(condition-case x A (:success B)) should not compile A for-effect even
if the entire form is in for-effect context.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker):
Don't optimise the condition-case body form for effect (potentially
discarding its value) if there is a success handler and a variable.
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-tests--test-cases):
Add test cases.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-if):
Remove explicit clauses purposing to simplify
(if X nil t) -> (not X)
(if X t nil) -> (not (not X))
but never did so because of a coding mistake (eq instead of equal),
found by a recently added warning. They weren't actually needed
thanks to the optimiser's fixpoint iteration: we eventually get the
same results through
(if X nil t) -> (if (not X) t nil) -> (if (not X) t) -> (not X)
(if X t nil) -> (if X t) -> (not (not X))
* lisp/emacs-lisp/byte-opt.el (byte-optimize-if):
Remove explicit clauses purposing to simplify
(if X nil t) -> (not X)
(if X t nil) -> (not (not X))
but never did so because of a coding mistake (eq instead of equal),
found by a recently added warning. They weren't actually needed
thanks to the optimiser's fixpoint iteration: we eventually get the
same results through
(if X nil t) -> (if (not X) t nil) -> (if (not X) t) -> (not X)
(if X t nil) -> (if X t) -> (not (not X))
* lisp/emacs-lisp/byte-opt.el (byte-optimize-if):
Remove explicit clauses purposing to simplify
(if X nil t) -> (not X)
(if X t nil) -> (not (not X))
but never did so because of a coding mistake (eq instead of equal),
found by a recently added warning. They weren't actually needed
thanks to the optimiser's fixpoint iteration: we eventually get the
same results through
(if X nil t) -> (if (not X) t nil) -> (if (not X) t) -> (not X)
(if X t nil) -> (if X t) -> (not (not X))
* lisp/emacs-lisp/byte-opt.el (byte-opt--bool-value-form):
`set` is boolean identity in its second argument.
(byte-compile-trueconstp): `set-marker` is always true.
Only perform the rewrite
(set 'VAR X) -> (setq VAR X)
for dynamic variables, as `set` isn't supposed to affect
lexical vars (and never does so when interpreted).
* lisp/emacs-lisp/byte-opt.el (byte-optimize-set):
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-tests--xx): New.
(bytecomp-tests--test-cases): Add test cases.
* test/lisp/emacs-lisp/bytecomp-resources/warn-variable-set-nonvariable.el:
Remove obsolete test.
For a switch op to be generated, comparisons must be made using `eq`,
`eql` or `equal`, not `=`.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-lapcode):
* lisp/files.el (file-modes-char-to-who, file-modes-char-to-right):
* lisp/international/titdic-cnv.el (tit-process-header):
* lisp/language/ethio-util.el (ethio-input-special-character)
(ethio-fidel-to-tex-buffer):
* lisp/language/lao.el (consonant):
Use `eq` or `eql` instead of `=`.
In these cases either `eq` or `eql` would do and the choice does not
affect the resulting code. We compare numbers with `eql` and
characters with `eq` as a matter of style.
* lisp/emacs-lisp/byte-opt.el (byte-opt--bool-value-form):
Recognise boolean identity in aset, put, function-put and puthash.
* lisp/emacs-lisp/byte-opt.el (byte-compile-trueconstp):
Mark more functins as non-nil-returning, including the new
pos-bol and pos-eol.
* lisp/emacs-lisp/byte-opt.el (side-effect-free-fns):
Mark pos-bol and pos-eol as side-effect-free.
This change was partially generated and mechanically cross-validated
with function type information from comp-known-type-specifiers in
comp.el.
* lisp/emacs-lisp/byte-opt.el (byte-compile-trueconstp):
Extend list of functions and fix a typo (logxor).
* lisp/emacs-lisp/byte-opt.el (byte-optimize-and, byte-optimize-or):
Rewrite. Avoid branching on arguments statically known to be true or
false, and hoist code out to an unconditional prefix when possible.
Recognise some more special cases:
(if X nil t) -> (not X)
(if X t) -> (not (not X))
(if X t nil) -> (not (not X))
(if VAR VAR X...) -> (or VAR (progn X...))
* lisp/emacs-lisp/byte-opt.el (byte-opt-negate): New.
(byte-optimize-if): Add transformations above and refactor.
(byte-optimize-while): Better static nil-detection.
* lisp/emacs-lisp/byte-opt.el (byte-opt--bool-value-form): New.
(byte-compile-trueconstp, byte-compile-nilconstp): Determine a static
nil or non-nil result in more cases. These functions have grown and
are no longer defsubst.
Extend the set of eligible opcodes for certain peephole
transformations, which then provide further optimisation
opportunities.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-lapcode):
Optimise empty save-current-buffer in the same way as we already
do for save-excursion and save-restriction. This is safe
because (save-current-buffer) is a no-op.
(byte-compile-side-effect-and-error-free-ops): Add list3, list4 and
listN. These were all apparent oversights as list1 and list2 were
already included.
(byte-after-unbind-ops): Add stack-ref, stack-set, discard, list3,
list4 and listN. Stack manipulation is safe because unbind cannot
read or modify stack entries.
This variable and related functions have been obsolete since 23.1.
The last things to depend on this (fast-lock.el and lazy-lock.el) were
recently removed.
* src/dispextern.h (struct it): Delete field
'redisplay_end_trigger_charpos'.
* src/window.c (Fwindow_redisplay_end_trigger)
(Fset_window_redisplay_end_trigger): Delete defuns and corresponding
defsubrs for functions obsolete since 23.1.
* src/window.h (wset_redisplay_end_trigger): Delete function.
(GCALIGNED_STRUCT): Delete 'redisplay_end_trigger'.
* src/xdisp.c (run_redisplay_end_trigger_hook): Delete function.
(syms_of_xdisp) <redisplay_end_trigger_functions>: Delete
variable obsolete since 23.1.
(init_iterator, next_element_from_buffer): Don't run or set above
deleted hook variable.
* lisp/subr.el: Delete obsoletion definitions for above deleted
defuns and variable.
* doc/lispref/hooks.texi (Standard Hooks):
* lisp/emacs-lisp/byte-opt.el (side-effect-free-fns):
* lisp/loadhist.el (unload-feature-special-hooks): Don't mention
above deleted variable.
* admin/coccinelle/window.cocci: Adjust for above changes.
This optimisation is already done in the code generator but performing
it at this earlier stage is a useful normalising step that uncovers
more opportunities.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-list): New.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker):
Turn functions into nil when compiled for-effect since they have no
side-effects on their own. This may enable further improvements such
as the elimination of variable bindings.
`unwind-protect` forms can be treated as plain function call at this
point. In particular, their unwind function argument should be
not optimised for effect since it's a function.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker)
(byte-optimize-let-form, byte-optimize-letX):
* lisp/emacs-lisp/bytecomp.el (byte-compile-unwind-protect):
Simplify source optimisation and codegen code that can now rely on
normalised let/let* and unwind-protect forms.
Early normalisation of setq during macroexpand-all allows later
stages, cconv, byte-opt and codegen, to be simplified and duplicated
checks to be eliminated.
* lisp/emacs-lisp/macroexp.el (macroexp--expand-all):
Normalise all setq forms to a sequence of (setq VAR EXPR).
Emit warnings if necessary.
* lisp/emacs-lisp/cconv.el (cconv-convert, cconv-analyze-form):
* lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker):
* lisp/emacs-lisp/bytecomp.el (byte-compile-setq):
Simplify.
* test/lisp/emacs-lisp/bytecomp-tests.el: Adapt and add tests.
* test/lisp/emacs-lisp/bytecomp-resources/warn-variable-setq-nonvariable.el;
* test/lisp/emacs-lisp/bytecomp-resources/warn-variable-setq-odd.el:
New files.
These are symbols with position from source code, which should not be replaced
by bare symbols in, e.g., optimization functions.
* lisp/Makefile.in: (BYTE_COMPILE_FLAGS, compile-first case): Set
max-specpdl-size to 5000 for the benefit of lisp/emacs-lisp/comp.el.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker)
(byte-optimize--rename-var, byte-optimize-if, byte-optimize-letX)
* lisp/emacs-lisp/bytecomp.el (byte-compile-recurse-toplevel)
(byte-compile-lambda)
* lisp/emacs-lisp/cconv.el (cconv-convert)
* lisp/emacs-lisp/macroexp.el (macroexp--expand-all): Preserve, e.g., (car
form) in the byte compiler, when this form's car is a symbol with position of
a special form, rather than replacing the symbol with a bare symbol, e.g.
'cond.
Since string-lessp has its own byte-op, using it is much faster than
calling string-greaterp even with the need to bind a temporary
variable.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-string-greaterp): New.
(string-greaterp, string>): Set byte-optimizer.
* lisp/emacs-lisp/byte-opt.el (side-effect-free-fns, pure-fns):
Mark base64-decode-string, base64-encode-string and
base64url-encode-string as pure and side-effect-free.
* lisp/emacs-lisp/byte-opt.el (byte-optimize--substitutable-p):
Treat (internal-get-closed-var N) as constants for propagation
purposes, because that is effectively what such forms will be compiled
to. This allows for the elimination of some lexical variables.
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-tests--test-cases):
Add test case.
