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2016-12-02Merge branch 'egil/compiler/opt-maps-pattern-matching/OTP-14072'Björn-Egil Dahlberg
* egil/compiler/opt-maps-pattern-matching/OTP-14072: compiler: Add regression tests compiler: Optimize maps pattern matching compiler: Allow for unaligned match argument in value groups
2016-12-01compiler: Add regression testsBjörn-Egil Dahlberg
2016-12-01compiler: Optimize maps pattern matchingBjörn-Egil Dahlberg
2016-11-29Make warn_export_all the defaultRichard Carlsson
2016-11-29warn_obsolete_guard is already defaultRichard Carlsson
Update compiler documentation and remove superfluous erlc flags.
2016-11-28Merge branch 'egil/compiler/maps-warn-repeated-keys/OTP-14058'Björn-Egil Dahlberg
* egil/compiler/maps-warn-repeated-keys/OTP-14058: compiler: Test repeated map key warnings compiler: Warn for repeated identical map keys
2016-11-23Make use of the Header feature in yeccRichard Carlsson
2016-11-23Update obsolete author e-mailsRichard Carlsson
2016-11-23Correct copyright info on cerl-related filesRichard Carlsson
2016-11-23compiler: Test repeated map key warningsBjörn-Egil Dahlberg
2016-11-23compiler: Warn for repeated identical map keysBjörn-Egil Dahlberg
A map expression such as, #{'a' => 1, 'b' => 2, 'a' => 3} will produce a warning for the repeated key 'a'.
2016-11-23Merge branch 'maint'Björn Gustavsson
* maint: Update primary bootstrap document {yield/nb_yield}() limitation Suppress warnings from v3_kernel when inlining is turned on
2016-11-18compile_SUITE: Make sure that guards are optimizedBjörn Gustavsson
Guards should use the more efficient 'test' instructions, not 'bif' instructions. Add a test to make sure that the optimizations don't degrade. We do have to keep an exception list for functions where we can't replace all 'bif' calls with 'test' instructions. We try to keep that list a short as practically possible.
2016-11-18beam_dead: Remove redundant 'or' instructionBjörn Gustavsson
In practice, this optimization will only apply to contrived guards that are almost never used in real applications. The only reason we add this optimization is to help approach the goal of zero tolerance for 'bif' instructions instead of 'test' instructions in guards.
2016-11-18beam_dead: Remove redundant 'bif' instructionsBjörn Gustavsson
A 'bif' or 'gc_bif' instruction is redundant if it has the same failure label as a 'jump' instruction immediately following it. There is no need to test for liveness of the destination register, because the code at the failure label cannot safely assume that the destination register is initialized. See the comments in the code for further details. In practice, this optimization will only apply to contrived guards that are almost never used in real applications. The only reason we add this optimization is to help approach the goal of zero tolerance for 'bif' instructions instead of 'test' instructions in guards.
2016-11-18Add test using LFE-generated Core Erlang modulesBjörn Gustavsson
Ensure that correct (not necessarily optimal) code is generated for Core Erlang code not originating from v3_core.
2016-11-18Remove beam_boolBjörn Gustavsson
The guard optimizations in v3_kernel has removed the need for beam_bool.
2016-11-18v3_kernel: Generate optimized code for guardsBjörn Gustavsson
The compiler produces poor code for complex guard expressions with andalso/orelse. Here is an example from the filename module: -define(IS_DRIVELETTER(Letter),(((Letter >= $A) andalso (Letter =< $Z)) orelse ((Letter >= $a) andalso (Letter =< $z)))). skip_prefix(Name, false) -> Name; skip_prefix([L, DrvSep|Name], DrvSep) when ?IS_DRIVELETTER(L) -> Name; skip_prefix(Name, _) -> Name. beam_bool fails to simplify the code for the guard, leaving several 'bif' instructions: {function, skip_prefix, 2, 49}. {label,48}. {line,[{location,"filename.erl",187}]}. {func_info,{atom,filename},{atom,skip_prefix},2}. {label,49}. {test,is_ne_exact,{f,52},[{x,1},{atom,false}]}. {test,is_nonempty_list,{f,52},[{x,0}]}. {get_list,{x,0},{x,2},{x,3}}. {test,is_nonempty_list,{f,52},[{x,3}]}. {get_list,{x,3},{x,4},{x,5}}. {bif,'=:=',{f,52},[{x,1},{x,4}],{x,6}}. {test,is_ge,{f,50},[{x,2},{integer,65}]}. {bif,'=<',{f,52},[{x,2},{integer,90}],{x,7}}. {test,is_eq_exact,{f,51},[{x,7},{atom,false}]}. {test,is_ge,{f,50},[{x,2},{integer,97}]}. {bif,'=<',{f,52},[{x,2},{integer,122}],{x,7}}. {jump,{f,51}}. {label,50}. {move,{atom,false},{x,7}}. {label,51}. {bif,'=:=',{f,52},[{x,7},{atom,true}],{x,7}}. {test,is_eq_exact,{f,52},[{x,6},{atom,true}]}. {test,is_eq_exact,{f,52},[{x,7},{atom,true}]}. {move,{x,5},{x,0}}. return. {label,52}. return. We can add optimizations of guard tests to v3_kernel to achive a better result: {function, skip_prefix, 2, 49}. {label,48}. {line,[{location,"filename.erl",187}]}. {func_info,{atom,filename},{atom,skip_prefix},2}. {label,49}. {test,is_ne_exact,{f,51},[{x,1},{atom,false}]}. {test,is_nonempty_list,{f,51},[{x,0}]}. {get_list,{x,0},{x,2},{x,3}}. {test,is_nonempty_list,{f,51},[{x,3}]}. {get_list,{x,3},{x,4},{x,5}}. {test,is_eq_exact,{f,51},[{x,1},{x,4}]}. {test,is_ge,{f,51},[{x,2},{integer,65}]}. {test,is_lt,{f,50},[{integer,90},{x,2}]}. {test,is_ge,{f,51},[{x,2},{integer,97}]}. {test,is_ge,{f,51},[{integer,122},{x,2}]}. {label,50}. {move,{x,5},{x,0}}. return. {label,51}. return. Looking at the STDLIB application, there were 112 lines of BIF calls in guards that beam_bool failed to convert to test instructions. This commit eliminates all those BIF calls. Here is how I counted the instructions: $ PATH=$ERL_TOP/bin:$PATH erlc -I ../include -I ../../kernel/include -S *.erl $ grep "bif,'[=<>]" *.S | grep -v f,0 dets.S: {bif,'=:=',{f,547},[{x,4},{atom,read_write}],{x,4}}. dets.S: {bif,'=:=',{f,547},[{x,5},{atom,saved}],{x,5}}. dets.S: {bif,'=:=',{f,589},[{x,5},{atom,read}],{x,5}}. . . . $ grep "bif,'[=<>]" *.S | grep -v f,0 | wc 112 224 6765 $
2016-11-18Suppress warnings from v3_kernel when inlining is turned onBjörn Gustavsson
v3_kernel may produce unwanted and confusing warnings for code that has been inlined with the new inliner (cerl_inline). Consider this code: -compile(inline). compute1(X) -> add(X, 0). compute2(X, Y) -> add(X, Y). add(1, 0) -> 1; add(1, Y) -> %% "this clause cannot match..." 1 + Y; add(X, Y) -> X + Y. v3_kernel warns because add/2 has been inlined into compute1/1 and only the first clause in add/2 will match. But the other clauses are needed when add/2 is inlined into compute2/2, so the user cannot do anything to eliminate the warning (short of manually inlining add/2, defeating the purpose of the 'inline' option). The warning would be reasonable if compute2/2 didn't exist, but it would be too complicated for the compiler to figure whether a warning make sense or not. Therefore, suppress all warnings generated by v3_kernel if cerl_inline has been run. ERL-301
2016-11-13sys_core_fold: Remove unnecessary calls to opt_bool_case/1Björn Gustavsson
The fixpoint iteration added in 05130e48 makes those calls superfluous.
2016-11-13record_SUITE: Strengthen test of record access in guardsBjörn Gustavsson
2016-11-11guard_SUITE: Add more test of guardsBjörn Gustavsson
2016-11-11compile_SUITE: Smoke test and cover more of v3_kernel_ppBjörn Gustavsson
2016-11-03Merge branch 'gandrade/fmod/PR-1216/OTP-14000'Björn Gustavsson
* gandrade/fmod/PR-1216/OTP-14000: Add test cases for math:fmod/2 BIF Support math:fmod/2 BIF on compiler Add math:fmod/2 BIF
2016-11-02Add test cases for math:fmod/2 BIFGuilherme Andrade
2016-11-02Support math:fmod/2 BIF on compilerGuilherme Andrade
2016-10-28sys_core_fold: Use less effort optimizing not in letsBjörn Gustavsson
There are two calls opt_not_in_let(). Since 05130e4855 introduced iteration to a fixpoint, only the first call is needed. Removing the redundant call will slightly speed up compilation.
2016-10-28sys_core_fold: Eliminate complaint from core_lintBjörn Gustavsson
2016-10-28Merge branch 'maint'Björn Gustavsson
* maint: Don't copy funs into guards
2016-10-27Don't copy funs into guardsBjörn Gustavsson
Funs must not be created in guards. The instruction for creating a fun clobbers all X registers, which is a bad thing to do in a guard.
2016-10-26Merge branch 'maint'Björn Gustavsson
* maint: Don't let inline_list_funcs degrade optimizations
2016-10-24Don't let inline_list_funcs degrade optimizationsBjörn Gustavsson
83199af0263 refactored sys_core_fold to break out the code for the inline_lists_funcs option to its own module. Unfortunately, it also accidentally turned off compile-time evaluation of calls to BIFs with wholly or partial constant arguments. For example, the code for the following funtion gets much worse when inline_list_funcs is used: b() -> R0 = #r{}, R1 = setelement(1+2, R0, "deux"), R2 = setelement(1+3, R1, "trois"), R3 = setelement(1+5, R2, "cinq"), R4 = setelement(1+2, R3, "DEUX"), R4. ERL-285
2016-10-07Merge branch 'maint'Björn Gustavsson
* maint: beam_bsm: Eliminate unsafe optimization
2016-10-06beam_bsm: Eliminate unsafe optimizationBjörn Gustavsson
The following code causes a compiler failure: first_after(Data, Offset) -> case byte_size(Data) > Offset of false -> {First, Rest} = {ok, ok}, ok; true -> <<_:Offset/binary, Rest/binary>> = Data, %% 'Rest' saved in y(0) before the call. {First, _} = match_first(Data, Rest), %% When beam_bsm sees the code, the following line %% which uses y(0) has been optimized away. {First, Rest} = {First, Rest}, First end. match_first(_, <<First:1/binary, Rest/binary>>) -> {First, Rest}. Here is the error message from beam_validator: t: function first_after/2+15: Internal consistency check failed - please report this bug. Instruction: {call,2,{f,7}} Error: {multiple_match_contexts,[{x,1},0]}: Basically, what happens is that at time of code generation, the variable 'Rest' is needed after the call to match_first/2 and is therefore saved in y(0). When beam_bsm (a late optimization pass) sees the code, the use of y(0) following the call to match_first/2 has been optimized away. beam_bsm therefore assumes that the delayed sub-binary creation is safe. (Actually, it is safe, but beam_validator does not realize it.) The bug was caused by two separate commits: e199e2471a reduced the number of special cases to handle in BEAM optimization passed by breaking apart the tail-recursive call instructions (call_only and call_last) into separate instructions. Unfortunately, the special handling for tail calls was lost, which resulted in worse code (i.e. the delayed sub-binary creation optimization could not be applied). e1aa422290 tried to compensate, but did so in a way that was not always safe. Teaching beam_validator that this kind of code is safe would be expensive. Instead, we will undo the damage caused by the two commits. Re-introduce the special handling of tail-recursive calls in beam_bsm that was lost in the first commit. (Effectively) revert the change in the second commit. ERL-268
2016-10-05Merge branch 'maint'Björn Gustavsson
* maint: Update primary bootstrap beam_block: Avoid unsafe inclusion of get_map_elements in blocks
2016-10-05beam_block: Avoid unsafe inclusion of get_map_elements in blocksBjörn Gustavsson
c2035ebb8b restricted the get_map_elements instruction so that it could only occur at the beginning of a block. It turns out that including it anywhere in a block is unsafe. Therefore, never put get_map_elements instruction in blocks. (Also remove the beam_utils:join_even/2 function since it is no longer used.) ERL-266
2016-09-29Merge branch 'rickard/time-unit/OTP-13831'Rickard Green
* rickard/time-unit/OTP-13831: Replace usage of deprecated time units
2016-09-29compiler: Allow for unaligned match argument in value groupsBjörn-Egil Dahlberg
At this stage in match compilation we are allowed to change the alignment of arguments and constructors as long as they are the same aligned in the same group.
2016-09-29Merge branch 'josevalim/compiler/at-var/PR-1081/OTP-13924'Björn Gustavsson
* josevalim/compiler/at-var/PR-1081/OTP-13924: Use @ in variable names generated by core and kernel
2016-09-26sys_core_fold: Run optimizations to a fixpointBjörn Gustavsson
Run the optimizations until a fixpoint is reached, or until the maximum iteration count is reached. The hope is that in the future we can many small optimizations instead of optimizations that try to do everything in one pass. This change allows us to remove the ad-hoc calls to expr/2 to run more optimizations on a piece of code.
2016-09-26sys_core_fold: Improve case optimizationBjörn Gustavsson
The optimization that avoids building a tuple in a case expression would not work if any clause matched a tuple as in the following example: f(A, B) -> case {A,B} of {<<X>>,Y} -> {X,Y} end. The generated Core Erlang code would look like this (note the tuples in the case expression and the pattern): 'f'/2 = fun (_cor1,_cor0) -> case {_cor1,_cor0} of <{#{#<X>(8,1,'integer',['unsigned'|['big']])}#,Y}> when 'true' -> {X,Y} . . . end It is expected that the code should look like this (note that tuples have been replaced with "values"): 'f'/2 = fun (_cor1,_cor0) -> %% Line 5 case <_cor1,_cor0> of <#{#<X>(8,1,'integer',['unsigned'|['big']])}#,Y> -> {X,Y} . . . end While at it, also fix bugs in the handling of pattern with aliases. The bindings were produced in the wrong order (creating 'let's with referring to free variables), but in most cases the incorrect bindings were discarded later without causing any harm.
2016-09-26sys_core_fold: Correct scope verification codeBjörn Gustavsson
703e8f4490bf broke the scope verification code (by calling ordsets:is_subset/2 with an unsorted second argument). While we are it, also optimize the verification function by avoiding converting the map to a sorted list.
2016-09-26core_pp: Correct printing of map updatesBjörn Gustavsson
2016-09-26Use @ in variable names generated by core and kernelJosé Valim
The previous variable names can be generated by projects like LFE and Elixir, leading to possible conflicts. Our first to choice to solve such conflicts was to use $ but that's not a valid variable name in core. Therefore we picked @ which is currently supported and still reduces the chance of conflicts.
2016-09-21Simplify handling of internal BIFsBjörn Gustavsson
Do a simpler translation of internal BIFs. While we are it, also remove the dummy values of Index and Uniq from the make_fun internal operation.
2016-09-21v3_life: Eliminate special handling of guardsBjörn Gustavsson
Remove the special handling #k_try{} in guards in v3_life. If we introduce a new #k_protected{} record in v3_kernel, v3_life no longer needs to know whether it is processing guards or bodies.
2016-09-21Simplify beam_utilsBjörn Gustavsson
When beam_utils was first written, it did not have the functions for testing whether a register was not used. Those were added later, in sort of a hacky way. Also, is_killed*() and is_not_used*() for Y registers would return the same answer. Fix that to make the API more consistent (an Y register can only be killed by a deallocate/1 instruction). We will need to change beam_trim to call beam_utils:is_not_used/3 instead of beam_utils:is_killed/3.
2016-09-21bs_match_SUITE: Add a test case for beam_utilsBjörn Gustavsson
During development, a bug in beam_utils caused a compiler failure in xmerl. If the bug reappears, make sure that we catch it when compiling the compiler test suite.
2016-09-21bif_SUITE: Cover the remaining uncovered linesBjörn Gustavsson
2016-09-21erl_bifs: Remove error_logger:warning_map/0 as a safe BIFBjörn Gustavsson
There is no need to list every obscure safe BIF in erl_bifs:is_safe/3. The purpose of erl_bifs:is_safe/3 is merely to warn when the return value of one of the safe BIFs is ignored.
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