* [Bug 1001528] New: compat/posix: porting to GCC 4.6
@ 2012-03-09 20:27 bugzilla-daemon
2012-03-11 23:19 ` [Bug 1001528] " bugzilla-daemon
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: bugzilla-daemon @ 2012-03-09 20:27 UTC (permalink / raw)
To: ecos-patches
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Summary: compat/posix: porting to GCC 4.6
Product: eCos
Version: CVS
Platform: All
OS/Version: Other
Status: NEW
Severity: minor
Priority: low
Component: Patches and contributions
AssignedTo: unassigned@bugs.ecos.sourceware.org
ReportedBy: sergei.gavrikov@gmail.com
CC: ecos-patches@ecos.sourceware.org
Class: Advice Request
Created an attachment (id=1635)
--> (http://bugs.ecos.sourceware.org/attachment.cgi?id=1635)
Fix new warnings for unused variables
Porting to GCC 4.6 http://gcc.gnu.org/gcc-4.6/porting_to.html
Fixed new warnings in `posix' package.
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^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug 1001528] compat/posix: porting to GCC 4.6 2012-03-09 20:27 [Bug 1001528] New: compat/posix: porting to GCC 4.6 bugzilla-daemon @ 2012-03-11 23:19 ` bugzilla-daemon 2012-03-12 17:36 ` bugzilla-daemon ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: bugzilla-daemon @ 2012-03-11 23:19 UTC (permalink / raw) To: ecos-patches Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001528 Jonathan Larmour <jifl@ecoscentric.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO CC| |jifl@ecoscentric.com AssignedTo|unassigned@bugs.ecos.source |jifl@ecoscentric.com |ware.org | --- Comment #1 from Jonathan Larmour <jifl@ecoscentric.com> 2012-03-11 23:19:11 GMT --- I'm happy with the mqueue part. I'm less certain about the signal2 change - this might mean that with GCC 4.6, the assignment of 'x' might be optimised away. We have to make sure it isn't because of what we're trying to achieve in that function. Do you have a disassembly of that function when compiled with GCC 4.6 and -O2 ? Jifl -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug 1001528] compat/posix: porting to GCC 4.6 2012-03-09 20:27 [Bug 1001528] New: compat/posix: porting to GCC 4.6 bugzilla-daemon 2012-03-11 23:19 ` [Bug 1001528] " bugzilla-daemon @ 2012-03-12 17:36 ` bugzilla-daemon 2012-03-13 12:34 ` bugzilla-daemon ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: bugzilla-daemon @ 2012-03-12 17:36 UTC (permalink / raw) To: ecos-patches Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001528 --- Comment #2 from Sergei Gavrikov <sergei.gavrikov@gmail.com> 2012-03-12 17:35:57 GMT --- > I'm happy with the mqueue part. I'm less certain about the signal2 > change - this might mean that with GCC 4.6, the assignment of 'x' > might be optimised away. We have to make sure it isn't because of what > we're trying to achieve in that function. Do you have a disassembly of > that function when compiled with GCC 4.6 and -O2 ? Thank you for your point. I will investigate next days as I am little unwell. -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug 1001528] compat/posix: porting to GCC 4.6 2012-03-09 20:27 [Bug 1001528] New: compat/posix: porting to GCC 4.6 bugzilla-daemon 2012-03-11 23:19 ` [Bug 1001528] " bugzilla-daemon 2012-03-12 17:36 ` bugzilla-daemon @ 2012-03-13 12:34 ` bugzilla-daemon 2012-03-13 14:27 ` bugzilla-daemon 2012-03-13 14:54 ` bugzilla-daemon 4 siblings, 0 replies; 6+ messages in thread From: bugzilla-daemon @ 2012-03-13 12:34 UTC (permalink / raw) To: ecos-patches Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001528 --- Comment #3 from Sergei Gavrikov <sergei.gavrikov@gmail.com> 2012-03-13 12:34:09 GMT --- Sorry, for delayed answer. Snippets are below: tests/signal2.c:128 volatile int x; volatile CYG_ADDRESS p=(CYG_ADDRESS) &jbuf; do { x = *(volatile int *)(p); p += (CYG_ADDRESS)0x100000; } while( p != (CYG_ADDRESS)&jbuf ); GCC 4.3 (-O2) 16c: e58d400c str r4, [sp, #12] 170: e1a00004 mov r0, r4 174: e59d300c ldr r3, [sp, #12] 178: e5932000 ldr r2, [r3] 17c: e58d2010 str r2, [sp, #16] 180: e59d300c ldr r3, [sp, #12] 184: e2833601 add r3, r3, #1048576 ; 0x100000 188: e58d300c str r3, [sp, #12] 18c: e59d200c ldr r2, [sp, #12] 190: e1500002 cmp r0, r2 194: 1afffff6 bne 174 <main+0x174> GCC 4.6 (-O2) 158: e58d4014 str r4, [sp, #20] 15c: e59d3014 ldr r3, [sp, #20] 160: e5933000 ldr r3, [r3] 164: e58d3010 str r3, [sp, #16] 168: e59d3014 ldr r3, [sp, #20] 16c: e2833601 add r3, r3, #1048576 ; 0x100000 170: e58d3014 str r3, [sp, #20] 174: e59d3014 ldr r3, [sp, #20] 178: e1540003 cmp r4, r3 17c: 1afffff6 bne 15c <main+0x15c> Thus, new compiler uses less registers, but, GCC 4.6 provides the same functionality (I tested the loop in GDB, and I got `sigbus' call at the end with new code). Though, you are right, a using CYGBLD_ATTRIB_UNUSED for the forced volatile variables would break smart things. Then, maybe leave signal2 test without the changes as I tested the code for one CPU only? What is your verdict? -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug 1001528] compat/posix: porting to GCC 4.6 2012-03-09 20:27 [Bug 1001528] New: compat/posix: porting to GCC 4.6 bugzilla-daemon ` (2 preceding siblings ...) 2012-03-13 12:34 ` bugzilla-daemon @ 2012-03-13 14:27 ` bugzilla-daemon 2012-03-13 14:54 ` bugzilla-daemon 4 siblings, 0 replies; 6+ messages in thread From: bugzilla-daemon @ 2012-03-13 14:27 UTC (permalink / raw) To: ecos-patches Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001528 --- Comment #4 from Jonathan Larmour <jifl@ecoscentric.com> 2012-03-13 14:26:50 GMT --- Thanks for the disassembly. (In reply to comment #3) > > Thus, new compiler uses less registers, but, GCC 4.6 provides the same > functionality (I tested the loop in GDB, and I got `sigbus' call at the > end with new code). Though, you are right, a using CYGBLD_ATTRIB_UNUSED > for the forced volatile variables would break smart things. Well, it _could_ break things if the gcc policy was that even volatile accesses could be eliminated for things which are both unused and explicitly marked unused. That appears not to be the case, which is good. > Then, maybe leave signal2 test without the changes as I tested the code > for one CPU only? What is your verdict? No it can go. If GCC thought it was unused and could be discarded it would definitely get rid of it during optimisation, and that would be true on all architectures. So your full patch including signal2 change can go in now, thanks! Jifl -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug 1001528] compat/posix: porting to GCC 4.6 2012-03-09 20:27 [Bug 1001528] New: compat/posix: porting to GCC 4.6 bugzilla-daemon ` (3 preceding siblings ...) 2012-03-13 14:27 ` bugzilla-daemon @ 2012-03-13 14:54 ` bugzilla-daemon 4 siblings, 0 replies; 6+ messages in thread From: bugzilla-daemon @ 2012-03-13 14:54 UTC (permalink / raw) To: ecos-patches Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001528 Sergei Gavrikov <sergei.gavrikov@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |RESOLVED Resolution| |CURRENTRELEASE --- Comment #5 from Sergei Gavrikov <sergei.gavrikov@gmail.com> 2012-03-13 14:53:59 GMT --- Checked-in. -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-03-13 14:54 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-03-09 20:27 [Bug 1001528] New: compat/posix: porting to GCC 4.6 bugzilla-daemon 2012-03-11 23:19 ` [Bug 1001528] " bugzilla-daemon 2012-03-12 17:36 ` bugzilla-daemon 2012-03-13 12:34 ` bugzilla-daemon 2012-03-13 14:27 ` bugzilla-daemon 2012-03-13 14:54 ` bugzilla-daemon
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