From: Manolis Tsamis <manolis.tsamis@vrull.eu>
To: gcc-patches@gcc.gnu.org
Cc: Richard Biener <rguenther@suse.de>,
Jiangning Liu <jiangning.liu@amperecomputing.com>,
Philipp Tomsich <philipp.tomsich@vrull.eu>,
Andrew Pinski <quic_apinski@quicinc.com>,
Manolis Tsamis <manolis.tsamis@vrull.eu>
Subject: [PATCH] MATCH: Maybe expand (T)(A + C1) * C2 and (T)(A + C1) * C2 + C3 [PR109393]
Date: Tue, 23 Apr 2024 12:33:36 +0200 [thread overview]
Message-ID: <20240423103336.4024491-1-manolis.tsamis@vrull.eu> (raw)
The original motivation for this pattern was that the following function does
not fold to 'return 1':
int foo(int *a, int j)
{
int k = j - 1;
return a[j - 1] == a[k];
}
The expression ((unsigned long) (X +- C1) * C2) appears frequently as part of
address calculations (e.g. arrays). These patterns help fold and simplify more
expressions.
PR tree-optimization/109393
gcc/ChangeLog:
* match.pd: Add new patterns for ((T)(A +- CST1)) * CST2 and
((T)(A +- CST1)) * CST2 + CST3.
gcc/testsuite/ChangeLog:
* gcc.dg/pr109393.c: New test.
Signed-off-by: Manolis Tsamis <manolis.tsamis@vrull.eu>
---
gcc/match.pd | 30 ++++++++++++++++++++++++++++++
gcc/testsuite/gcc.dg/pr109393.c | 16 ++++++++++++++++
2 files changed, 46 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/pr109393.c
diff --git a/gcc/match.pd b/gcc/match.pd
index d401e7503e6..13c828ba70d 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3650,6 +3650,36 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(plus (convert @0) (op @2 (convert @1))))))
#endif
+/* ((T)(A + CST1)) * CST2 + CST3
+ -> ((T)(A) * CST2) + ((T)CST1 * CST2 + CST3)
+ Where (A + CST1) doesn't need to have a single use. */
+#if GIMPLE
+ (for op (plus minus)
+ (simplify
+ (plus (mult (convert:s (op @0 INTEGER_CST@1)) INTEGER_CST@2) INTEGER_CST@3)
+ (if (TREE_CODE (TREE_TYPE (@0)) == INTEGER_TYPE
+ && TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (@0))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
+ && !TYPE_OVERFLOW_SANITIZED (TREE_TYPE (@0))
+ && TYPE_OVERFLOW_WRAPS (type))
+ (op (mult @2 (convert @0)) (plus (mult @2 (convert @1)) @3)))))
+#endif
+
+/* ((T)(A + CST1)) * CST2 -> ((T)(A) * CST2) + ((T)CST1 * CST2) */
+#if GIMPLE
+ (for op (plus minus)
+ (simplify
+ (mult (convert:s (op:s @0 INTEGER_CST@1)) INTEGER_CST@2)
+ (if (TREE_CODE (TREE_TYPE (@0)) == INTEGER_TYPE
+ && TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (@0))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
+ && !TYPE_OVERFLOW_SANITIZED (TREE_TYPE (@0))
+ && TYPE_OVERFLOW_WRAPS (type))
+ (op (mult @2 (convert @0)) (mult @2 (convert @1))))))
+#endif
+
/* (T)(A) +- (T)(B) -> (T)(A +- B) only when (A +- B) could be simplified
to a simple value. */
(for op (plus minus)
diff --git a/gcc/testsuite/gcc.dg/pr109393.c b/gcc/testsuite/gcc.dg/pr109393.c
new file mode 100644
index 00000000000..e9051273672
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr109393.c
@@ -0,0 +1,16 @@
+/* PR tree-optimization/109393 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-times "return 1;" 2 "optimized" } } */
+
+int foo(int *a, int j)
+{
+ int k = j - 1;
+ return a[j - 1] == a[k];
+}
+
+int bar(int *a, int j)
+{
+ int k = j - 1;
+ return (&a[j + 1] - 2) == &a[k];
+}
--
2.34.1
next reply other threads:[~2024-04-23 10:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-23 10:33 Manolis Tsamis [this message]
2024-05-02 13:00 ` Richard Biener
2024-05-02 13:08 ` Manolis Tsamis
2024-05-02 13:27 ` Richard Biener
2024-05-14 8:57 ` Manolis Tsamis
2024-05-16 8:15 ` Richard Biener
2024-05-17 8:23 ` Manolis Tsamis
2024-05-17 9:22 ` Richard Biener
2024-05-17 11:35 ` Manolis Tsamis
2024-05-17 11:41 ` Richard Biener
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240423103336.4024491-1-manolis.tsamis@vrull.eu \
--to=manolis.tsamis@vrull.eu \
--cc=gcc-patches@gcc.gnu.org \
--cc=jiangning.liu@amperecomputing.com \
--cc=philipp.tomsich@vrull.eu \
--cc=quic_apinski@quicinc.com \
--cc=rguenther@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).