diff options
| -rw-r--r-- | lib/compiler/src/beam_ssa_opt.erl | 32 | ||||
| -rw-r--r-- | lib/compiler/test/float_SUITE.erl | 23 |
2 files changed, 39 insertions, 16 deletions
diff --git a/lib/compiler/src/beam_ssa_opt.erl b/lib/compiler/src/beam_ssa_opt.erl index bcf55f3fda..90c0d3cf16 100644 --- a/lib/compiler/src/beam_ssa_opt.erl +++ b/lib/compiler/src/beam_ssa_opt.erl @@ -911,6 +911,11 @@ ssa_opt_float({#st{ssa=Linear0,cnt=Count0}=St, FuncDb}) -> {Linear,Count} = float_opt(Linear0, Count0, Fs), {St#st{ssa=Linear,cnt=Count}, FuncDb}. +float_blk_is_in_guard(#b_blk{last=#b_br{fail=F}}, #fs{non_guards=NonGuards}) -> + not gb_sets:is_member(F, NonGuards); +float_blk_is_in_guard(#b_blk{}, #fs{}) -> + false. + float_non_guards([{L,#b_blk{is=Is}}|Bs]) -> case Is of [#b_set{op=landingpad}|_] -> @@ -920,21 +925,18 @@ float_non_guards([{L,#b_blk{is=Is}}|Bs]) -> end; float_non_guards([]) -> [?BADARG_BLOCK]. -float_opt([{L,#b_blk{last=#b_br{fail=F}}=Blk}|Bs0], - Count0, #fs{non_guards=NonGuards}=Fs) -> - case gb_sets:is_member(F, NonGuards) of +float_opt([{L,Blk}|Bs0], Count0, Fs) -> + case float_blk_is_in_guard(Blk, Fs) of true -> - %% This block is not inside a guard. - %% We can do the optimization. - float_opt_1(L, Blk, Bs0, Count0, Fs); - false -> %% This block is inside a guard. Don't do %% any floating point optimizations. {Bs,Count} = float_opt(Bs0, Count0, Fs), - {[{L,Blk}|Bs],Count} + {[{L,Blk}|Bs],Count}; + false -> + %% This block is not inside a guard. + %% We can do the optimization. + float_opt_1(L, Blk, Bs0, Count0, Fs) end; -float_opt([{L,Blk}|Bs], Count, Fs) -> - float_opt_1(L, Blk, Bs, Count, Fs); float_opt([], Count, _Fs) -> {[],Count}. @@ -1010,10 +1012,14 @@ float_conv([{L,#b_blk{is=Is0}=Blk0}|Bs0], Fail, Count0) -> float_maybe_flush(Blk0, #fs{s=cleared,fail=Fail,bs=Blocks}=Fs0, Count0) -> #b_blk{last=#b_br{bool=#b_var{},succ=Succ}=Br} = Blk0, - #b_blk{is=Is} = map_get(Succ, Blocks), + + %% If the success block starts with a floating point operation, we can + %% defer flushing to that block as long as it isn't a guard. + #b_blk{is=Is} = SuccBlk = map_get(Succ, Blocks), + SuccIsGuard = float_blk_is_in_guard(SuccBlk, Fs0), + case Is of - [#b_set{anno=#{float_op:=_}}|_] -> - %% The next operation is also a floating point operation. + [#b_set{anno=#{float_op:=_}}|_] when not SuccIsGuard -> %% No flush needed. {[],Blk0,Fs0,Count0}; _ -> diff --git a/lib/compiler/test/float_SUITE.erl b/lib/compiler/test/float_SUITE.erl index 831e8279aa..0fa8070dc8 100644 --- a/lib/compiler/test/float_SUITE.erl +++ b/lib/compiler/test/float_SUITE.erl @@ -21,15 +21,16 @@ -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, init_per_group/2,end_per_group/2, pending/1,bif_calls/1,math_functions/1,mixed_float_and_int/1, - subtract_number_type/1]). + subtract_number_type/1,float_followed_by_guard/1]). -include_lib("common_test/include/ct.hrl"). suite() -> [{ct_hooks,[ts_install_cth]}]. -all() -> +all() -> [pending, bif_calls, math_functions, - mixed_float_and_int, subtract_number_type]. + mixed_float_and_int, subtract_number_type, + float_followed_by_guard]. groups() -> []. @@ -187,5 +188,21 @@ fact(0, P) -> P; fact(1, P) -> P; fact(N, P) -> fact(N-1, P*N). +float_followed_by_guard(Config) when is_list(Config) -> + true = ffbg_1(5, 1), + false = ffbg_1(1, 5), + ok. + +ffbg_1(A, B0) -> + %% This is a non-guard block followed by a *guard block* that starts with a + %% floating point operation, and the compiler erroneously assumed that it + %% was safe to skip fcheckerror because the next block started with a float + %% op. + B = id(B0) / 1.0, + if + A - B > 0.0 -> true; + A - B =< 0.0 -> false + end. + id(I) -> I. |