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| author | Michał Muskała <[email protected]> | 2017-08-26 15:15:01 +0200 |
|---|---|---|
| committer | Michał Muskała <[email protected]> | 2017-09-08 01:49:10 +0200 |
| commit | f9a323d10a9f5da305cbdec632d6bdf7ad4770b5 (patch) | |
| tree | 7c71ba5bf06ea9b13f3846f05a767be19895399d /lib | |
| parent | 5d124efc4f8408cdbe2f23ca6b233b932f1dd7c6 (diff) | |
| download | otp-f9a323d10a9f5da305cbdec632d6bdf7ad4770b5.tar.gz otp-f9a323d10a9f5da305cbdec632d6bdf7ad4770b5.tar.bz2 otp-f9a323d10a9f5da305cbdec632d6bdf7ad4770b5.zip | |
Optimise equality comparisons
* In both loader and compiler, make sure constants are always the second
operand - many passes of the compiler assume that's always the case.
* In loader rewrite is_eq_exact with same arguments to skip the instruction
and with different constants move one to an x register to maintain
the properly outlined above.
* The same (but in reverse) is done with the is_ne_exact, where we rewrite
to an unconditional jump or add a move to an x register.
* All of the above allow to replace is_eq_exact_fss with is_eq_exact_fyy and
is_ne_exact_fss with is_ne_exact_fSS as those are the only possibilities left.
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/compiler/src/beam_utils.erl | 15 | ||||
| -rw-r--r-- | lib/compiler/test/guard_SUITE.erl | 4 |
2 files changed, 19 insertions, 0 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 52ed1c7ca0..a4c65397df 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -32,6 +32,11 @@ -import(lists, [map/2,member/2,sort/1,reverse/1,splitwith/2]). +-define(is_const(Val), (element(1, Val) =:= integer orelse + element(1, Val) =:= float orelse + element(1, Val) =:= atom orelse + element(1, Val) =:= literal)). + %% instruction() describes all instructions that are used during optimzation %% (from beam_a to beam_z). -type instruction() :: atom() | tuple(). @@ -197,10 +202,20 @@ bif_to_test('>', [A,B], Fail) -> {test,is_lt,Fail,[B,A]}; bif_to_test('<', [_,_]=Ops, Fail) -> {test,is_lt,Fail,Ops}; bif_to_test('>=', [_,_]=Ops, Fail) -> {test,is_ge,Fail,Ops}; bif_to_test('==', [A,nil], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('==', [nil,A], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('==', [C,A], Fail) when ?is_const(C) -> + {test,is_eq,Fail,[A,C]}; bif_to_test('==', [_,_]=Ops, Fail) -> {test,is_eq,Fail,Ops}; +bif_to_test('/=', [C,A], Fail) when ?is_const(C) -> + {test,is_ne,Fail,[A,C]}; bif_to_test('/=', [_,_]=Ops, Fail) -> {test,is_ne,Fail,Ops}; bif_to_test('=:=', [A,nil], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('=:=', [nil,A], Fail) -> {test,is_nil,Fail,[A]}; +bif_to_test('=:=', [C,A], Fail) when ?is_const(C) -> + {test,is_eq_exact,Fail,[A,C]}; bif_to_test('=:=', [_,_]=Ops, Fail) -> {test,is_eq_exact,Fail,Ops}; +bif_to_test('=/=', [C,A], Fail) when ?is_const(C) -> + {test,is_ne_exact,Fail,[A,C]}; bif_to_test('=/=', [_,_]=Ops, Fail) -> {test,is_ne_exact,Fail,Ops}; bif_to_test(is_record, [_,_,_]=Ops, Fail) -> {test,is_record,Fail,Ops}. diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl index ccb9b58225..d96cfdb7ac 100644 --- a/lib/compiler/test/guard_SUITE.erl +++ b/lib/compiler/test/guard_SUITE.erl @@ -1291,6 +1291,10 @@ rel_ops(Config) when is_list(Config) -> true = any_atom /= id(42), true = [] /= id(42), + %% Coverage of beam_utils:bif_to_test/3 + Empty = id([]), + ?T(==, [], Empty), + ok. -undef(TestOp). |