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2016-04-07Remove unused variables after code generationBjörn Gustavsson
The removal of instructions on the left side of a transformation is done while generating the code for the left side. Postpone removal of unused variables to a later, separate passes to allow more variables to be eliminated after the optimizations passes introduced in the previous commits.
2016-04-07Avoid rebuilding unchanged instructionsBjörn Gustavsson
In transformations such as: move S X0=x==0 | line Loc | call_ext Ar Func => \ line Loc | move S X0 | call_ext Ar Func we can avoid rebuilding the last instruction in the sequence by introducing a 'keep' instruction. Currently, there are only 13 transformations that are hit by this optimization, but most of them are frequently used.
2016-04-07Introduce a 'rename' instructionBjörn Gustavsson
Introduce a 'rename' instruction that can be used to optimize simple renaming with unchanged operands such as: get_tuple_element Reg P Dst => i_get_tuple_element Reg P Dst By allowing it to lower the arity of instruction, transformations such as the following can be handled: trim N Remaining => i_trim N All in all, currently 67 transformations can be optimized in this way, including some commonly used ones.
2016-04-07Simplify window management for the transformation engineBjörn Gustavsson
Generic instructions have a min_window field. Its purpose is to avoid calling transform_engine() when there are too few instructions in the current "transformation window" for a transformation to succeed. Currently it does not do much good since the window size will be decremented by one before being used. The reason for the subtraction is probably that in some circumstances in the past, the loader could read past the end of the BEAM module while attempting to fetch instructions to increase the window size. Therefore, it would not be safe to just remove the subtraction by one. The simplest and safest solution seems to always ensure that there are always at least TWO instructions when calling transform_engine(). That will be safe, as long as a BEAM module is always finished with an int_code_end/0 that is not involved in any transformation.
2016-04-07Eliminate allocation of variables in transform_engine()Björn Gustavsson
When an instruction with a variable number operands (such as select_val) is seen of the left side of a transformation, the 'next_arg' instruction will allocate a buffer to fit all variables and all operands will be copied into the buffer. Very often, the 'commit' instruction will never be reached because of a test or predicate failing or because of a short window; in that case, the variable buffer will be deallocated. Note that originally there were only few instructions with a variable number of operands, but now common operations such as tuple building also have a variable number of operands. To avoid those frequent allocations and deallocations, modify the 'next_arg' instruction to only save a pointer to the first of the "rest" arguments. Also move the deallocation of the instructions on the left side from the 'commit' instruction to the 'end' instruction to ensure that 'store_rest_args' will still work.
2015-09-09Merge branch 'maint'Rickard Green
* maint: Add configure switch --disable-saved-compile-time Fix ethread events with timeout Improve choice of clock sources at build time
2015-09-09Add configure switch --disable-saved-compile-timeRickard Green
2015-07-06Improve unpacking performance on x86_64Björn Gustavsson
When unpacking operands on 64-bit CPUs, use a smarter mask to help the compiler optimize the code. It turns out that on x86_64, if we use the mask 0xFFFFUL (selecting the 16 least significant bits), the compiler can combine a move and a mask operation into the single insruction 'movzwl', which will eliminate one instruction.
2015-07-06Eliminate prefetch for conditional instructionsBjörn Gustavsson
Not pre-fetching in conditional instructions (instructions that use -fail_action) seems to improve performance slightly. The reason for that is that conditional instructions may jump to the failure label, wasting the pre-fetched instruction. Another reason is that that many conditional instructions do a function call, and the register pressure is therefore high. Avoiding the pre-fetch may reduce the register pressure and pontentially result in more efficient code.
2015-07-03Teach beam_makeops to pack operands for move3 and move_windowBjörn Gustavsson
It is currently only possible to pack up to 4 operands. However, the move_window4 instrucion has 5 operands and move_window5 and move3 instrucations have 6 operands. Teach beam_makeops to pack instructions with 5 or 6 operands. Also rewrite the move_window instructions in beam_emu.c to macros to allow their operands to get packed.
2015-07-03beam_makeops: Eliminate unnecessary masking when packing 3 operandsBjörn Gustavsson
When packing 3 operands into one word, there would be an unnecessary mask operation when extracting the last operand.
2015-07-03Make the 'r' operand type optionalBjörn Gustavsson
The 'r' type is now mandatory. That means in order to handle both of the following instructions: move x(0) y(7) move x(1) y(7) we would need to define two specific operations in ops.tab: move r y move x y We want to make 'r' operands optional. That is, if we have only this specific instruction: move x y it will match both of the following instructions: move x(0) y(7) move x(1) y(7) Make 'r' optional allows us to save code space when we don't want to make handling of x(0) a special case, but we can still use 'r' to optimize commonly used instructions.
2015-07-03Allow X and Y registers to be overloaded with any literalBjörn Gustavsson
Consider the try_case_end instruction: try_case_end s The 's' operand type means that the operand can either be a literal of one of the types atom, integer, or empty list, or a register. That worked well before R12. In R12 additional types of literals where introduced. Because of way the overloading was done, an 's' operand cannot handle the new types of literals. Therefore, code such as the following is necessary in ops.tab to avoid giving an 's' operand a literal: try_case_end Literal=q => move Literal x | try_case_end x While this work, it is error-prone in that it is easy to forget to add that kind of rule. It would also be complicated in case we wanted to introduce a new kind of addition operator such as: i_plus jssd Since there are two 's' operands, two scratch registers and two 'move' instructions would be needed. Therefore, we'll need to find a smarter way to find tag register operands. We will overload the pid and port tags for X and Y register, respectively. That works because pids and port are immediate values (fit in one word), and there are no literals for pids and ports.
2015-07-03Change the meaning of 'x' in a transformationBjörn Gustavsson
The purpose of this series of commits is to improve code generation for the Clang compiler. As a first step we want to change the meaning of 'x' in a transformation such as: operation Literal=q => move Literal x | operation x Currently, a plain 'x' means reg[0] or x(0), which is the first element in the X register array. That element is distinct from r(0) which is a variable in process_main(). Therefore, since r(0) and x(0) are currently distinct it is fine to use x(0) as a scratch register. However, in the next commit we will eliminate the separate variable for storing the contents of X register zero (thus, x(0) and r(0) will point to the same location in the X register array). Therefore, we must use another scratch register in transformation. Redefine a plain 'x' in a transformation to mean x(1023). Also define SCRATCH_X_REG so that we can refer to the register by name from C code.
2015-07-03beam_makeops: Eliminate crash because of unsafe packingBjörn Gustavsson
Consider an hypothetical instruction: do_something x x c The loader would crash if we tried to load an instance of the instruction with the last operand referencing a literal: {do_something,{x,0},{x,1},{literal,{a,b,c}}} Teach beam_makeops to turn off packing for such unsafe instructions.
2015-06-24erts: Remove HALFWORD_HEAP definitionBjörn-Egil Dahlberg
2015-06-18Change license text to APLv2Bruce Yinhe
2014-11-26Sort keys before generatingLukas Larsson
This has to be done in order to consistently generate the same file so that we do not get rebuilds all the time.
2014-06-03erts: Fix git version scriptLukas Larsson
2014-02-19Misc adjustments of OTP versionRickard Green
2014-01-28BEAM loader: Support preservation of extra operand in transformsBjörn Gustavsson
It was not possible to preserve extra arguments in transformations. The following (hypothetical) example will now work: some_op Lit=c SizeArg Rest=* => move Lit x | some_op x SizeArg Rest
2014-01-09Fix issues with new versioningRickard Green
2013-09-13erts: Fix loading of NIF library with unicode in pathSverker Eriksson
2013-08-28erts: Remove unused constant DRIVER_TAB_SIZESverker Eriksson
2013-08-21erts: Add support for static linked-in driversLukas Larsson
None of the OTP linked-in driver are supported
2013-08-21erts: Add option to include nifs staticallyLukas Larsson
Both crypto and asn1 are supported.
2013-07-11erts: Add cflags, ldflags and config.h into executableLukas Larsson
2013-02-14Remove surplus echosLukas Larsson
2013-02-13Include git sha in prompt if availableLukas Larsson
The sha will only be included if there is no tag starting with OTP_R* associated with the sha. This is because we do not want the sha to show on offical releases.
2013-01-25Update copyright yearsBjörn-Egil Dahlberg
2012-10-22beam_makeops: Turn on warnings and eliminate existing warningsBjörn Gustavsson
2012-10-15beam_makeops: Eliminate a deprecation warningBjörn Gustavsson
Perl 5.16.1 (and perhaps other versions) issues the following warning: defined(@array) is deprecated at utils/beam_makeops line 1714. (Maybe you should just omit the defined()?) for the following line: $prev_last = pop(@{$gen_transform{$key}}) if defined @{$gen_transform{$key}}; # LINE 1714 The documentation for "defined" says that its use on hashes and arrays is deprecated and that it may stop working in a future release. Simply removing "defined" (as suggested by the warning message) will not work, as there will be an error when trying to use an undefined value as an array reference: Can't use an undefined value as an ARRAY reference at utils/beam_makeops line 1714. What we must do is to check whether $gen_transform{$key} is defined before trying to use it as an array reference. Noticed-by: Tuncer Ayaz
2012-08-31Merge branch 'maint'Björn-Egil Dahlberg
Conflicts: lib/diameter/autoconf/vxworks/sed.general xcomp/README.md
2012-08-31Update copyright yearsBjörn-Egil Dahlberg
2012-08-27Merge branch 'maint'Björn Gustavsson
* maint: make_preload: Don't fail if Perl's default file encoding is UTF-8
2012-08-27make_preload: Don't fail if Perl's default file encoding is UTF-8Björn Gustavsson
Setting Perl's default encoding for files to UTF-8, for example like this: PERL_UNICODE=DS make would crash the build with a message similar to: form size 1413 greater than size 1237 of module at utils/make_preload line 175, <FILE> chunk 1. Tell Perl to interpret the data in BEAM files as binary by using the binmode() function. The binmode() function existed before Unicode support was added to Perl, which means that make_preload should work even in old versions of Perl. Noticed-by: Aaron Harnly
2012-06-25Don't go to single-scheduler mode when managing breakpointsBjörn Gustavsson
Calls to erlang:set_trace_pattern/3 will no longer block all other schedulers. We will still go to single-scheduler mode when new code is loaded for a module that is traced, or when loading code when there is a default trace pattern set. That is not impossible to fix, but that requires much closer cooperation between tracing BIFs and the loader BIFs.
2012-03-30Update copyright yearsBjörn-Egil Dahlberg
2012-03-22beam_makeops: Add a simple preprocessorBjörn Gustavsson
2011-12-09Update copyright yearsBjörn-Egil Dahlberg
2011-12-02Build Win64 Erlang emulator using MSYSunknown
Still does not run, just compiles.
2011-10-26Change the calling convention for BIFsBjörn Gustavsson
The current calling convention for BIFs makes it necessary to handle each arity specially, since each argument for the BIF also becomes an argument for the C function implementing the BIF, which makes it hard to allow BIFs with any number of arguments. Change the calling convention for BIFs, so that BIF arguments are passed in an array to the C function implementing the BIF.
2011-10-13make_preload: Don't output a C comment start inside a commentBjörn Gustavsson
We already avoid outputting a comment terminator ("*/") inside a comment to avoid causing a syntax error. Also avoid outputting the start of a comment ("/*") to avoid causing a compiler warning. Noticed-by: Tuncer Ayaz
2011-10-11Print transformtions sorted on the name of the first instructionBjörn Gustavsson
2011-10-11Share code for call of predicate and transformation functionsBjörn Gustavsson
2011-10-11Introduce 'try_me_else_fail'Björn Gustavsson
2011-10-11Combine 'store_var' with 'next_arg'Björn Gustavsson
'store_var' is always followed by 'next_arg'.
2011-10-11Merge 'next_instr' and 'is_op' into 'next_instr'Björn Gustavsson
'next_instr' is always followed by 'is_op'.
2011-10-11Merge 'new_instr' and 'store_op' into 'new_instr'Björn Gustavsson
Since the 'new_instr' instruction always occurs before the 'store_op' instruction, we can merge the instructions into one. Also, there is no need to include the arity of the BEAM instruction as an operand, since the arity can be looked up based on the opcode.
2011-10-11Combine a 'call' instruction with the following 'end' instructionBjörn Gustavsson
A 'call' instruction in the loader transformation language is always followed by an 'end' instruction, so we can replace the 'call' instruction with a 'call_end' instruction.