https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
Uroš Bizjak changed:
What|Removed |Added
Target Milestone|--- |11.0
Resolution|---
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #16 from CVS Commits ---
The master branch has been updated by Uros Bizjak :
https://gcc.gnu.org/g:8c7bb540803e8bff9998bc86806e8a83acc75370
commit r11-2306-g8c7bb540803e8bff9998bc86806e8a83acc75370
Author: Uros Bizjak
Date: Fri J
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #15 from Uroš Bizjak ---
(In reply to Joseph C. Sible from comment #14)
> I notice this change affects -Os too, even though "lock orq $0,(%rsp)" is 6
> bytes and "mfence" is only 3 bytes.
Yes, we can emit mfence for -Os. I'm testing
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
Joseph C. Sible changed:
What|Removed |Added
CC||josephcsible at gmail dot com
--- Comm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #13 from CVS Commits ---
The master branch has been updated by Uros Bizjak :
https://gcc.gnu.org/g:02363d5fdb862a11e6e65ac5b0d1f5ee0c422dc3
commit r11-2255-g02363d5fdb862a11e6e65ac5b0d1f5ee0c422dc3
Author: Uros Bizjak
Date: Tue J
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #12 from CVS Commits ---
The master branch has been updated by Uros Bizjak :
https://gcc.gnu.org/g:3c5e83d5b32c31b11cf1684bf5d1ab3e7174685c
commit r11-2232-g3c5e83d5b32c31b11cf1684bf5d1ab3e7174685c
Author: Uros Bizjak
Date: Mon J
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
Uroš Bizjak changed:
What|Removed |Added
Attachment #48756|0 |1
is obsolete|
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #10 from Uroš Bizjak ---
Created attachment 48756
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48756&action=edit
Proposed patch
Patch in testing, survives GOMP testcases.
On a related note, the patch uses TARGET_USE_XCHG_FOR
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #9 from Uroš Bizjak ---
(In reply to Jakub Jelinek from comment #8)
> The culprit is the %esp here, that adds the 0x67 prefix to the insn and
> will only work if %rsp is below 4GB.
Ah, indeed... I was in a bit of hurry and didn't no
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
Jakub Jelinek changed:
What|Removed |Added
CC||jakub at gcc dot gnu.org
--- Comment #8
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #7 from Uroš Bizjak ---
Actually, x86_64 (at least my Fedora 32) does not like operations on stack:
Starting program: /sdd/uros/git/gcc/gcc/testsuite/gcc.dg/atomic/a.out
Program received signal SIGSEGV, Segmentation fault.
0x00
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #6 from andysem at mail dot ru ---
Also, I think (%%rsp) can be rather far from the top of the stack if the stack
frame is large. This may mean it's less likely to be in data cache. Having a
dummy variable ensures that it is close to t
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #5 from andysem at mail dot ru ---
> Please also read [1] why we avoid -4(%%esp).
I believe, memcheck would complain because the value at -4(%%rsp) would be
uninitialized. This is unfortunate. The workaround could be to initialize it
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #4 from Uroš Bizjak ---
(In reply to Uroš Bizjak from comment #3)
> How about the following patch:
Surely, mfence_nosse needs to be enabled also for
TARGET_USE_XCHG_FOR_ATOMIC_STORE.
> This will generate "lock orl $0, (%rsp)" instea
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #3 from Uroš Bizjak ---
How about the following patch:
--cut here--
diff --git a/gcc/config/i386/sync.md b/gcc/config/i386/sync.md
index 9ab5456b227..7d9442d45b7 100644
--- a/gcc/config/i386/sync.md
+++ b/gcc/config/i386/sync.md
@@ -
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
--- Comment #2 from andysem at mail dot ru ---
gcc 10.1 only optimizes __atomic_store_n(seq_cst) to xchg, but not the fence.
Also, consider applying the same optimization to __sync_synchronize().
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95750
Andrew Pinski changed:
What|Removed |Added
Depends on||91719
--- Comment #1 from Andrew Pinski
17 matches
Mail list logo
