This improves performance in several ways. Separate functions are
used depending on whether the caller has a hash value computed or not.
* src/fns.c (hash_lookup_with_hash, hash_lookup_get_hash): New.
(hash_lookup): Remove hash return argument.
All callers adapted.
hash_lookup_with_hash hash_hash_t arg
Produce synthetic backtrace entries for `aref` and `aset` byte-ops
when the index is non-fixnum, or is out of range for vector or record
arguments (bug#64613).
* src/bytecode.c (exec_byte_code): Detect type and range errors
in-line for aref and aset.
* src/data.c (syms_of_data): Declare symbols Qaref and Qaset.
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp-tests--byte-op-error-cases): Add test cases.
Include calls to these primitives from byte-compiled code in
backtraces. For nth and elt, not all errors are covered.
(Bug#64613)
* src/bytecode.c (exec_byte_code): Add error backtrace records for
car, cdr, setcar, setcdr, nth and elt.
* src/data.c (syms_of_data): Add missing defsyms for car, setcar,
setcdr, nth and elt.
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp-tests--error-frame, bytecomp-tests--byte-op-error-cases)
(bytecomp--byte-op-error-backtrace): New test.
* src/editfns.c (narrow_to_region_internal): New function, which
contains the body previously in 'Fnarrow_to_region' but accepts
a third argument.
(Fnarrow_to_region): Use the new function. Update the docstring.
(Fwiden): Update the docstring.
* src/lisp.h: Prototype of the new function.
* src/xdisp.c (handle_fontified_prop): Use the new function instead
of 'Fnarrow_to_region'.
* src/process.c (Finternal_default_process_filter):
* src/lread.c (readevalloop): Remove the third argument to
'Fnarrow_to_region'.
* src/bytecode.c (exec_byte_code):
* lisp/emacs-lisp/comp.el (comp-limplify-lap-inst):
* lisp/emacs-lisp/bytecomp.el: Restore the statu quo ante.
* etc/NEWS: Remove the entry about the new optional argument.
* doc/lispref/positions.texi (Narrowing): Update the documentation.
* src/editfns.c (Fnarrow_to_region): Add the parameter to the
function, and handle it. Update docstring.
(unwind_locked_begv, unwind_locked_zv): New functions.
(Fwiden): Do nothing when restrictions are locked. Update
docstring.
(syms_of_editfns): Replace the 'inhibit-widen' symbol and variable
with a 'restrictions-locked' symbol and variable. Update docstring.
* src/xdisp.c (handle_fontified_prop): Use Fnarrow_to_region with
the new parameter.
(unwind_narrowed_zv): Remove function.
* src/process.c (Finternal_default_process_filter): Add a third
argument to Fnarrow_to_region.
* src/lread.c (readevalloop): Add a third argument to
Fnarrow_to_region.
* src/bytecode.c (exec_byte_code): Add a third argument to
Fnarrow_to_region.
* etc/NEWS (like): Mention the new parameter of 'narrow-to-region'.
* doc/lispref/positions.texi (Narrowing): Document it.
This is a cosmetic change only; there is no change in behaviour.
* lisp/emacs-lisp/bytecomp.el:
* src/bytecode.c (BYTE_CODES, exec_byte_code):
Update and/or remove incorrect, outdated or useless comments.
Clarify. Reorder where appropriate. Rename Bsave_current_buffer to
Bsave_current_buffer_OBSOLETE and Bsave_current_buffer_1 to
Bsave_current_buffer, reflecting the state since 1996.
* src/lisp.h (lisp_h_Qni): New macro.
(DEFUN): Use it.
* src/alloc.c (syms_of_alloc): Use it.
* src/bytecode.c (Fbyte_code): Fix Lisp_Object/int mixup.
* src/bytecode.c (valid_sp): static, not INLINE, as INLINE
should be used only in headers and between INLINE_HEADER_BEGIN
and INLINE_HEADER_END. No need for ‘inline’ here.
Using a plain C struct instead of type-punning Lisp_Object stack slots
makes the bytecode interpreter code more type-safe and potentially
faster (from better alias analysis), and the special-purpose accessors
are no longer needed. It also reduces the stack requirements when
using 64-bit Lisp_Object on 32-bit platforms.
* src/bytecode.c (enum stack_frame_index)
(sf_get_ptr, sf_set_ptr, sf_get_lisp_ptr, sf_set_lisp_ptr,
sf_get_saved_pc, sf_set_saved_pc): Remove.
(BC_STACK_SIZE): Now in bytes, not Lisp words.
(struct bc_frame): New.
(init_bc_thread, mark_bytecode, Finternal_stack_stats, valid_sp)
(exec_byte_code):
* src/lisp.h (struct handler, get_act_rec, set_act_rec):
Adapt to new struct bc_frame.
* src/bytecode.c (Fbyte_code):
* src/composite.c (Fclear_composition_cache):
Prefer CALLN to doing it by hand.
* src/fns.c (ccall2): Remove. All uses replaced by CALLN.
Use a dedicated stack for bytecode, instead of using the C stack.
Stack frames are managed explicitly and we stay in the same
exec_byte_code activation throughout bytecode function calls and
returns. In other words, exec_byte_code no longer uses recursion
for calling bytecode functions.
This results in better performance, and bytecode recursion is no
longer limited by the size of the C stack. The bytecode stack is
currently of fixed size but overflow is handled gracefully by
signalling a Lisp error instead of the hard crash that we get now.
In addition, GC marking of the stack is now faster and more precise.
Full precision could be attained if desired.
* src/alloc.c (ATTRIBUTE_NO_SANITIZE_ADDRESS): Make non-static.
* src/bytecode.c (enum stack_frame_index, BC_STACK_SIZE)
(sf_get_ptr, sf_set_ptr, sf_get_lisp_ptr, sf_set_lisp_ptr)
(sf_get_saved_pc, sf_set_saved_pc, init_bc_thread, free_bc_thread)
(mark_bytecode, Finternal_stack_stats, valid_sp): New.
(exec_byte_code): Adapt to use the new bytecode stack.
(syms_of_bytecode): Add defsubr.
* src/eval.c (unwind_to_catch): Restore saved stack frame.
(push_handler_nosignal): Save stack frame.
* src/lisp.h (struct handler): Add act_rec member.
(get_act_rec, set_act_rec): New.
* src/thread.c (mark_one_thread): Call mark_bytecode.
(finalize_one_thread): Free bytecode thread state.
(Fmake_thread, init_threads): Set up bytecode thread state.
* src/thread.h (struct bc_thread_state): New.
(struct thread_state): Add bytecode thread state.
Pass the function object and encoded arity, not the other components.
This speeds up several call paths and is necessary for improvements to
come.
* src/bytecode.c (Fbyte_code): Make a new byte code object for
execution. This is slower but performance isn't critical here.
(exec_byte_code): Retrieve components from the passed function.
* src/eval.c (fetch_and_exec_byte_code):
* src/lisp.h (exec_byte_code): Update signature.
* src/bytecode.c (BYTE_CODES, enum byte_code_op, exec_byte_code):
Don't display custom messages in debug mode for Bscan_buffer and
Bset_mark which were removed long ago.
* src/bytecode.c (FETCH2):
Use `|` instead of `+` to combine the bytes forming a 16-bit immediate
argument so that GCC (prior to version 12) recognises the idiom and
generates a 16-bit load. This applies for little-endian machines with
cheap unaligned accesses such as x86[-64], arm64 and power64le.
This 1-character change results in a measurable speed gain on many
kinds of Lisp code, as 16-bit immediates are used by all jump
instructions.
Clang performs this optimisation for both `+` and `|` from version 10.
* src/bytecode.c (exec_byte_code): Inline aref and aset for
vectors and records, since this is important for code that makes heavy
use of arrays and/or objects.
It was implemented but never generated, originally intended for
TCO in the pre-lexbind era (which was semantically dubious anyway).
Removing it speeds up the interpreter because there is no longer any
need for the outermost `count` variable unless checking is enabled.
* lisp/emacs-lisp/bytecomp.el:
* lisp/emacs-lisp/comp.el (comp-limplify-lap-inst):
* src/bytecode.c (BYTE_CODES, exec_byte_code):
Remove definition and implementation of unbind-all, freeing up the opcode
for other purposes.
* src/bytecode.c (exec_byte_code): Perform bytecode unwinding error
check only when building with debugging (NDEBUG not defined, checking
enabled, or BYTE_CODE_SAFE enabled). This improves speed in several
ways.
Since we pass no arguments to a non-lexbind bytecode function, we can
specify its arity as 0 instead of nil and save a test and branch.
* src/bytecode.c (Fbyte_code, exec_byte_code):
* src/eval.c (fetch_and_exec_byte_code, funcall_lambda):
* src/lisp.h:
Change the args_template parameter type to ptrdiff_t, since it is now
always a small integer, in exec_byte_code and
fetch_and_exec_byte_code, all callers adjusted.
Avoid making a copy (in the interpreter C stack frame) of the bytecode
string by making sure it won't be moved by the GC. This is done by
reallocating it to the heap normally only used for large strings,
which isn't compacted.
This requires that we retain an explicit reference to the bytecode
string object (`bytestr`) lest it be GCed away should all other
references vanish during execution. We allocate an extra stack slot
for that, as we already do for the constant vector object.
* src/alloc.c (allocate_string_data): Add `immovable` argument.
(resize_string_data, make_clear_multibyte_string): Use it.
(pin_string): New.
* src/pdumper.c (dump_string): Fix incorrect comment.
Update hash for Lisp_String (only comments changed, not contents).
* src/lread.c (read1):
* src/alloc.c (Fmake_byte_code, purecopy):
* src/bytecode.c (Fbyte_code): Pin bytecode on object creation.
(exec_byte_code): Don't copy bytecode. Retain `bytestr` explicitly.
* src/lisp.h (Lisp_String): Explain special size_byte values.
(string_immovable_p): New.
The function call overhead is nontrivial in comparison to the actual
code which makes this worthwhile.
* src/bytecode.c (exec_byte_code):
Inline code from Fsetcar and Fsetcdr.
Since numeric operations are mostly done on fixnums, this gives a
speed-up for common code.
* src/bytecode.c (exec_byte_code): Inline fixnum comparisons and
operations with fixnum results: =, >, <, <=, >=, -, +, -, *, /, %, max
and min.
Inline parts of the code for function calls to speed up the common
case of calling lexbound byte-code. By eliminating intermediate
functions, this also reduces C stack usage a little.
* src/bytecode.c (exec_byte_code): Inline parts of Ffuncall,
funcall_lambda and fetch_and_exec_byte_code in the Bcall opcode
handler.
* src/eval.c (backtrace_debug_on_exit): Inline and move to lisp.h.
(do_debug_on_call): Make global so that it can be called from
bytecode.c.
(funcall_general): New function, essentially the meat of Ffuncall.
* src/lisp.h (backtrace_debug_on_exit): Moved here from eval.c.
Fchar_syntax did not convert unibyte characters to multibyte when the
current buffer was unibyte, in contrast to `char-syntax` in
byte-compiled code (bug#53260).
* src/bytecode.c (exec_byte_code): Call out to Fchar_syntax;
the dynamic frequency is too low to justify inlining here, and it
did lead to implementations diverging.
* src/syntax.c (Fchar_syntax): Convert non-ASCII unibyte values to
multibyte.
* test/src/syntax-tests.el (syntax-char-syntax): New test.
This simplifies code, and helps performance in some cases (Bug#36597).
* src/lisp.h (hash_rehash_needed_p): Remove. All uses removed.
(hash_rehash_if_needed): Remove. All uses removed.
(struct Lisp_Hash_Table): Remove comment about rehashing hash tables.
* src/pdumper.c (thaw_hash_tables): New function.
(hash_table_thaw): New function.
(hash_table_freeze): New function.
(dump_hash_table): Simplify.
(dump_hash_table_list): New function.
(hash_table_contents): New function.
(Fdump_emacs_portable): Handle hash tables by eager rehashing.
(pdumper_load): Restore hash tables.
(init_pdumper_once): New function.
GCC has removed the -fcheck-pointer bounds option, and the Linux
kernel has also removed support for Intel MPX, so there’s no point
to keeping this debugging option within Emacs.
* src/bytecode.c (BYTE_CODE_THREADED):
* src/lisp.h (DEFINE_LISP_SYMBOL, XSYMBOL, make_lisp_symbol):
Assume __CHKP__ is not defined.
* src/ptr-bounds.h: Remove. All uses of ptr_bounds_clip,
ptr_bounds_copy, ptr_bounds_init, ptr_bounds_set removed.
Check Lisp_Compiled objects better as they’re created,
so that the byte-code interpreter needn’t do the checks
each time it executes them. This improved performance
of ‘make compile-always’ by 1.5% on my platform. Also,
improve the quality of the (still-incomplete) checks, as
this is more practical now that they’re done less often.
* src/alloc.c (make_byte_code): Remove. All uses removed.
(Fmake_byte_code): Put a better (though still incomplete)
check here instead. Simplify by using Fvector instead
of make_uninit_vector followed by memcpy, and by using
XSETPVECTYPE instead of make_byte_code followed by XSETCOMPILED.
* src/bytecode.c (Fbyte_code): Do sanity check and conditional
translation to unibyte here instead of each time the function is
executed.
(exec_byte_code): Omit no-longer-necessary sanity and
unibyte checking. Use SCHARS instead of SBYTES where
either will do, as SCHARS is faster.
* src/eval.c (fetch_and_exec_byte_code): New function.
(funcall_lambda): Use it.
(funcall_lambda, lambda_arity, Ffetch_bytecode):
Omit no-longer-necessary sanity checks.
(Ffetch_bytecode): Add sanity check if actually fetching.
* src/lisp.h (XSETCOMPILED): Remove. All uses removed.
* src/lread.c (read1): Check byte-code objects more thoroughly,
albeit still incompletely, and do translation to unibyte here
instead of each time the function is executed.
(read1): Use XSETPVECYPE instead of make_byte_code.
(read_vector): Omit no-longer-necessary sanity check.
* src/buffer.h (fetch_char_advance, fetch_char_advance_no_check)
(buf_next_char_len, next_char_len, buf_prev_char_len)
(prev_char_len, inc_both, dec_both): New inline functions,
replacing the old character.h macros FETCH_CHAR_ADVANCE,
FETCH_CHAR_ADVANCE_NO_CHECK, BUF_INC_POS, INC_POS, BUF_DEC_POS,
DEC_POS, INC_BOTH, DEC_BOTH respectively. All callers changed.
These new functions all assume buffer primitives and so need
to be here rather than in character.h.
* src/casefiddle.c (make_char_unibyte): New static function,
replacing the old MAKE_CHAR_UNIBYTE macro. All callers changed.
(do_casify_unibyte_string): Use SINGLE_BYTE_CHAR_P instead
of open-coding it.
* src/ccl.c (GET_TRANSLATION_TABLE): New static function,
replacing the old macro of the same name.
* src/character.c (string_char): Omit 2nd arg. 3rd arg can no
longer be NULL. All callers changed.
* src/character.h (SINGLE_BYTE_CHAR_P): Move up.
(MAKE_CHAR_UNIBYTE, MAKE_CHAR_MULTIBYTE, PREV_CHAR_BOUNDARY)
(STRING_CHAR_AND_LENGTH, STRING_CHAR_ADVANCE)
(FETCH_STRING_CHAR_ADVANCE)
(FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE)
(FETCH_STRING_CHAR_ADVANCE_NO_CHECK, FETCH_CHAR_ADVANCE)
(FETCH_CHAR_ADVANCE_NO_CHECK, INC_POS, DEC_POS, INC_BOTH)
(DEC_BOTH, BUF_INC_POS, BUF_DEC_POS): Remove.
(make_char_multibyte): New static function, replacing
the old macro MAKE_CHAR_MULTIBYTE. All callers changed.
(CHAR_STRING_ADVANCE): Remove; all callers changed to use
CHAR_STRING.
(NEXT_CHAR_BOUNDARY): Remove; it was unused.
(raw_prev_char_len): New inline function, replacing the
old PREV_CHAR_BOUNDARY macro. All callers changed.
(string_char_and_length): New inline function, replacing the
old STRING_CHAR_AND_LENGTH macro. All callers changed.
(STRING_CHAR): Rewrite in terms of string_char_and_length.
(string_char_advance): New inline function, replacing the old
STRING_CHAR_ADVANCE macro. All callers changed.
(fetch_string_char_advance): New inline function, replacing the
old FETCH_STRING_CHAR_ADVANCE macro. All callers changed.
(fetch_string_char_as_multibyte_advance): New inline function,
replacing the old FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE macro.
All callers changed.
(fetch_string_char_advance_no_check): New inline function,
replacing the old FETCH_STRING_CHAR_ADVANCE_NO_CHECK macro. All
callers changed.
* src/regex-emacs.c (HEAD_ADDR_VSTRING): Remove; no longer used.
* src/syntax.c (scan_lists): Use dec_bytepos instead of
open-coding it.
* src/xdisp.c (string_char_and_length): Rename from
string_char_and_length to avoid name conflict with new function in
character.h. All callers changed.
They have not been generated by the byte-compiler since Emacs 25.
* lisp/emacs-lisp/bytecomp.el (byte-catch, byte-condition-case):
* src/bytecode.c (BYTE_CODES, exec_byte_code):
Mark as obsolete (since Emacs 25; they were still generated in 24.4).
Following a suggestion by Stefan Monnier in:
https://lists.gnu.org/r/emacs-devel/2019-07/msg00530.html
* doc/lispref/hash.texi (Creating Hash, Defining Hash):
* src/fns.c (Fsxhash_eq, Fsxhash_eql, Fsxhash_equal, Fmake_hash_table):
Don’t insist that hash codes be fixnums, reverting
the recent doc changes to the contrary.
* src/bytecode.c (exec_byte_code): Special-case only the eq case,
as the others aren’t worth tuning now that we treat bignum hashes
like fixnums.
* src/fns.c (hashfn_user_defined): If the hash code is a bignum,
reduce its hash down to a fixnum.
