Age | Commit message (Collapse) | Author |
|
Summary: This commit simplifies the implementation of the "GC BIFs" so
that they no longer need to do a garbage collection, removing duplicate
code for all GC BIFs in the runtime system, as well as potentially
reducing the size of the loaded BEAM code by using shorter
instructions calling those BIFs.
A GC BIF is a guard BIF that will do a garbage
collection if it needs to build anything on the heap.
For example, `abs/1` is a GC BIF because it might need to
allocate space on the heap (if the result is a floating point
number or the resulting integer is a bignum).
Before R12, a guard BIF (such as `abs/1`) that need to allocate
heap space would allocate outside of process's main heap, in
a heap fragment.
GC BIFs were introduced in R12B to support literals. During garbage
collection it become necessary to quickly test whether a term was
a literal. To make the check simple, guards BIFs were no longer
allowed to create heap fragments. Instead GC BIFs were introduced.
In OTP 19, the implementation of literals was changed to support
storing messages in heap fragments outside of the main heap for a
process. That change again made it allowed for guard BIFs to create
heap fragments when they need to build terms on the heap.
It would even be possible for the guard BIFs to build directly
on the main heap if there is room there, because the compiler
assumes that a new `test_heap/2` instruction must be emitted
when building anything after calling a GC BIF. (We don't do that
in this commit; see below.)
This commit simplifies the implementation of the GC BIFs in
the runtime system.
Each GC BIF had a dual implementation: one that was used when the GC
BIF was called directly and one used when it was called via
`apply/3`. For example, `abs/1` was implemented in `abs_1()` and
`erts_gc_abs_1()`. This commit removes the GC version of each BIF. The
other version that allocates heap space using `HAlloc()` is updated to
use the new `HeapFragOnlyAlloc()` macro that will allocate heap
space in a heap fragment outside of the main heap.
Because the BIFs will allocate outside of the main heap, the same
`bif` instructions used by nonbuilding BIFs can be used for the
(former) GC BIFs. Those instructions don't use the macros that save
and restore the heap and stack pointers (SWAPOUT/SWAPIN). If the
former GC BIFs would build on the main heap, either new instructions
would be needed, or SWAPOUT/SWAPIN instructions would need to be added
to the `bif` instructions.
Instructions that call the former GC BIFs don't need the operand
that specifies the number of live X registers. Therefore, the
instructions that call the BIFs are usually one word shorter.
|
|
Sometimes when building a tuple, there is no way to avoid an
extra `move` instruction. Consider this code:
make_tuple(A) -> {ok,A}.
The corresponding BEAM code looks like this:
{test_heap,3,1}.
{put_tuple,2,{x,1}}.
{put,{atom,ok}}.
{put,{x,0}}.
{move,{x,1},{x,0}}.
return.
To avoid overwriting the source register `{x,0}`, a `move`
instruction is necessary.
The problem doesn't exist when building a list:
%% build_list(A) -> [A].
{test_heap,2,1}.
{put_list,{x,0},nil,{x,0}}.
return.
Introduce a new `put_tuple2` instruction that builds a tuple in a
single instruction, so that the `move` instruction can be eliminated:
%% make_tuple(A) -> {ok,A}.
{test_heap,3,1}.
{put_tuple2,{x,0},{list,[{atom,ok},{x,0}]}}.
return.
Note that the BEAM loader already combines `put_tuple` and `put`
instructions into an internal instruction similar to `put_tuple2`.
Therefore the introduction of the new instruction will not speed up
execution of tuple building itself, but it will be less work for
the loader to load the new instruction.
|
|
A lot of erts internal messages used behind APIs to create
non-blocking calls, e.g. port_command, would cause the seq_trace
token to be cleared from the caller when it should not.
This commit fixes that and adds asserts that makes sure
that all messages sent have to correct token set.
Fixes: ERL-602
|
|
|
|
|
|
If no message/signal is sent (to same destination)
then monitor signal is flushed when process is scheduled out.
|
|
|
|
|
|
|
|
|
|
|
|
On 64-bit machines where the C code is always at address below 4Gb,
pack one or more operands into the instruction word.
|
|
|
|
The BeamOp() macro in erl_vm.h is clumsy to use. All users
cast the return value to BeamInstr.
Define new macros that are easier to use. In the future,
we might want to pack an operand into the same word as
the pointer to the instruction, so we will define two macros.
BeamIsOpCode() is used to rewrite code like this:
if (Instr == (BeamInstr) BeamOp(op_i_func_info_IaaI) {
...
}
to:
if (BeamIsOpCode(Instr, op_i_func_info_IaaI)) {
...
}
BeamOpCodeAddr(op_apply_bif) is used when we need the address
for an instruction.
Also elimiminate the global variables em_* in beam_emu.c.
They are not really needed. Use the BeamOpCodeAddr() macro
instead.
|
|
* bjorn/erts/pack-combined:
Pack combined instructions
beam_makeops: Refactor code generation
Correct disassembly of select instructions
|
|
* lukas/erts/remove-dirty-scheduler-defines/OTP-14613:
erts: Remove possibility to disable dirty schedulers
|
|
Make sure to use the 'unpacked[-1]' when accessing the unpacked
arguments.
|
|
|
|
|
|
Pack sequences of trailing 'f' operands for instructions
such at jump_on_val or i_select_val_lins.
|
|
|
|
Relative failure in itself is not an optimization, but we plan to
pack failure labels in the future to save memory.
|
|
|
|
The 'S' operand type was added in 5bf73db9fd77.
|
|
The 'I' type can be replaced with 't' if we know that the value
will fit in 16 bits. The 'P' type can be replaced with 'Q' if
it is used for deallocating a stack frame.
|
|
Having the helper functions for map update knowing all the details
of operands for the instruction will make it difficult to make
improvements such as better packing.
|
|
As a preparation for potentially improving packing in the future,
we will need to make sure that packable types have a defined maximum
size.
The packer algorithm assumes that two 'I' operands can be packed
into one 64-bit word, but there are instructions that use an 'I'
operand to store a pointer. It only works because those instructions
are not packed for other reasons.
Introduce the 'W' type and use it for operands that don't fit in
32 bits.
|
|
The instruction put_map_assoc/5 (used for updating a map) has a
failure operand, but it can't actually fail provided that its "map"
argument is a map.
The following code:
M#{key=>value}.
will be compiled to:
{test,is_map,{f,3},[{x,0}]}.
{line,[...]}.
{put_map_assoc,{f,0},{x,0},{x,0},1,{list,[{atom,key},{atom,value}]}}.
return.
{label,3}.
%% Code that produces a 'badmap' exception follows.
Because of the is_map instruction, {x,0} always contains a map when
the put_map_assoc instruction is executed. Therefore we can remove
the failure operand. That will save one word, and also eliminate
two tests at run-time.
The only problem is that the compiler in OTP 17 did not emit a
is_map instruction before the put_map_assoc instruction. Therefore,
we must add an instruction that tests for a map if the code was
compiled with the OTP 17 compiler.
Unfortunately, there is no safe and relatively easy way to known that
the OTP 17 compiler was used, so we will check whether a compiler
before OTP 20 was used. OTP 20 introduced a new chunk type for atoms,
which is trivial to check.
|
|
|
|
This refactor was done using the unifdef tool like this:
for file in $(find erts/ -name *.[ch]); do unifdef -t -f defile -o $file $file; done
where defile contained:
#define ERTS_SMP 1
#define USE_THREADS 1
#define DDLL_SMP 1
#define ERTS_HAVE_SMP_EMU 1
#define SMP 1
#define ERL_BITS_REENTRANT 1
#define ERTS_USE_ASYNC_READY_Q 1
#define FDBLOCK 1
#undef ERTS_POLL_NEED_ASYNC_INTERRUPT_SUPPORT
#define ERTS_POLL_ASYNC_INTERRUPT_SUPPORT 0
#define ERTS_POLL_USE_WAKEUP_PIPE 1
#define ERTS_POLL_USE_UPDATE_REQUESTS_QUEUE 1
#undef ERTS_HAVE_PLAIN_EMU
#undef ERTS_SIGNAL_STATE
|
|
Take advantage of the fact that small maps have a tuple for keys.
When new map is constructed and all keys are literals, we can construct
the entire keys tuple as a literal.
This should reduce the memory of maps created with literal keys almost by half,
since they all can share the same keys tuple.
|
|
|
|
* lukas/erts/20_minor_fixes:
erts: Rebuild etc executables if config.h changes
erts: Fix new gcc warning in check io
kernel: Add mem check to prim_file:large_write tc
erts: Fix two compiler warnings on OS X
erts: Fix erts_debug:df function info output
erts: Get rid of some unused function warnings on os x
|
|
* rickard/sched_type_tests:
Fix dirty scheduler type tests
|
|
OTP-14331
* rickard/pcre-8.40:
Update documentation
Update README.pcre_update.md
Stack guard for PCRE
Adjust for incompatibility between PCRE 8.40 and perl 5.22.1
Generate re replacement and split tests with perl vsn 5.22.1
Fix re_SUITE:pcre_compile_workspace_overflow/1
Skip line with lockout of modifiers in PCRE tests
Update tests for PCRE version 8.40
Update PCRE to version 8.40
Conflicts:
erts/emulator/beam/beam_debug.c
|
|
|
|
The func_info instruction should also be dumped, so that we know
which function is which in the dump. This was accidentally removed
when introducing the new codeinfo/codemfa api.
|
|
Old test for dirty schedulers didn't work with Visual C++
|
|
|
|
|
|
|
|
Instead of passing around a file descriptor
use a function pointer to facilitate more advanced
backend write logic such as size limitation or compression.
|
|
|
|
|
|
This commit adds two new structs to be used to represent
erlang code in erts.
ErtsCodeInfo is used to describe the i_func_info header
that is part of all Export entries and the prelude of
each function. This replaces all the BeamInstr * that
were previously used to point to these locations.
After this change the code should never use BeamInstr *
with offsets to figure out different parts of the
func_info header.
ErtsCodeMFA is a struct that is used to descripe a
MFA in code. It is used within ErtsCodeInfo and also
in Process->current.
All function that previously took Eterm * or BeamInstr *
to identify a MFA now use the ErtsCodeMFA or ErtsCodeInfo
where appropriate.
The code has been tested to work when adding a new field to the
ErtsCodeInfo struct, but some updates are needed in ops.tab to
make it work.
|
|
Using the translation table in erts_gc_bifs[], we can now print
out the name of GC BIFs, instead of just the pointer value.
|
|
* bjorn/erts/beam_load:
Optimize get_tuple_element instructions that target Y registers
Mend beam_SUITE:packed_registers/1
Correct unpacking of 3 operands on 32-bit archictectures
Eliminate misleading #ifdef ARCH_64 in beam_opcodes.h
beam_debug: Correct masking when unpacking packed operands
|
|
|
|
|
|
The TMPBUF option is no longer needed due to is_literal test and NONE
was only used for initial debugging. So we remove the entire option.
|