From: <apinski@marvell.com>
To: <gcc-patches@gcc.gnu.org>
Cc: Andrew Pinski <apinski@marvell.com>
Subject: [PATCHv2] Add a couple of A?CST1:CST2 match and simplify optimizations
Date: Sun, 23 May 2021 02:41:03 -0700 [thread overview]
Message-ID: <1621762863-26665-1-git-send-email-apinski@marvell.com> (raw)
From: Andrew Pinski <apinski@marvell.com>
Instead of some of the more manual optimizations inside phi-opt,
it would be good idea to do a lot of the heavy lifting inside match
and simplify instead. In the process, this moves the three simple
A?CST1:CST2 (where CST1 or CST2 is zero) simplifications.
OK? Boostrapped and tested on x86_64-linux-gnu with no regressions.
Differences from V1:
* Use bit_xor 1 instead of bit_not to fix the problem with boolean types
which are not 1 bit precision.
Thanks,
Andrew Pinski
gcc:
* match.pd (A?CST1:CST2): Add simplifcations for A?0:+-1, A?+-1:0,
A?POW2:0 and A?0:POW2.
---
gcc/match.pd | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/gcc/match.pd b/gcc/match.pd
index 1fc6b7b1557..ad6b057c56d 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3711,6 +3711,47 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (integer_all_onesp (@1) && integer_zerop (@2))
@0))))
+/* A few simplifications of "a ? CST1 : CST2". */
+/* NOTE: Only do this on gimple as the if-chain-to-switch
+ optimization depends on the gimple to have if statements in it. */
+#if GIMPLE
+(simplify
+ (cond @0 INTEGER_CST@1 INTEGER_CST@2)
+ (switch
+ (if (integer_zerop (@2))
+ (switch
+ /* a ? 1 : 0 -> a if 0 and 1 are integral types. */
+ (if (integer_onep (@1))
+ (convert (convert:boolean_type_node @0)))
+ /* a ? -1 : 0 -> -a. */
+ (if (integer_all_onesp (@1))
+ (negate (convert (convert:boolean_type_node @0))))
+ /* a ? powerof2cst : 0 -> a << (log2(powerof2cst)) */
+ (if (!POINTER_TYPE_P (type) && integer_pow2p (@1))
+ (with {
+ tree shift = build_int_cst (integer_type_node, tree_log2 (@1));
+ }
+ (lshift (convert (convert:boolean_type_node @0)) { shift; })))))
+ (if (integer_zerop (@1))
+ (with {
+ tree booltrue = constant_boolean_node (true, boolean_type_node);
+ }
+ (switch
+ /* a ? 0 : 1 -> !a. */
+ (if (integer_onep (@2))
+ (convert (bit_xor (convert:boolean_type_node @0) { booltrue; } )))
+ /* a ? -1 : 0 -> -(!a). */
+ (if (integer_all_onesp (@2))
+ (negate (convert (bit_xor (convert:boolean_type_node @0) { booltrue; } ))))
+ /* a ? powerof2cst : 0 -> (!a) << (log2(powerof2cst)) */
+ (if (!POINTER_TYPE_P (type) && integer_pow2p (@2))
+ (with {
+ tree shift = build_int_cst (integer_type_node, tree_log2 (@2));
+ }
+ (lshift (convert (bit_xor (convert:boolean_type_node @0) { booltrue; } ))
+ { shift; }))))))))
+#endif
+
/* Simplification moved from fold_cond_expr_with_comparison. It may also
be extended. */
/* This pattern implements two kinds simplification:
--
2.17.1
next reply other threads:[~2021-05-23 9:41 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-23 9:41 apinski [this message]
2021-05-25 14:22 ` Richard Biener
2021-05-26 8:28 ` Bernd Edlinger
2021-05-26 9:01 ` Andrew Pinski
2021-05-26 11:07 ` Andrew Pinski
2021-05-26 11:27 ` Richard Biener
2021-05-26 11:37 ` Andrew Pinski
2021-05-26 12:05 ` Richard Biener
2021-05-26 16:59 ` Andrew MacLeod
2021-05-26 17:03 ` Bernd Edlinger
2021-05-26 17:07 ` Bernd Edlinger
2021-05-26 17:15 ` Andrew MacLeod
2021-05-26 16:54 ` Aldy Hernandez
2021-05-26 17:29 ` Andrew MacLeod
2021-05-28 4:53 ` Jeff Law
2021-05-28 7:16 ` 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=1621762863-26665-1-git-send-email-apinski@marvell.com \
--to=apinski@marvell.com \
--cc=gcc-patches@gcc.gnu.org \
/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).