[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 Jackie Rosen changed: What|Removed |Added CC||jackie.rosen at hushmail dot com --- Comment #14 from Jackie Rosen --- *** Bug 260998 has been marked as a duplicate of this bug. *** Seen from the domain http://volichat.com Page where seen: http://volichat.com/adult-chat-rooms Marked for reference. Resolved as fixed @bugzilla.
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 Uros Bizjak changed: What|Removed |Added Status|ASSIGNED|RESOLVED URL||http://gcc.gnu.org/ml/gcc-p ||atches/2013-01/msg00870.htm ||l Resolution||FIXED --- Comment #13 from Uros Bizjak 2013-01-17 22:53:58 UTC --- Fixed.
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #12 from uros at gcc dot gnu.org 2013-01-17 22:51:07 UTC --- Author: uros Date: Thu Jan 17 22:51:00 2013 New Revision: 195283 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195283 Log: Backport from mainline 2012-01-17 Uros Bizjak PR target/55981 * config/i386/sync.md (atomic_store): Generate SWImode store through atomic_store_1. (atomic_store_1): Macroize insn using SWI mode iterator. testsuite/ChangeLog: Backport from mainline 2012-01-17 Uros Bizjak PR target/55981 * gcc.target/pr55981.c: New test. Added: branches/gcc-4_7-branch/gcc/testsuite/gcc.target/pr55981.c Modified: branches/gcc-4_7-branch/gcc/ChangeLog branches/gcc-4_7-branch/gcc/config/i386/sync.md branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #11 from uros at gcc dot gnu.org 2013-01-17 16:25:04 UTC --- Author: uros Date: Thu Jan 17 16:24:54 2013 New Revision: 195273 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195273 Log: PR target/55981 * config/i386/sync.md (atomic_store): Always generate SWImode store through atomic_store_1. (atomic_store_1): Macroize insn using SWI mode iterator. testsuite/ChangeLog: PR target/55981 * gcc.target/pr55981.c: New test. Added: trunk/gcc/testsuite/gcc.target/i386/pr55981.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/sync.md trunk/gcc/testsuite/ChangeLog
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #10 from Uros Bizjak 2013-01-15 20:01:41 UTC --- (In reply to comment #9) > (In reply to comment #4) > > (In reply to comment #2) > > > Btw, the same happens if atomic is replaced with "volatile unsigned long > > > y" - > > > which does not violate the standard, but may be considered undesirable by > > > some. > > > I don't have a strong opinion about this. > > > > This really does need to be fixed in the "volatile unsigned long y" case, or > > device drivers storing constants to device registers will break. So please > > fix > > this for volatiles as well as atomics. > > Please open a new PR for this. It looks to me that volatiles should not be allowed as offsetable operands, but let's discuss this in a separate PR.
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #9 from Uros Bizjak 2013-01-15 19:39:20 UTC --- (In reply to comment #4) > (In reply to comment #2) > > Btw, the same happens if atomic is replaced with "volatile unsigned long y" > > - > > which does not violate the standard, but may be considered undesirable by > > some. > > I don't have a strong opinion about this. > > This really does need to be fixed in the "volatile unsigned long y" case, or > device drivers storing constants to device registers will break. So please > fix > this for volatiles as well as atomics. Please open a new PR for this.
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #8 from Uros Bizjak 2013-01-15 19:37:55 UTC --- Actually, the patch from comment(In reply to comment #6) > Created attachment 29169 [details] > Patch that prevents non-atomic immediates in moves to volatile memory location This patch doesn't actually work. Floating point moves split to DImode move pattern, and they assume that all immediates can be passed. Original test can be fixed on 4.8 by following patch: --cut here-- Index: sync.md === --- sync.md (revision 195207) +++ sync.md (working copy) @@ -225,11 +225,8 @@ } /* Otherwise use a store. */ - if (INTVAL (operands[2]) & IX86_HLE_RELEASE) - emit_insn (gen_atomic_store_1 (operands[0], operands[1], -operands[2])); - else - emit_move_insn (operands[0], operands[1]); + emit_insn (gen_atomic_store_1 (operands[0], operands[1], + operands[2])); } /* ... followed by an MFENCE, if required. */ if (model == MEMMODEL_SEQ_CST) --cut here--
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 Uros Bizjak changed: What|Removed |Added Status|NEW |ASSIGNED AssignedTo|unassigned at gcc dot |ubizjak at gmail dot com |gnu.org | Target Milestone|--- |4.7.3 --- Comment #7 from Uros Bizjak 2013-01-15 14:29:44 UTC --- Attached patch generates: movabsq $4294967298, %rdx subl$1, %eax movq%rdx, y(%rip) movabsq $12884901892, %rdx mfence movq%rdx, y(%rip) mfence while non-patched compiler generates: movl$2, y(%rip) movl$1, y+4(%rip) subl$1, %eax mfence movl$4, y(%rip) movl$3, y+4(%rip) mfence
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #6 from Uros Bizjak 2013-01-15 14:25:33 UTC --- Created attachment 29169 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29169 Patch that prevents non-atomic immediates in moves to volatile memory location
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 --- Comment #5 from Uros Bizjak 2013-01-15 14:22:14 UTC --- Obviously, not all DImode immediates are atomic. I have a patch that prohibits moves of immediates that do not satisfy "e" constraints to volatile memories.
[Bug target/55981] std::atomic store is split in two smaller stores
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55981 Paul E. McKenney changed: What|Removed |Added CC||paulmck at linux dot ||vnet.ibm.com --- Comment #4 from Paul E. McKenney 2013-01-15 12:30:04 UTC --- (In reply to comment #2) > Btw, the same happens if atomic is replaced with "volatile unsigned long y" - > which does not violate the standard, but may be considered undesirable by > some. > I don't have a strong opinion about this. This really does need to be fixed in the "volatile unsigned long y" case, or device drivers storing constants to device registers will break. So please fix this for volatiles as well as atomics.
