public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Tamar Christina <tamar.christina@arm.com>
To: gcc-patches@gcc.gnu.org
Cc: nd@arm.com, rguenther@suse.de, jlaw@ventanamicro.com
Subject: [PATCH 4/19]middle-end: Fix scale_loop_frequencies segfault on multiple-exits
Date: Wed, 28 Jun 2023 14:43:33 +0100	[thread overview]
Message-ID: <ZJw5BcegL6zob2rC@arm.com> (raw)
In-Reply-To: <patch-17494-tamar@arm.com>

[-- Attachment #1: Type: text/plain, Size: 2237 bytes --]

Hi All,

There's an existing bug in loop frequency scaling where the if statement checks
to see if there's a single exit, and records an dump file note but then
continues.

It then tries to access the null pointer, which of course fails.

For multiple loop exists it's not really clear how to scale the exit
probablities as it's really unknown which exit is most probably.

For that reason I ignore the exit edges during scaling but still adjust the
loop body.

Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.

Ok for master?

Thanks,
Tamar

gcc/ChangeLog:

	* cfgloopmanip.cc (scale_loop_frequencies): Fix typo.
	(scale_loop_profile): Don't access null pointer.

--- inline copy of patch -- 
diff --git a/gcc/cfgloopmanip.cc b/gcc/cfgloopmanip.cc
index 6e09dcbb0b1864bc64ffd570a4b923f50c3819b5..b10ef3d2be82902ccd74e52a4318217b2db13bcb 100644
--- a/gcc/cfgloopmanip.cc
+++ b/gcc/cfgloopmanip.cc
@@ -501,7 +501,7 @@ scale_loop_frequencies (class loop *loop, profile_probability p)
 /* Scale profile in LOOP by P.
    If ITERATION_BOUND is non-zero, scale even further if loop is predicted
    to iterate too many times.
-   Before caling this function, preheader block profile should be already
+   Before calling this function, preheader block profile should be already
    scaled to final count.  This is necessary because loop iterations are
    determined by comparing header edge count to latch ege count and thus
    they need to be scaled synchronously.  */
@@ -597,14 +597,14 @@ scale_loop_profile (class loop *loop, profile_probability p,
       /* If latch exists, change its count, since we changed
 	 probability of exit.  Theoretically we should update everything from
 	 source of exit edge to latch, but for vectorizer this is enough.  */
-      if (loop->latch && loop->latch != e->src)
+      if (e && loop->latch && loop->latch != e->src)
 	loop->latch->count += count_delta;
 
       /* Scale the probabilities.  */
       scale_loop_frequencies (loop, p);
 
       /* Change latch's count back.  */
-      if (loop->latch && loop->latch != e->src)
+      if (e && loop->latch && loop->latch != e->src)
 	loop->latch->count -= count_delta;
 
       if (dump_file && (dump_flags & TDF_DETAILS))




-- 

[-- Attachment #2: rb17498.patch --]
[-- Type: text/plain, Size: 1523 bytes --]

diff --git a/gcc/cfgloopmanip.cc b/gcc/cfgloopmanip.cc
index 6e09dcbb0b1864bc64ffd570a4b923f50c3819b5..b10ef3d2be82902ccd74e52a4318217b2db13bcb 100644
--- a/gcc/cfgloopmanip.cc
+++ b/gcc/cfgloopmanip.cc
@@ -501,7 +501,7 @@ scale_loop_frequencies (class loop *loop, profile_probability p)
 /* Scale profile in LOOP by P.
    If ITERATION_BOUND is non-zero, scale even further if loop is predicted
    to iterate too many times.
-   Before caling this function, preheader block profile should be already
+   Before calling this function, preheader block profile should be already
    scaled to final count.  This is necessary because loop iterations are
    determined by comparing header edge count to latch ege count and thus
    they need to be scaled synchronously.  */
@@ -597,14 +597,14 @@ scale_loop_profile (class loop *loop, profile_probability p,
       /* If latch exists, change its count, since we changed
 	 probability of exit.  Theoretically we should update everything from
 	 source of exit edge to latch, but for vectorizer this is enough.  */
-      if (loop->latch && loop->latch != e->src)
+      if (e && loop->latch && loop->latch != e->src)
 	loop->latch->count += count_delta;
 
       /* Scale the probabilities.  */
       scale_loop_frequencies (loop, p);
 
       /* Change latch's count back.  */
-      if (loop->latch && loop->latch != e->src)
+      if (e && loop->latch && loop->latch != e->src)
 	loop->latch->count -= count_delta;
 
       if (dump_file && (dump_flags & TDF_DETAILS))




  parent reply	other threads:[~2023-06-28 13:44 UTC|newest]

Thread overview: 200+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-28 13:40 [PATCH v5 0/19] Support early break/return auto-vectorization Tamar Christina
2023-06-28 13:41 ` [PATCH 1/19]middle-end ifcvt: Support bitfield lowering of multiple-exit loops Tamar Christina
2023-07-04 11:29   ` Richard Biener
2023-06-28 13:41 ` [PATCH 2/19][front-end] C/C++ front-end: add pragma GCC novector Tamar Christina
2023-06-29 22:17   ` Jason Merrill
2023-06-30 16:18     ` Tamar Christina
2023-06-30 16:44       ` Jason Merrill
2023-06-28 13:42 ` [PATCH 3/19]middle-end clean up vect testsuite using pragma novector Tamar Christina
2023-06-28 13:54   ` Tamar Christina
2023-07-04 11:31   ` Richard Biener
2023-06-28 13:43 ` Tamar Christina [this message]
2023-07-04 11:52   ` [PATCH 4/19]middle-end: Fix scale_loop_frequencies segfault on multiple-exits Richard Biener
2023-07-04 14:57     ` Jan Hubicka
2023-07-06 14:34       ` Jan Hubicka
2023-07-07  5:59         ` Richard Biener
2023-07-07 12:20           ` Jan Hubicka
2023-07-07 12:27             ` Tamar Christina
2023-07-07 14:10               ` Jan Hubicka
2023-07-10  7:07             ` Richard Biener
2023-07-10  8:33               ` Jan Hubicka
2023-07-10  9:24                 ` Richard Biener
2023-07-10  9:23               ` Jan Hubicka
2023-07-10  9:29                 ` Richard Biener
2023-07-11  9:28                   ` Jan Hubicka
2023-07-11 10:31                     ` Richard Biener
2023-07-11 12:40                       ` Jan Hubicka
2023-07-11 13:04                         ` Richard Biener
2023-06-28 13:43 ` [PATCH 5/19]middle-end: Enable bit-field vectorization to work correctly when we're vectoring inside conds Tamar Christina
2023-07-04 12:05   ` Richard Biener
2023-07-10 15:32     ` Tamar Christina
2023-07-11 11:03       ` Richard Biener
2023-06-28 13:44 ` [PATCH 6/19]middle-end: Don't enter piecewise expansion if VF is not constant Tamar Christina
2023-07-04 12:10   ` Richard Biener
2023-07-06 10:37     ` Tamar Christina
2023-07-06 10:51       ` Richard Biener
2023-06-28 13:44 ` [PATCH 7/19]middle-end: Refactor vectorizer loop conditionals and separate out IV to new variables Tamar Christina
2023-07-13 11:32   ` Richard Biener
2023-07-13 11:54     ` Tamar Christina
2023-07-13 12:10       ` Richard Biener
2023-06-28 13:45 ` [PATCH 8/19]middle-end: updated niters analysis to handle multiple exits Tamar Christina
2023-07-13 11:49   ` Richard Biener
2023-07-13 12:03     ` Tamar Christina
2023-07-14  9:09     ` Richard Biener
2023-06-28 13:45 ` [PATCH 9/19]AArch64 middle-end: refactor vectorizable_comparison to make the main body re-usable Tamar Christina
2023-06-28 13:55   ` [PATCH 9/19] " Tamar Christina
2023-07-13 16:23     ` Richard Biener
2023-06-28 13:46 ` [PATCH 10/19]middle-end: implement vectorizable_early_break Tamar Christina
2023-06-28 13:46 ` [PATCH 11/19]middle-end: implement code motion for early break Tamar Christina
2023-06-28 13:47 ` [PATCH 12/19]middle-end: implement loop peeling and IV updates " Tamar Christina
2023-07-13 17:31   ` Richard Biener
2023-07-13 19:05     ` Tamar Christina
2023-07-14 13:34       ` Richard Biener
2023-07-17 10:56         ` Tamar Christina
2023-07-17 12:48           ` Richard Biener
2023-08-18 11:35         ` Tamar Christina
2023-08-18 12:53           ` Richard Biener
2023-08-18 13:12             ` Tamar Christina
2023-08-18 13:15               ` Richard Biener
2023-10-23 20:21         ` Tamar Christina
2023-06-28 13:47 ` [PATCH 13/19]middle-end testsuite: un-xfail TSVC loops that check for exit control flow vectorization Tamar Christina
2023-06-28 13:47 ` [PATCH 14/19]middle-end testsuite: Add new tests for early break vectorization Tamar Christina
2023-06-28 13:48 ` [PATCH 15/19]AArch64: Add implementation for vector cbranch for Advanced SIMD Tamar Christina
2023-06-28 13:48 ` [PATCH 16/19]AArch64 Add optimization for vector != cbranch fed into compare with 0 " Tamar Christina
2023-06-28 13:48 ` [PATCH 17/19]AArch64 Add optimization for vector cbranch combining SVE and " Tamar Christina
2023-06-28 13:49 ` [PATCH 18/19]Arm: Add Advanced SIMD cbranch implementation Tamar Christina
2023-06-28 13:50 ` [PATCH 19/19]Arm: Add MVE " Tamar Christina
     [not found] ` <MW5PR11MB5908414D8B2AB0580A888ECAA924A@MW5PR11MB5908.namprd11.prod.outlook.com>
2023-06-28 14:49   ` FW: [PATCH v5 0/19] Support early break/return auto-vectorization 钟居哲
2023-06-28 16:00     ` Tamar Christina
2023-11-06  7:36 ` [PATCH v6 0/21]middle-end: " Tamar Christina
2023-11-06  7:37 ` [PATCH 1/21]middle-end testsuite: Add more pragma novector to new tests Tamar Christina
2023-11-07  9:46   ` Richard Biener
2023-11-06  7:37 ` [PATCH 2/21]middle-end testsuite: Add tests for early break vectorization Tamar Christina
2023-11-07  9:52   ` Richard Biener
2023-11-16 10:53     ` Richard Biener
2023-11-06  7:37 ` [PATCH 3/21]middle-end: Implement code motion and dependency analysis for early breaks Tamar Christina
2023-11-07 10:53   ` Richard Biener
2023-11-07 11:34     ` Tamar Christina
2023-11-07 14:23       ` Richard Biener
2023-12-19 10:11         ` Tamar Christina
2023-12-19 14:05           ` Richard Biener
2023-12-20 10:51             ` Tamar Christina
2023-12-20 12:24               ` Richard Biener
2023-11-06  7:38 ` [PATCH 4/21]middle-end: update loop peeling code to maintain LCSSA form " Tamar Christina
2023-11-15  0:00   ` Tamar Christina
2023-11-15 12:40     ` Richard Biener
2023-11-20 21:51       ` Tamar Christina
2023-11-24 10:16         ` Tamar Christina
2023-11-24 12:38           ` Richard Biener
2023-11-06  7:38 ` [PATCH 5/21]middle-end: update vectorizer's control update to support picking an exit other than loop latch Tamar Christina
2023-11-07 15:04   ` Richard Biener
2023-11-07 23:10     ` Tamar Christina
2023-11-13 20:11     ` Tamar Christina
2023-11-14  7:56       ` Richard Biener
2023-11-14  8:07         ` Tamar Christina
2023-11-14 23:59           ` Tamar Christina
2023-11-15 12:14             ` Richard Biener
2023-11-06  7:38 ` [PATCH 6/21]middle-end: support multiple exits in loop versioning Tamar Christina
2023-11-07 14:54   ` Richard Biener
2023-11-06  7:39 ` [PATCH 7/21]middle-end: update IV update code to support early breaks and arbitrary exits Tamar Christina
2023-11-15  0:03   ` Tamar Christina
2023-11-15 13:01     ` Richard Biener
2023-11-15 13:09       ` Tamar Christina
2023-11-15 13:22         ` Richard Biener
2023-11-15 14:14           ` Tamar Christina
2023-11-16 10:40             ` Richard Biener
2023-11-16 11:08               ` Tamar Christina
2023-11-16 11:27                 ` Richard Biener
2023-11-16 12:01                   ` Tamar Christina
2023-11-16 12:30                     ` Richard Biener
2023-11-16 13:22                       ` Tamar Christina
2023-11-16 13:35                         ` Richard Biener
2023-11-16 14:14                           ` Tamar Christina
2023-11-16 14:17                             ` Richard Biener
2023-11-16 15:19                               ` Tamar Christina
2023-11-16 18:41                                 ` Tamar Christina
2023-11-17 10:40                                   ` Tamar Christina
2023-11-17 12:13                                     ` Richard Biener
2023-11-20 21:54                                       ` Tamar Christina
2023-11-24 10:18                                         ` Tamar Christina
2023-11-24 12:41                                           ` Richard Biener
2023-11-06  7:39 ` [PATCH 8/21]middle-end: update vectorizable_live_reduction with support for multiple exits and different exits Tamar Christina
2023-11-15  0:05   ` Tamar Christina
2023-11-15 13:41     ` Richard Biener
2023-11-15 14:26       ` Tamar Christina
2023-11-16 11:16         ` Richard Biener
2023-11-20 21:57           ` Tamar Christina
2023-11-24 10:20             ` Tamar Christina
2023-11-24 13:23               ` Richard Biener
2023-11-27 22:47                 ` Tamar Christina
2023-11-29 13:28                   ` Richard Biener
2023-11-29 21:22                     ` Tamar Christina
2023-11-30 13:23                       ` Richard Biener
2023-12-06  4:21                         ` Tamar Christina
2023-12-06  9:33                           ` Richard Biener
2023-11-06  7:39 ` [PATCH 9/21]middle-end: implement vectorizable_early_exit for codegen of exit code Tamar Christina
2023-11-27 22:49   ` Tamar Christina
2023-11-29 13:50     ` Richard Biener
2023-12-06  4:37       ` Tamar Christina
2023-12-06  9:37         ` Richard Biener
2023-12-08  8:58           ` Tamar Christina
2023-12-08 10:28             ` Richard Biener
2023-12-08 13:45               ` Tamar Christina
2023-12-08 13:59                 ` Richard Biener
2023-12-08 15:01                   ` Tamar Christina
2023-12-11  7:09                   ` Tamar Christina
2023-12-11  9:36                     ` Richard Biener
2023-12-11 23:12                       ` Tamar Christina
2023-12-12 10:10                         ` Richard Biener
2023-12-12 10:27                           ` Tamar Christina
2023-12-12 10:59                           ` Richard Sandiford
2023-12-12 11:30                             ` Richard Biener
2023-12-13 14:13                               ` Tamar Christina
2023-12-14 13:12                                 ` Richard Biener
2023-12-14 18:44                                   ` Tamar Christina
2023-11-06  7:39 ` [PATCH 10/21]middle-end: implement relevancy analysis support for control flow Tamar Christina
2023-11-27 22:49   ` Tamar Christina
2023-11-29 14:47     ` Richard Biener
2023-12-06  4:10       ` Tamar Christina
2023-12-06  9:44         ` Richard Biener
2023-11-06  7:40 ` [PATCH 11/21]middle-end: wire through peeling changes and dominator updates after guard edge split Tamar Christina
2023-11-06  7:40 ` [PATCH 12/21]middle-end: Add remaining changes to peeling and vectorizer to support early breaks Tamar Christina
2023-11-27 22:48   ` Tamar Christina
2023-12-06  8:31   ` Richard Biener
2023-12-06  9:10     ` Tamar Christina
2023-12-06  9:27       ` Richard Biener
2023-11-06  7:40 ` [PATCH 13/21]middle-end: Update loop form analysis to support early break Tamar Christina
2023-11-27 22:48   ` Tamar Christina
2023-12-06  4:00     ` Tamar Christina
2023-12-06  8:18   ` Richard Biener
2023-12-06  8:52     ` Tamar Christina
2023-12-06  9:15       ` Richard Biener
2023-12-06  9:29         ` Tamar Christina
2023-11-06  7:41 ` [PATCH 14/21]middle-end: Change loop analysis from looking at at number of BB to actual cfg Tamar Christina
2023-11-06 14:44   ` Richard Biener
2023-11-06  7:41 ` [PATCH 15/21]middle-end: [RFC] conditionally support forcing final edge for debugging Tamar Christina
2023-12-09 10:38   ` Richard Sandiford
2023-12-11  7:38     ` Richard Biener
2023-12-11  8:49       ` Tamar Christina
2023-12-11  9:00         ` Richard Biener
2023-11-06  7:41 ` [PATCH 16/21]middle-end testsuite: un-xfail TSVC loops that check for exit control flow vectorization Tamar Christina
2023-11-06  7:41 ` [PATCH 17/21]AArch64: Add implementation for vector cbranch for Advanced SIMD Tamar Christina
2023-11-28 16:37   ` Richard Sandiford
2023-11-28 17:55     ` Richard Sandiford
2023-12-06 16:25       ` Tamar Christina
2023-12-07  0:56         ` Richard Sandiford
2023-12-14 18:40           ` Tamar Christina
2023-12-14 19:34             ` Richard Sandiford
2023-11-06  7:42 ` [PATCH 18/21]AArch64: Add optimization for vector != cbranch fed into compare with 0 " Tamar Christina
2023-11-06  7:42 ` [PATCH 19/21]AArch64: Add optimization for vector cbranch combining SVE and " Tamar Christina
2023-11-06  7:42 ` [PATCH 20/21]Arm: Add Advanced SIMD cbranch implementation Tamar Christina
2023-11-27 12:48   ` Kyrylo Tkachov
2023-11-06  7:43 ` [PATCH 21/21]Arm: Add MVE " Tamar Christina
2023-11-27 12:47   ` Kyrylo Tkachov
2023-11-06 14:25 ` [PATCH v6 0/21]middle-end: Support early break/return auto-vectorization Richard Biener
2023-11-06 15:17   ` Tamar Christina
2023-11-07  9:42     ` Richard Biener
2023-11-07 10:47       ` Tamar Christina
2023-11-07 13:58         ` Richard Biener
2023-11-27 18:30           ` Richard Sandiford
2023-11-28  8:11             ` 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=ZJw5BcegL6zob2rC@arm.com \
    --to=tamar.christina@arm.com \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=jlaw@ventanamicro.com \
    --cc=nd@arm.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).