@ -222,6 +222,7 @@ move_allocates_1([I|Is], Acc) -> move_allocates_1(Is, [I|Acc]); move_allocates_1([], Acc) -> Acc. +alloc_may_pass({set,_,[{fr,_}],fmove}) -> false; alloc_may_pass({set,_,_,{alloc,_,_}}) -> false; alloc_may_pass({set,_,_,{set_tuple_element,_}}) -> false; alloc_may_pass({set,_,_,put_list}) -> false; diff --git a/lib/compiler/test/beam_block_SUITE.erl b/lib/compiler/test/beam_block_SUITE.erl index fac18789e0..38ead96cc8 100644 --- a/lib/compiler/test/beam_block_SUITE.erl +++ b/lib/compiler/test/beam_block_SUITE.erl @@ -22,7 +22,7 @@ -export([all/0,suite/0,groups/0,init_per_suite/1,end_per_suite/1, init_per_group/2,end_per_group/2, get_map_elements/1,otp_7345/1,move_opt_across_gc_bif/1, - erl_202/1,repro/1,local_cse/1]). + erl_202/1,repro/1,local_cse/1,second_block_pass/1]). %% The only test for the following functions is that %% the code compiles and is accepted by beam_validator. @@ -41,7 +41,8 @@ groups() -> move_opt_across_gc_bif, erl_202, repro, - local_cse + local_cse, + second_block_pass ]}]. init_per_suite(Config) -> @@ -295,6 +296,15 @@ local_cse_4() -> do_local_cse_4(X, Y, Z) -> {X,Y,Z}. +%% Tests previously found bugs when running beam_block the second time. + +second_block_pass(_Config) -> + [#{dts:=5.0}] = second_1([#{dts => 10.0}], 2.0), + ok. + +second_1(Fs, TS) -> + [F#{dts=>DTS / TS} || #{dts:=DTS} = F <- Fs]. + %%% %%% Common functions. %%% -- cgit v1.2.3