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2018-09-26beam_clean: Use maps and cerl_sets instead of dict and setsBjörn Gustavsson
Using maps and cerl_sets instead of dict and sets will slightly speed up the beam_clean pass for modules with many functions and/or calls to local functions.
2018-08-24Introduce a new SSA-based intermediate formatBjörn Gustavsson
v3_codegen is replaced by three new passes: * beam_kernel_to_ssa which translates the Kernel Erlang format to a new SSA-based intermediate format. * beam_ssa_pre_codegen which prepares the SSA-based format for code generation, including register allocation. Registers are allocated using the linear scan algorithm. * beam_ssa_codegen which generates BEAM assembly code from the SSA-based format. It easier and more effective to optimize the SSA-based format before X and Y registers have been assigned. The current optimization passes constantly have to make sure no "holes" in the X register assignments are created (that is, that no X register becomes undefined that an allocation instruction depends on). This commit also introduces the following optimizations: * Replacing of tuple matching of records with the is_tagged_tuple instruction. (Replacing beam_record.) * Sinking of get_tuple_element instructions to just before the first use of the extracted values. As well as potentially avoiding extracting tuple elements when they are not actually used on all executions paths, this optimization could also reduce the number values that will need to be stored in Y registers. (Similar to beam_reorder, but more effective.) * Live optimizations, removing the definition of a variable that is not subsequently used (provided that the operation has no side effects), as well strength reduction of binary matching by replacing the extraction of value from a binary with a skip instruction. (Used to be done by beam_block, beam_utils, and v3_codegen.) * Removal of redundant bs_restore2 instructions. (Formerly done by beam_bs.) * Type-based optimizations across branches. More effective than the old beam_type pass that only did type-based optimizations in basic blocks. * Optimization of floating point instructions. (Formerly done by beam_type.) * Optimization of receive statements to introduce recv_mark and recv_set instructions. More effective with far fewer restrictions on what instructions are allowed between creating the reference and entering the receive statement. * Common subexpression elimination. (Formerly done by beam_block.)
2018-08-17beam_bs: Remove optimizations that are easier done on SSA formatBjörn Gustavsson
The removal of redundant bs_restore2 instructions is done easier on the SSA format. Keep the rest of the optimizations, because they are easier to do on the BEAM instructions.
2018-06-18Update copyright yearHenrik Nord
2018-03-23Allow the match context identifier to be any termBjörn Gustavsson
During compilation, the bs_save2 and bs_restore2 instructions contain a match context reference. That reference is the variable name that holds the match context. beam_clean assumes that the reference always is an atom, which is not a safe assumption since integers are legal variable names in Core Erlang.
2018-02-14beam_block: Combine blocks when running beam_block the second timeBjörn Gustavsson
1a029efd1ad47f started to run the beam_block pass a second time, but it did not attempt to combine adjacent blocks. Combining adjacent blocks leads to many more opportunities for optimizations. After doing some diffing in generated code, it turns out that there is no benefit for beam_split to split out line instructions from blocks. It seems that the only reason it was done was to slightly simplify the implementation of the no_line_info option in beam_clean.
2017-08-12Introduce beam_utils:replace_labels/4Michał Muskała
2017-01-12beam_clean: Add types and specsBjörn Gustavsson
2016-03-15update copyright-yearHenrik Nord
2015-09-28Move select_val optimization from beam_clean to beam_peepBjörn Gustavsson
There is an optimization in beam_clean that will remove values having the same label as the failure label in a select_val instruction. Conceptually, this optimization is in the wrong module since ideally beam_clean is a mandatory pass that should not do optimizations. Furthermore, this part of beam_clean is called three times (from beam_dead, beam_peep, and as a compiler pass from the 'compile' module), but it only does useful one of the times it is called. Therefore, move this optimization to the beam_peep pass. The same optimization is done in beam_dead, but unfortunately it misses some opportunities for optimization because the code sharing optimization in beam_jump (share/1) runs after beam_dead. It would be more satisfactory to have this optimization only in beam_dead, but it turned out not to be trivial. If we try to run beam_jump:share/1 before beam_dead, some optimizations will no longer work in beam_dead because fallthroughs have been eliminated. For the moment, the possible solutions to this problem seems to involve more work and more complicated code than the gain from eliminating the duplicated optimization would gain.
2015-08-21beam_validator: Don't allow x(1023) to be usedBjörn Gustavsson
In 45f469ca0890, the BEAM loader started to use x(1023) as scratch register for some instructions. Therefore we should not allow x(1023) to be used in code emitted by the compiler.
2015-06-18Change license text to APLv2Bruce Yinhe
2015-04-22Move rewriting of bs_match from beam_clean to beam_zBjörn Gustavsson
The actual bs_match_string instruction has four operands: bs_match_string {f,Lbl} Ctxt NumBits {string,ListOfBytes} However, v3_codegen emits a more compact representation where the bits to match are packaged in a bitstring: bs_match_string {f,Lbl} Ctxt Bitstring Currently, beam_clean:clean_labels/1 will rewrite the compact representation to the final representation. That is unfortunate since clean_labels/1 is called by beam_dead, which means that the less compact representation will be introduced long before it is actually needed by beam_asm. It will also complicate any optimizations that we might want to do. Move the rewriting of bs_match_string from beam_clean:clean_labels/1 to the beam_z pass, which is the last pass executed before beam_validator and beam_asm.
2015-01-16beam_clean: Remove handling of forgotten instructionsBjörn Gustavsson
Commits b44f86b7 and 97953704 introduced translations of instructions in beam_a and beam_z, but forgot to remove the handling of them in beam_clean.
2014-02-13compiler: Change map instructions for fetching valuesBjörn-Egil Dahlberg
* Combine multiple get values with one instruction * Combine multiple check keys with one instruction
2014-01-28compiler: Implement different instructions for => and :=Björn Gustavsson
2014-01-28Implement support for maps in the compilerBjörn Gustavsson
To make it possible to build the entire OTP system, also define dummys for the instructions in ops.tab.
2013-09-12Remove ^L characters hidden randomly in the code. Not those used in text ↵Pierre Fenoll
files as delimiters. While working on a tool that processes Erlang code and testing it against this repo, I found out about those little sneaky 0xff. I thought it may be of help to other people build such tools to remove non-conforming-to-standard characters.
2013-01-25Update copyright yearsBjörn-Egil Dahlberg
2012-10-10Break apart tail-recursive call instructionsBjörn Gustavsson
Somewhat reduce the code bloat by eliminating special cases.
2012-10-10Rewrite select_val and select_tuple_arity to a select instructionBjörn Gustavsson
Eliminate some code bloat.
2012-10-09Rewrite binary creation instructions to bs_init instructionsBjörn Gustavsson
Rewrite the five binary creation instructions to a bs_init instruction, in order to somewhat reduce code bloat.
2012-10-09Rewrite bs_add, bs_utf*_size to BIF instructions in optimizationsBjörn Gustavsson
We can remove some code bloat by handling the special instructions as BIF instructions in the optimization passes. Also note that bs_utf*_size was not handled by beam_utils:check_liveness/3 (meaning the conservative answer instead of the correct answer would be returned).
2012-10-09Rewrite bs_put* instructions to a generic bs_put instructionBjörn Gustavsson
Seven bs_put_* instructions can be combined into one generic bs_put instruction to avoid some code bloat. That will also improve some optimizations (such as beam_trim) that did not handle all bs_put* variants.
2011-08-18compiler: Add no_line_info for suppressing line/1 instructionsBjörn Gustavsson
Also update the r12 and r13 options so that they imply no_line_info.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP