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path: root/erts/emulator/beam/big.h
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2018-07-27Change "can not" into "cannot"Raimo Niskanen
I did not find any legitimate use of "can not", however skipped changing e.g RFCs archived in the source tree.
2017-09-28Eliminate MY_IS_SSMALL()Björn Gustavsson
For a long time, there has been the two macros IS_SSMALL() and MY_IS_SSMALL() that do exactly the same thing. There should only be one, and it should be called IS_SSMALL(). However, we must decide which implementation to use. When MY_IS_SSMALL() was introduced a long time ago, it was the most efficient. In a modern C compiler, there might not be any difference. To find out, I used the following small C program to examine the code generation: #include <stdio.h> typedef unsigned int Uint32; typedef unsigned long Uint64; typedef long Sint; #define SWORD_CONSTANT(Const) Const##L #define SMALL_BITS (64-4) #define MAX_SMALL ((SWORD_CONSTANT(1) << (SMALL_BITS-1))-1) #define MIN_SMALL (-(SWORD_CONSTANT(1) << (SMALL_BITS-1))) #define MY_IS_SSMALL32(x) (((Uint32) ((((x)) >> (SMALL_BITS-1)) + 1)) < 2) #define MY_IS_SSMALL64(x) (((Uint64) ((((x)) >> (SMALL_BITS-1)) + 1)) < 2) #define MY_IS_SSMALL(x) (sizeof(x) == sizeof(Uint32) ? MY_IS_SSMALL32(x) : MY_IS_SSMALL64(x)) #define IS_SSMALL(x) (((x) >= MIN_SMALL) && ((x) <= MAX_SMALL)) void original(Sint n) { if (IS_SSMALL(n)) { printf("yes\n"); } } void enhanced(Sint n) { if (MY_IS_SSMALL(n)) { printf("yes\n"); } } gcc 7.2 produced the following code for the original() function: .LC0: .string "yes" original(long): movabs rax, 576460752303423488 add rdi, rax movabs rax, 1152921504606846975 cmp rdi, rax jbe .L4 rep ret .L4: mov edi, OFFSET FLAT:.LC0 jmp puts clang 5.0.0 produced the following code which is slightly better: original(long): movabs rax, 576460752303423488 add rax, rdi shr rax, 60 jne .LBB0_1 mov edi, .Lstr jmp puts # TAILCALL .LBB0_1: ret .Lstr: .asciz "yes" However, in the context of beam_emu.c, clang could produce similar to what gcc produced. gcc 7.2 produced the following code when MY_IS_SSMALL() was used: .LC0: .string "yes" enhanced(long): sar rdi, 59 add rdi, 1 cmp rdi, 1 jbe .L4 rep ret .L4: mov edi, OFFSET FLAT:.LC0 jmp puts clang produced similar code. This code seems to be the cheapest. There are four instructions, and there is no loading of huge integer constants.
2017-06-14Update copyright yearHans Nilsson
2017-05-16erts: Remove old unused functionsLukas Larsson
The functions have been found using: https://github.com/caolanm/callcatcher
2016-07-14erts: Cleanup a bunch of un-neccesary #ifndefsLukas Larsson
2016-03-15update copyright-yearHenrik Nord
2016-02-24Merge branch 'master' into sverk/master/halt-INT_MINSverker Eriksson
2016-02-24erts: Make erlang:halt() accept bignums as StatusSverker Eriksson
Just mask away the high bits to get a more tolerant erlang:halt that behaves the same on 32 and 64 bit architectures.
2016-02-02Better list_to_integerDmytro Lytovchenko
Now tries to use whole width of signed long (Sint) and this halves amount of multiplications needed to parse long integers. New code is 2-3 times faster than the old code for large inputs (tens and hundreds of digits), behavior should not change for small inputs. Test ran 10k times with GC forced between attempts. Was (R17): 720 el base 10: 0.14682 sec; base 16: 0.192722 sec; base 36: 0.337118 sec. 2800 el base 10: 1.794133 sec; base 16: 2.735106 sec; base 36: 4.761108 sec. 6500 el base 10: 9.316434 sec; base 16: 14.109469 sec; base 36: 25.319263 sec. Now (R19 Dev) 720 el base 10: 0.10265 sec; base 16: 0.10851 sec; base 36: 0.160478 sec. 2800 el base 10: 1.002793 sec; base 16: 1.360649 sec; base 36: 2.174309 sec. 6500 el base 10: 4.722197 sec; base 16: 6.60522 sec; base 36: 10.552795 sec. Added test for corner cases and sign bit corruption. Replaced macros with inline and hid it inside C file to not pollute global namespace Old bug in #define LG2_LOOKUP: Replaced with inline function and table recalculated for all bases 2 to 36 (was 2 to 64)
2016-01-25Moved do_list_to_integer from bif.c to big.cDmytro Lytovchenko
2015-06-24erts: Remove HALFWORD_HEAP definitionBjörn-Egil Dahlberg
2015-06-18Change license text to APLv2Bruce Yinhe
2015-06-15erts: Remove hashmap probabilistic heap overestimationSverker Eriksson
by adding a dynamic heap factory. "binary_to_term" is now a hybrid solution with both a call to decoded_size() to calculate needed heap space AND possible dynamic allocation of more heap space if needed for big maps. The heap size returned from decoded_size() is guaranteed to be sufficient for all term heap data except for hashmap nodes. All hashmap nodes are created at the end of dec_term() by invoking the heap factory interface that may allocate more heap space on process heap or in fragments. With this commit it is no longer guaranteed that a message is confined to only one heap fragment.
2015-03-20Introduce a new time APIRickard Green
The old time API is based on erlang:now/0. The major issue with erlang:now/0 is that it was intended to be used for so many unrelated things. This tied these unrelated operations together and unnecessarily caused performance, scalability as well as accuracy, and precision issues for operations that do not need to have such issues. The new API spreads different functionality over multiple functions in order to improve on this. The new API consists of a number of new BIFs: - erlang:convert_time_unit/3 - erlang:monotonic_time/0 - erlang:monotonic_time/1 - erlang:system_time/0 - erlang:system_time/1 - erlang:time_offset/0 - erlang:time_offset/1 - erlang:timestamp/0 - erlang:unique_integer/0 - erlang:unique_integer/1 - os:system_time/0 - os:system_time/1 and a number of extensions of existing BIFs: - erlang:monitor(time_offset, clock_service) - erlang:system_flag(time_offset, finalize) - erlang:system_info(os_monotonic_time_source) - erlang:system_info(time_offset) - erlang:system_info(time_warp_mode) - erlang:system_info(time_correction) - erlang:system_info(start_time) See the "Time and Time Correction in Erlang" chapter of the ERTS User's Guide for more information.
2014-08-08erts: Fix neg int overflow when sint is min sizeLukas Larsson
When INT64_MIN is the value of a Sint64 we have to first cast it to an Uint64 before negating it. Otherwise we get an integer overflow which is undefined behaviour and in gcc 4.9 this results in -0 instead of -9223372036854775808 in gcc 4.8.
2014-01-22erts: Fix crash when comparing very large floats with integersSverker Eriksson
big_buf was one word too short on 32-bit emulators causing memory corruption. Seems like this did not cause a problem before the ESTACK memory layout was changed in 172ebf11dc455e22b87f.
2013-02-22Update copyright yearsBjörn-Egil Dahlberg
2013-02-14Add new binary conversion bifsLukas Larsson
Added: binary_to_integer/1,2, integer_to_binary/1,2
2011-12-02Get cerl and distribution working in Win64Patrik Nyblom
Can still not setup -a, but cerl works.
2011-10-11Update integer and floating point number comparisonsLukas Larsson
For floating point values which are greater than 9007199254740990.0 or smaller than -9007199254740990.0, the floating point numbers are now converted to integers during comparison with an integer. This makes number comparisons transitive for large floating point numbers.
2011-05-06erts_printf %R for relative ets-terms in halfword-vmSverker Eriksson
Conflicts: erts/emulator/beam/erl_printf_term.c
2011-02-18HALFWORD ETS Fix copyright year in some source filesSverker Eriksson
2011-02-03HALFWORD ETS relative termsSverker Eriksson
In halfword emulator, make ETS use a variant of the internal term format that uses relative offsets instead of absolute pointers. This will allow storage in high memory (>4G). Preprocessor macros (like list_val_rel(TERM,BASE)) are used to make normal (fullword) emulator almost completely unchanged while still reusing most of the code.
2010-07-23NIF 64-bit integer supportSverker Eriksson
2010-03-22Merge branch 'pan/otp_8332_halfword' into devErlang/OTP
* pan/otp_8332_halfword: Teach testcase in driver_suite the new prototype for driver_async wx: Correct usage of driver callbacks from wx thread Adopt the new (R13B04) Nif functionality to the halfword codebase Support monitoring and demonitoring from driver threads Fix further test-suite problems Correct the VM to work for more test suites Teach {wordsize,internal|external} to system_info/1 Make tracing and distribution work Turn on instruction packing in the loader and virtual machine Add the BeamInstr data type for loaded BEAM code Fix the BEAM dissambler for the half-word emulator Store pointers to heap data in 32-bit words Add a custom mmap wrapper to force heaps into the lower address range Fit all heap data into the 32-bit address range
2010-03-10Correct the VM to work for more test suitesPatrik Nyblom
The following test suites now work: send_term_SUITE trace_nif_SUITE binary_SUITE match_spec_SUITE node_container_SUITE beam_literals_SUITE Also add a testcases for system_info({wordsize,internal|external}).
2010-03-10Fix the BEAM dissambler for the half-word emulatorPatrik Nyblom
2010-03-10Store pointers to heap data in 32-bit wordsPatrik Nyblom
Store Erlang terms in 32-bit entities on the heap, expanding the pointers to 64-bit when needed. This works because all terms are stored on addresses in the 32-bit address range (the 32 most significant bits of pointers to term data are always 0). Introduce a new datatype called UWord (along with its companion SWord), which is an integer having the exact same size as the machine word (a void *), but might be larger than Eterm/Uint. Store code as machine words, as the instructions are pointers to executable code which might reside outside the 32-bit address range. Continuation pointers are stored on the 32-bit stack and hence must point to addresses in the low range, which means that loaded beam code much be placed in the low 32-bit address range (but, as said earlier, the instructions themselves are full words). No Erlang term data can be stored on C stacks (enforced by an earlier commit). This version gives a prompt, but test cases still fail (and dump core). The loader (and emulator loop) has instruction packing disabled. The main issues has been in rewriting loader and actual virtual machine. Subsystems (like distribution) does not work yet.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP