| Age | Commit message (Collapse) | Author |
|---|
|
The compiler could sometimes emit unnecessary 'move'
instructions in the code for binary matching, for
example for this function:
escape(<<Byte, Rest/bits>>, Pos) when Byte >= 127 ->
escape(Rest, Pos + 1);
escape(<<Byte, Rest/bits>>, Pos) ->
escape(Rest, Pos + Byte);
escape(<<_Rest/bits>>, Pos) ->
Pos.
The generated code would look like this:
{function, escape, 2, 2}.
{label,1}.
{line,[{location,"t.erl",17}]}.
{func_info,{atom,t},{atom,escape},2}.
{label,2}.
{test,bs_start_match2,{f,1},2,[{x,0},0],{x,0}}.
{test,bs_get_integer2,
{f,4},
2,
[{x,0},
{integer,8},
1,
{field_flags,[{anno,[17,{file,"t.erl"}]},unsigned,big]}],
{x,2}}.
{'%',{bin_opt,[17,{file,"t.erl"}]}}.
{move,{x,0},{x,3}}. %% UNECESSARY!
{test,is_ge,{f,3},[{x,2},{integer,127}]}.
{line,[{location,"t.erl",18}]}.
{gc_bif,'+',{f,0},4,[{x,1},{integer,1}],{x,1}}.
{move,{x,3},{x,0}}. %% UNECESSARY!
{call_only,2,{f,2}}.
{label,3}.
{line,[{location,"t.erl",20}]}.
{gc_bif,'+',{f,0},4,[{x,1},{x,2}],{x,1}}.
{move,{x,3},{x,0}}. %% UNECESSARY!
{call_only,2,{f,2}}.
{label,4}.
{move,{x,1},{x,0}}.
return.
The redundant 'move' instructions have been marked.
To avoid the 'move' instructions, we can extend the existing
function is_context_unused/1 in v3_codegen. If v3_codegen can
know that the match context will not be used again, it can reuse
the register for the match context and avoid the extra 'move'
instructions.
https://bugs.erlang.org/browse/ERL-444
|
|
* maint:
Make handling of match contexts stricter
|
|
Enhance optimisations in beam_peep
|
|
beam_validator could fail issue a diagnostic when a register
that was supposed to be a match context was not guaranteed to
be a match context.
The bug was in merging of types. Merging of a match context with
another term would result in a match context. That is wrong. Merging
should produce a more general type, not a narrower type. Also, the
valid slots in two match contexts should be combined with 'band', not
'bor'.
|
|
Remove query keyword residues
|
|
When cleaning selects, it might happen we're left with only one pair. In such
case convert to a regular test + jump.
|
|
query was no longer a keyword since the commit 0dc3a29744bed0b7f483ad72e19773dc0982ea50 2012-11-19.
So the quotes around query, when it used as atom, no needed.
|
|
Conflicts:
OTP_VERSION
|
|
* maint-20:
Updated OTP version
Prepare release
Accept non-binary options as socket-options
Bump version
Fix broken handling of default values in extensions for PER
compiler: Fix live regs update on allocate in validator
Take fail labels into account when determining liveness in block ops
Check for overflow when appending binaries, and error out with system_limit
|
|
|
|
'john/compiler/fail-labels-in-blocks-otp-19/ERIERL-48/OTP-14522' into maint-20
* john/compiler/fail-labels-in-blocks-otp-19/ERIERL-48/OTP-14522:
compiler: Fix live regs update on allocate in validator
Take fail labels into account when determining liveness in block ops
|
|
|
|
'john/compiler/fail-labels-in-blocks-otp-18/ERIERL-48/OTP-14522' into maint
* john/compiler/fail-labels-in-blocks-otp-18/ERIERL-48/OTP-14522:
compiler: Fix live regs update on allocate in validator
Take fail labels into account when determining liveness in block ops
Conflicts:
lib/compiler/src/beam_utils.erl
|
|
The state without pruned registers was passed on to test_heap
causing the validator to belive registers that aren't live
actually are live.
|
|
The state without pruned registers was passed on to test_heap
causing the validator to belive registers that aren't live
actually are live.
|
|
|
|
bjorng/bjorn/compiler/improve-case-opt/ERL-452/OTP-14525
Generalize optimization of "one-armed" cases
|
|
Even though, it's not possible to have fall-throughs when entering the otp
pass, it can produce them itself and we're running the pass until fixpoint.
|
|
This makes other optimisations more efficient since we have less labels overall.
|
|
It can happen we have the following situation:
{test,is_tuple,Fail,[R1]}
{test,test_arity,Fail,[R1,N1]}
{get_tuple_element,R1,N2,R2}
{test,is_eq_exaqct,Fail,[R2,Atom]}
{jump,Fail}
Previously, the optimisation would eliminate the last is_eq_exact test, but
we can do more. If the register R2 is not used in Fail, we can eliminate the
get_tuple_element instruction as well as all the preceding tests. Ultimately,
the whole sequence can be replaced by:
{jump,Fail}
|
|
This is especially useful after inlining a function with a case.
Today the compiler would most probably be able to unify all the leafs of the
case during the sharing optimisation, but it would fail to unify the pattern
matching itself.
Naively running the optimisation multiple times wouldn't be able to find the
common code either, because it would differ in jump/fail targets of various
instructions.
To remedy this, after doing each sharing pass we traverse the code backwards
when reversing and update all the jump targets with the new targets that were
discovered during the unification pass. This allows running the optimisation
until fixpoint and makes sure all sharing opportunities will be discovered.
This optimisation also helps with the Elixir's `with/else` construct.
|
|
|
|
* maint:
sys_core_fold: Fix unsafe optimization of non-variable apply
Correct type specification in ssl:prf/5
|
|
A 'case' expression will force a stack frame (essentially in the same
way as a function call), unless it is at the end of a function.
In sys_core_fold there is an optimization that can optimize one-armed
cases such as:
case Expr of
Pat1 ->
DoSomething;
Pat2 ->
erlang:error(bad)
end,
MoreCode.
Because only one arm of the 'case' can succeed, the code after the
case can be move into the successful arm:
case Expr of
Pat1 ->
DoSomething,
MoreCode;
Pat2 ->
erlang:error(bad)
end.
Thus, the 'case' is at the end of the function and it will no longer
need a stack frame.
However, the optimization in sys_core_fold would not be applied if
there were more than one failing clause such as in this code:
case Expr of
Pat1 ->
DoSomething,
MoreCode;
Pat2 ->
erlang:error(bad);
_ ->
erlang:error(case_clause)
end.
Generalize the optimization to handle any number of failing
clauses at the end of the case.
Reported-by: bugs.erlang.org/browse/ERL-452
|
|
|
|
The sys_core_fold pass would do an unsafe "optimization" when an
apply operation did not have a variable in the function position
as in the following example:
> cat test1.core
module 'test1' ['test1'/2]
attributes []
'i'/1 =
fun (_f) -> _f
'test1'/2 =
fun (_f, _x) ->
apply apply 'i'/1 (_f) (_x)
end
> erlc test1.core
no_file: Warning: invalid function call
Reported-by: Mikael Pettersson
|
|
Add stacktrace entries to BIF calls from emulator
|
|
The goal of this change is to improve debugging of
emulator calls. For example, the following code
rem(1, y)
will error with atom `badarith` when y is 0 and the
stacktrace has no entry for `erlang:rem/2`, making
such cases very hard to debug. This patch makes it
so the stacktrace includes `erlang:rem(1, 0)`.
The following emulator BIFs have been changed:
* band/2
* bnot/1
* bor/2
* bsl/2
* bsr/2
* bxor/2
* div/2
* element/2
* int_div/2
* rem/2
* sminus/2
* splus/2
* stimes/2
|
|
Introduce a new core pass called sys_core_alias
OTP-14505
|
|
The goal of this pass is to find values that are built from
patterns and generate aliases for those values to remove
pressure from the GC. For example, this code:
example({ok, Val}) ->
{ok, Val}.
shall become:
example({ok, Val} = Tuple) ->
Tuple.
Currently this pass aliases tuple and cons nodes made of literals,
variables and other cons. The tuple/cons may appear anywhere in the
pattern and it will be aliased if used later on.
Notice a tuple/cons made only of literals is not aliased as it may
be part of the literal pool.
|
|
Tuple calls is the ability to invoke a function on a tuple
as first argument:
1> Var = dict:new().
{dict,0,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[]},
{{[],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[]}}}
2> Var:size().
0
This behaviour is considered by most to be undesired and confusing,
especially when it comes to errors. For example, imagine you invoke
"Mod:new()" where a Mod is an atom and you accidentally pass {ok, dict}.
It raises:
{undef,[{ok,new,[{ok,dict}],[]},...]}
As it attempts to invoke ok:new/1, which is really hard to debug
as there is no call to new/1 on the source code.
Furthemore, this behaviour is implemented at the VM level, which
imposes such semantics on all languages running on BEAM.
Since we cannot remove the behaviour above, this proposal makes the
behaviour opt-in with a compiler flag:
-compile(tuple_calls).
This means that, if a codebase relies on this functionality, they
can keep compatibility by adding configuring their build tool to
always use the 'tuple_calls' flag or explicitly on each module.
As long as the compile attribute above is listed, the codebase will
work on old and new Erlang versions alike. The only downside of the
current implementation is that modules compiled on OTP 20 that rely
on 'tuple_calls' will have to be recompiled to run with 'tuple_calls'
on OTP 21+.
|
|
|
|
|
|
* bjorn/compiler/fix-invalid-orddict:
v3_kernel: Keep orddicts sorted
sys_core_fold: Ensure that orddict keys are unique
|
|
* bjorn/cuddle-with-tests:
Eliminate warnings for unused variables
Remove unused functions in test emulator test suites
process_SUITE: Don't leave processes running
trace_port_SUITE: Don't leave processes running
tracer_SUITE: Don't leave processes running
trace_nif_SUITE: Don't leave processes running
trace_bif_SUITE: Don't leave processes running
trace_SUITE: Don't leave processes running
message_queue_data_SUITE: Don't leave processes running
Add informational test case z_SUITE:leaked_processes/1
busy_port_SUITE: Ensure that all created procesesses are killed
busy_port_SUITE: Eliminate warnings for unused variables
busy_port_SUITE: Eliminate 'export_all'
after_SUITE: Don't leave a process running
beam_type_SUITE: Add a test case for an already fixed bug
|
|
|
|
All keys in an orddict must be unique. sys_core_fold:sub_sub_scope/1
broke that rule. It was probably harmless, but it is better to
avoid such rule violations.
|
|
* hasse/unicode_atoms/OTP-14285:
compiler: Handle (bad) Unicode parse transform module names
kernel: Improve handling of Unicode filenames
stdlib: Handle Unicode atoms in ms_transform
stdlib: Improve Unicode handling of the Erlang parser
stdlib: Handle unknown compiler options with Unicode
stdlib: Handle Unicode macro names
stdlib: Correct Unicode handling in escript
dialyzer: Improve handling of Unicode
parsetools: Improve handling of Unicode atoms
stdlib: Handle Unicode atoms when formatting stacktraces
stdlib: Add more checks of module names to the linter
stdlib: Handle Unicode atoms better in io_lib_format
stdlib: Handle Unicode atoms in c.erl
|
|
|
|
https://bugs.erlang.org/browse/ERL-433
|
|
As part of sys_core_fold, variables involved in bit syntax
matching would be annotated when it would be safe for a later
pass to do the delayed sub-binary creation optimization.
An implicit assumption regarding the annotation was that the
code must not be further optimized. That assumption was broken
in 05130e48555891, which introduced a fixpoint iteration
(applying the optimizations until there were no more changes).
That means that a variable could be annotated as safe for
reusing the match context in one iteration, but a later iteration
could rewrite the code in a way that would make the optimization
unsafe.
One way to fix this would be to clear all reuse_for_context
annotations before each iteration. But that would be wasteful.
Instead I chose to fix the problem by moving out the annotation
code to a separate pass (sys_core_bsm) that is run later after
all major optimizations of Core Erlang has been done.
|
|
This reverts commit eaf8ca41dfa4850437ad270d3897399c9358ced0.
|
|
|
|
compile:forms/1,2 is documented to return:
{ok,ModuleName,BinaryOrCode}
However, if one of the options 'from_core', 'from_asm', or
'from_beam' is given, ModuleName will be returned as [].
A worse problem is that is that if one those options are
combined with the 'native' option, compilation will crash.
Correct compile:forms/1,2 to pick up the module name from
the forms provided (either Core Erlang, Beam assembly code,
or a Beam file).
Reported here: https://bugs.erlang.org/browse/ERL-417
|
|
Make it clear that is_tagged_tuple/4 was added in OTP 20 (not R17).
|
|
* bjorn/cuddle-with-tests:
code_SUITE: Remove unused functions
Eliminate warning for variable 'Config' being unused
compile_SUITE: Don't create a directory called 'core'
Don't crash in end_per_testcase/2 in code_SUITE:on_load_embedded/1
|
|
A core dump can't be created with the name 'core' if there is
a directory named 'core'.
Rename the test case from core/1 to core_pp/1 so that the directory
name can be the same as the test case name. It also makes sense
to use a less generic name for the test case.
|
|
Warn for potentially unsafe use of get_stacktrace/0
|
|
erlang:get_stacktrace/0 returns the stacktrace for the latest
exception. The problem is that the stacktrace is kept until the next
exception occurs. If the last exception was a 'function_clause' or a
'badarg', the arguments for the call are also kept forever. The
arguments can be terms of any size (potentially huge).
In a future release, we would like to only allow
erlang:get_stacktrace/0 from within a 'try' expression. That would
make it possible to clear the stacktrace when the 'try' expression is
exited.
The 'catch' expression has no natural end where the stacktrace could
be cleared. The stacktrace could be cleared at the end of the function
that the 'catch' occurs in, but that would cause problems in the
following scenario (from real life, but simplified):
try
...
catch _:_ ->
io:format(...),
io:format("~p\n", [erlang:get_stacktrace()])
end.
%% In io.erl.
format(Fmt, Args) ->
Res = case ... of
SomePattern ->
catch...
...;
SomeOtherPattern ->
%% Output the formatted string here
...
end,
clear_stacktrace(), %% Inserted by compiler.
Res.
The call to io:format() would always clear the stacktrace before
it could be retrieved.
That problem could be solved by tightning the scope in which the
stacktrace is kept, but the rules for how long erlang:get_stacktrace/0
would work would become complicated.
Therefore, the solution we suggest for a future major release of
OTP is that erlang:get_stacktrace/0 will return [] if it is called
outside the 'catch' part of a 'try' expression.
To help users prepare, introduce a warning when it is likely that
erlang:get_stacktrace/0 will always return an empty list, for example
in this code:
catch error(foo),
Stk = erlang:get_stacktrace()
or in this code:
try Expr
catch _:_ -> ok end,
Stk = erlang:get_stacktrace()
|
|
* bjorn/compiler/cover:
compiler.cover: Remove deleted module sys_pre_expand
Cover the first clause of v3_core:bin_expand_string/4
compile_SUITE: Test the r16, r17, r18, r19 options
erl_bifs: Remove pure BIFs serving no useful purpose
erl_bifs: Remove erlang:hash/2 from list of pure functions
|
