From: "Mattias Engdegård" <mattiase@acm.org>
To: Andrea Corallo <andrea_corallo@yahoo.it>
Cc: Paul Eggert <eggert@cs.ucla.edu>,
Stefan Monnier <monnier@iro.umontreal.ca>,
42147@debbugs.gnu.org
Subject: bug#42147: 28.0.50; pure vs side-effect-free, missing optimizations?
Date: Wed, 1 Jul 2020 18:08:28 +0200 [thread overview]
Message-ID: <0433A879-C98D-4B1A-B85C-A15DA9289099@acm.org> (raw)
In-Reply-To: <3A9CC2A3-8307-47B2-8D80-795C0AF020E1@acm.org>
[-- Attachment #1: Type: text/plain, Size: 320 bytes --]
Andrea, I see nothing directly wrong with your patch, but perhaps our messages went past one another since our lists of proposed pure functions differ.
> More useful would be the ability to constant-fold ash, expt, %, mod and abs for a subset of each respective domain. I can write a patch.
Here is that patch.
[-- Attachment #2: 0001-Constant-fold-mod-ash-expt-and-abs-with-constant-int.patch --]
[-- Type: application/octet-stream, Size: 3537 bytes --]
From aa9ce87268365f766a0d70e6a86bf44067e86b78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mattias=20Engdeg=C3=A5rd?= <mattiase@acm.org>
Date: Wed, 1 Jul 2020 17:44:54 +0200
Subject: [PATCH] Constant-fold %, mod, ash, expt and abs with constant integer
args
To ensure portability, the optimisation is confined to calls where the
result is a portable fixnum. (Bug#42147)
* lisp/emacs-lisp/byte-opt.el (byte-opt--integer-arith)
(byte-optimize-binary-integer-arith, byte-optimize-unary-integer-arith)
(byte-optimize-mod): New functions.
(%, mod, ash, expt, abs): Set byte-optimizer property.
* test/lisp/emacs-lisp/bytecomp-tests.el
(byte-opt-testsuite-arith-data): Add test cases.
---
lisp/emacs-lisp/byte-opt.el | 35 ++++++++++++++++++++++++++
test/lisp/emacs-lisp/bytecomp-tests.el | 12 +++++++++
2 files changed, 47 insertions(+)
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 12bde8faf3..72c68d64b2 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -801,6 +801,34 @@ byte-optimize-divide
form
(cons '/ args)))))
+(defun byte-opt--integer-arith (form)
+ "Constant-fold FORM when args are integers and the result a portable fixnum."
+ (let ((args (cdr form)))
+ (if (memq nil (mapcar #'integerp args))
+ form
+ (let ((res (apply (car form) args)))
+ (if (byte-opt--portable-numberp res)
+ res
+ form)))))
+
+(defun byte-optimize-binary-integer-arith (form)
+ "Constant-fold the binary integer arithmetic call FORM."
+ (if (= (length form) 3)
+ (byte-opt--integer-arith form)
+ form))
+
+(defun byte-optimize-unary-integer-arith (form)
+ "Constant-fold the unary integer arithmetic call FORM."
+ (if (= (length form) 2)
+ (byte-opt--integer-arith form)
+ form))
+
+(defun byte-optimize-mod (form)
+ "Constant-fold the mod-like function call FORM."
+ (if (eql (nth 2 form) 0)
+ form
+ (byte-optimize-binary-integer-arith form)))
+
(defun byte-optimize-binary-predicate (form)
(cond
((or (not (macroexp-const-p (nth 1 form)))
@@ -918,6 +946,13 @@ byte-optimize-concat
(put 'max 'byte-optimizer 'byte-optimize-associative-math)
(put 'min 'byte-optimizer 'byte-optimize-associative-math)
+(put '% 'byte-optimizer 'byte-optimize-mod)
+(put 'mod 'byte-optimizer 'byte-optimize-mod)
+
+(put 'ash 'byte-optimizer 'byte-optimize-binary-integer-arith)
+(put 'expt 'byte-optimizer 'byte-optimize-binary-integer-arith)
+(put 'abs 'byte-optimizer 'byte-optimize-unary-integer-arith)
+
(put '= 'byte-optimizer 'byte-optimize-binary-predicate)
(put 'eq 'byte-optimizer 'byte-optimize-binary-predicate)
(put 'eql 'byte-optimizer 'byte-optimize-equal)
diff --git a/test/lisp/emacs-lisp/bytecomp-tests.el b/test/lisp/emacs-lisp/bytecomp-tests.el
index bfe2d06a61..a96a7c8368 100644
--- a/test/lisp/emacs-lisp/bytecomp-tests.el
+++ b/test/lisp/emacs-lisp/bytecomp-tests.el
@@ -69,6 +69,18 @@ byte-opt-testsuite-arith-data
(let ((a 3) (b 2)) (/ a b 1))
(let ((a 3) (b 2)) (/ (+ a b) 1))
+ ;; More arithmetic constant-folding (bug#42147).
+ (ash 3 10)
+ (ash 3 25)
+ (abs -20)
+ (abs -2305843009213693952)
+ (expt 10 3)
+ (expt 10 20)
+ (% 20 3)
+ (% -20 3)
+ (mod 20 3)
+ (mod -20 3)
+
;; coverage test
(let ((a 3) (b 2) (c 1.0)) (+))
(let ((a 3) (b 2) (c 1.0)) (+ 2))
--
2.21.1 (Apple Git-122.3)
next prev parent reply other threads:[~2020-07-01 16:08 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1583748933.1069307.1593556032592.ref@mail.yahoo.com>
2020-06-30 22:27 ` bug#42147: 28.0.50; pure vs side-effect-free, missing optimizations? Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-06-30 23:14 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-01 12:46 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-01 12:44 ` Mattias Engdegård
2020-07-01 16:08 ` Mattias Engdegård [this message]
2020-07-01 21:31 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-02 10:26 ` Mattias Engdegård
2020-07-02 10:59 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-02 12:46 ` Mattias Engdegård
2020-07-02 13:56 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-02 14:51 ` Mattias Engdegård
2020-07-02 15:32 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-02 15:49 ` Stefan Monnier
2020-07-02 18:01 ` Mattias Engdegård
2020-07-02 18:55 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-02 19:38 ` Stefan Monnier
2020-07-02 20:09 ` Paul Eggert
2020-07-03 9:32 ` Mattias Engdegård
2020-07-03 13:39 ` bug#42147: Hash-consing bignums (was: bug#42147: 28.0.50; pure vs side-effect-free, missing optimizations?) Stefan Monnier
2020-07-02 20:31 ` bug#42147: 28.0.50; pure vs side-effect-free, missing optimizations? Paul Eggert
2020-07-02 21:41 ` Stefan Monnier
2020-07-02 23:16 ` Paul Eggert
2020-07-03 8:32 ` Mattias Engdegård
2020-07-03 13:11 ` Stefan Monnier
2020-07-03 18:35 ` Mattias Engdegård
2020-07-03 18:43 ` Mattias Engdegård
2020-07-03 19:05 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-04 14:58 ` Mattias Engdegård
2020-07-04 15:06 ` Stefan Monnier
2020-07-04 16:13 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-05 13:00 ` Mattias Engdegård
2020-07-05 13:16 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-06 17:20 ` Mattias Engdegård
2020-07-06 21:23 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-07 15:54 ` Mattias Engdegård
2020-07-07 16:24 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-07 16:55 ` Mattias Engdegård
2020-07-07 17:42 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-08 19:14 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-08 21:25 ` Mattias Engdegård
2020-07-08 22:19 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-09 10:20 ` Mattias Engdegård
2020-07-09 12:47 ` Stefan Monnier
2020-07-09 12:57 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-09 14:35 ` Stefan Monnier
2020-07-09 15:19 ` Paul Eggert
2020-07-09 15:37 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-05 15:26 ` Mattias Engdegård
2020-07-03 18:31 ` Paul Eggert
2020-07-03 18:47 ` Mattias Engdegård
2020-07-04 15:57 ` Paul Eggert
2020-07-04 16:15 ` Eli Zaretskii
2020-07-04 16:27 ` Paul Eggert
2020-07-04 16:33 ` Stefan Monnier
2020-07-04 16:44 ` Mattias Engdegård
2020-07-04 17:00 ` Paul Eggert
2020-07-04 18:37 ` Pip Cet
2020-07-04 21:05 ` Stefan Monnier
2020-07-04 22:25 ` Pip Cet
2020-07-05 2:38 ` Eli Zaretskii
2020-07-05 8:28 ` Paul Eggert
2020-07-05 8:39 ` Andreas Schwab
2020-07-05 14:47 ` Eli Zaretskii
2020-07-05 15:30 ` Stefan Monnier
2020-07-06 0:14 ` Paul Eggert
2020-07-05 15:11 ` Stefan Monnier
2020-07-06 0:10 ` Paul Eggert
2020-07-05 9:56 ` Paul Eggert
2020-07-05 10:03 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2020-07-05 23:57 ` Paul Eggert
2020-07-04 19:01 ` Mattias Engdegård
2020-07-04 17:10 ` Eli Zaretskii
2020-07-04 19:26 ` Paul Eggert
2020-07-02 19:09 ` Philipp Stephani
2020-07-03 9:25 ` Mattias Engdegård
2020-07-25 17:09 ` Philipp Stephani
2020-07-25 18:10 ` Stefan Monnier
2020-07-25 20:03 ` Philipp Stephani
2020-07-25 20:07 ` Stefan Monnier
2020-07-25 20:11 ` Philipp Stephani
2020-07-25 21:00 ` Mattias Engdegård
2020-07-25 21:29 ` Stefan Monnier
2020-07-25 21:39 ` Philipp Stephani
2020-07-25 22:27 ` Stefan Monnier
2020-07-29 12:53 ` Philipp Stephani
2020-07-29 14:28 ` Stefan Monnier
2020-07-25 21:54 ` Mattias Engdegård
2020-07-25 22:30 ` Stefan Monnier
2020-07-26 9:05 ` Mattias Engdegård
2020-07-29 16:03 ` Mattias Engdegård
2020-07-29 20:39 ` Stefan Monnier
2020-08-03 15:07 ` Mattias Engdegård
2020-08-10 13:39 ` Philipp Stephani
2020-08-10 22:07 ` Stefan Monnier
2020-08-10 13:42 ` Philipp Stephani
2020-08-10 22:10 ` Stefan Monnier
2020-07-29 13:10 ` Philipp Stephani
2020-07-25 21:09 ` Stefan Monnier
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