[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 torvald at gcc dot gnu.org changed: What|Removed |Added Status|WAITING |RESOLVED Resolution||FIXED --- Comment #11 from torvald at gcc dot gnu.org 2012-12-05 19:18:42 UTC --- I can't reproduce this anymore. I also had a brief look at the binary code that showed the problem previously and didn't see the problematic pattern anymore. So it seems that this is fixed.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 Aldy Hernandez changed: What|Removed |Added Status|NEW |WAITING --- Comment #10 from Aldy Hernandez 2012-12-03 18:51:44 UTC --- I no longer see a Genome failure on trunk, even though we are stripping off the abnormal edges as part of the expansion of gimple into RTL (as described in comment 8). Perhaps, this could be a nice side-effect of the abnormal edge rewriting that went in with the uninstrumented path? Can someone (Torvald or Patrick) verify this so we can close this PR if appropriate? For the record, this is what I've done. I reverted the returns-twice patch by applying the patch in comment 9. I seem to be running Stamp: 0.9.10 (8 Sept 2008) (from the VERSIONS file in the STAMP distribution). I am testing with current mainline as of trunk@194099. And I am using a Makefile.local of: CC=/build/trunk/install/bin/gcc LDFLAGS="-Wl,-rpath=/build/trunk/install/lib64" THREADS="4" TESTS=test-genome I do a "make clean && make test" and get: cd genome && \ ./genome -t "4" && true Creating gene and segments... done. Gene length = 16384 Segment length = 64 Number segments = 16777216 Sequencing gene... done. Time = 13.305184 Sequence matches gene: yes Deallocating memory... done. This seems correct.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 --- Comment #9 from Aldy Hernandez 2012-12-03 18:43:14 UTC --- Created attachment 28862 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28862 patch to revert the returns twice patch
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 Aldy Hernandez changed: What|Removed |Added AssignedTo|unassigned at gcc dot |aldyh at gcc dot gnu.org |gnu.org | --- Comment #8 from Aldy Hernandez 2012-11-29 17:05:16 UTC --- This should get revisited now that we have redesigned how the back edges are generated. FWIW, all the back edges are removed prior to generating RTL in gimple_expand_cfg(): /* At the moment not all abnormal edges match the RTL representation. It is safe to remove them here as find_many_sub_basic_blocks will rediscover them. In the future we should get this fixed properly. */ I'll revisit this and see if we can resolve this.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 --- Comment #7 from Aldy Hernandez 2012-06-04 16:08:30 UTC --- (In reply to comment #4) > Created attachment 27303 [details] > RBTree microbenchmark test case > > I believe that I'm seeing this in the RSTM suite's RBTree microbenchmark as > well. It appears to be manifesting with the same symptoms as pr47530, > _ITM_commitTransaction is generated as a tail call. An abort in > _ITM_commitTransaction during multithreaded execution corrupts the stack slot > that is used to hold a "time" value. Luke, this is actually PR47530 and unrelated to this PR. I am fixing it for PR47530, and any further discussing will be in that PR.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 Aldy Hernandez changed: What|Removed |Added Priority|P3 |P4 Severity|normal |enhancement
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 --- Comment #6 from Aldy Hernandez 2012-06-01 16:46:27 UTC --- Created attachment 27543 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27543 Proposed patch by Richard Henderson-- untested This is an old, untested patch from rth that attempts to fix the problem without the returns-twice hack. There is some overlap with Patrick Marlier's attempt here: http://gcc.gnu.org/ml/gcc/2012-01/msg00099.html Patch provided here so we don't have to reanalyze everything if/when we revisit this issue.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771
Aldy Hernandez changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed||2012-06-01
Ever Confirmed|0 |1
--- Comment #5 from Aldy Hernandez 2012-06-01
16:39:12 UTC ---
This is a mental note for whenever we decide to pick this up again...
The current approach with the returns-twice patch is a bit heavy handed, as the
register allocator will more-or-less give up across returns-twice. With the
appropriate abnormal edges, the allocator will get more exact info. Whether or
not it's able to do anything extra with this info is a different story...
That's why, we should drop this to ultra low priority-- the returns-twice
approach is good enough.
However, when someone gets bored, the way to debug this is with any trivial
testcase:
int glob;
foo()
{
__transaction_atomic { glob=666; }
}
If one reverts the returns-twice patch referenced in this PR, one sees the
abnormal edges all the way up to *.c.*t.optimized. The edges get corrupted
somewhere in the RTL passes.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771
--- Comment #4 from Luke Dalessandro 2012-05-03
15:06:57 UTC ---
Created attachment 27303
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27303
RBTree microbenchmark test case
I believe that I'm seeing this in the RSTM suite's RBTree microbenchmark as
well. It appears to be manifesting with the same symptoms as pr47530,
_ITM_commitTransaction is generated as a tail call. An abort in
_ITM_commitTransaction during multithreaded execution corrupts the stack slot
that is used to hold a "time" value.
I attached the TreeBench.ii test case so that a second, complex example of the
problem exists.
Static manifestation of bug is "jmp _ITM_commitTransaction" in asm output.
$ g++ -O3 -fgnu-tm -o /dev/stdout -S TreeBench.ii | grep _ITM_commitTransaction
call_ITM_commitTransaction
jmp_ITM_commitTransaction
jmp_ITM_commitTransaction
Runtime manifestation is corrupted "time" output (and thus "throughput" output
as well) under multithreaded execution ("p" command line parameter) of the
optimized executable.
$ g++ -fgnu-tm -o TreeBench TreeBench.ii -lrt
$ ./TreeBench -p2
Verification: Passed
csv, ALG=gcc-tm, B=RBTree, R=34, d=1, p=2, X=0, m=256, S=1, O=1, txns=1251624,
time=101773, throughput=1251621
$ g++ -O3 -fgnu-tm -o TreeBench TreeBench.ii -lrt
$ ./TreeBench -p2
Verification: Passed
csv, ALG=gcc-tm, B=RBTree, R=34, d=1, p=2, X=0, m=256, S=1, O=1,
txns=391668795, time=1336057254755574655, throughput=0
Output from g++ -v -save-temps.
$ g++ -fgnu-tm -O3 -m64 -DSTM_INST_STM -DSTM_API_GCCTM -DSTM_CC_GCC
-DSTM_OS_LINUX -DSTM_CPU_X86 -DSTM_BITS_64 -DSTM_OPT_O3 -DSTM_WS_BYTELOG
-DSINGLE_SOURCE_BUILD -I../include -I../lib -v -save-temps TreeBench.cpp -lrt
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/localdisk/luked/pub/gcc/4.8/bin/../libexec/gcc/x86_64-redhat-linux/4.8.0/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../gcc-4.8/configure --prefix=/u/luked/pub/gcc/4.8
--enable-bootstrap --enable-threads=posix --enable-checking=release
--with-system-zlib --enable-__cxa-atexit --disable-libunwind-exceptions
--enable-linker-build-id --enable-plugins --enable-lto --disable-nls
--enable-ld --enable-gold --with-gmp=/u/luked/pub/gmp-5.0.4-static
--with-mpfr=/u/luked/pub/mpfr-3.1.0-static
--with-mpc=/u/luked/pub/mpc-0.9-static
--with-ppl=/u/luked/pub/ppl-0.11.2-static
--with-cloog=/u/luked/pub/cloog-0.16.3-static --enable-cloog-backend=isl
--with-tune=generic --with-arch-32=i686 --with-gnu-ld --with-gnu-as
--with-plugin-ld=ld.gold --build=x86_64-redhat-linux
--with-host-libstdcxx='/usr/local/lib64/libstdc++.a -lm'
--enable-languages=c,c++,lto : (reconfigured)
Thread model: posix
gcc version 4.8.0 20120502 (experimental) [trunk revision 187050] (GCC)
COLLECT_GCC_OPTIONS='-fgnu-tm' '-O3' '-m64' '-D' 'STM_INST_STM' '-D'
'STM_API_GCCTM' '-D' 'STM_CC_GCC' '-D' 'STM_OS_LINUX' '-D' 'STM_CPU_X86' '-D'
'STM_BITS_64' '-D' 'STM_OPT_O3' '-D' 'STM_WS_BYTELOG' '-D'
'SINGLE_SOURCE_BUILD' '-I' '../include' '-I' '../lib' '-v' '-save-temps'
'-shared-libgcc' '-mtune=generic' '-march=x86-64' '-pthread'
/localdisk/luked/pub/gcc/4.8/bin/../libexec/gcc/x86_64-redhat-linux/4.8.0/cc1plus
-E -quiet -v -I ../include -I ../lib -iprefix
/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/x86_64-redhat-linux/4.8.0/
-D_GNU_SOURCE -D_REENTRANT -D STM_INST_STM -D STM_API_GCCTM -D STM_CC_GCC -D
STM_OS_LINUX -D STM_CPU_X86 -D STM_BITS_64 -D STM_OPT_O3 -D STM_WS_BYTELOG -D
SINGLE_SOURCE_BUILD TreeBench.cpp -m64 -mtune=generic -march=x86-64 -fgnu-tm
-O3 -fpch-preprocess -o TreeBench.ii
ignoring nonexistent directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../x86_64-redhat-linux/include"
ignoring duplicate directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/../../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../include/c++/4.8.0"
ignoring duplicate directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/../../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../include/c++/4.8.0/x86_64-redhat-linux"
ignoring duplicate directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/../../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../include/c++/4.8.0/backward"
ignoring duplicate directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/../../lib/gcc/x86_64-redhat-linux/4.8.0/include"
ignoring duplicate directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/../../lib/gcc/x86_64-redhat-linux/4.8.0/include-fixed"
ignoring nonexistent directory
"/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/../../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
../include
../lib
/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../include/c++/4.8.0
/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/x86_64-redhat-linux/4.8.0/../../../../include/c++/4.8.0/x86_64-redhat-linux
/localdisk/luked/pub/gcc/4.8/bin/../lib/gcc/x86_64-redhat-linux/4.8.0/../
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 torvald at gcc dot gnu.org changed: What|Removed |Added Target Milestone|--- |4.8.0
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 --- Comment #3 from torvald at gcc dot gnu.org 2012-01-31 13:20:32 UTC --- Created attachment 26532 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26532 test for false returns-twice warning Attached a test that triggers a false warning due to the returns-twice hack when -Wclobbered is used. The transactions roll back updates properly.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 Patrick Marlier changed: What|Removed |Added CC||patrick.marlier at gmail ||dot com --- Comment #2 from Patrick Marlier 2012-01-17 22:09:58 UTC --- Just to not forget, one thread about it is here: http://gcc.gnu.org/ml/gcc/2012-01/msg00099.html Patrick Marlier.
[Bug rtl-optimization/51771] trans-mem: abnormal edges get lost or corrupted
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51771 --- Comment #1 from torvald at gcc dot gnu.org 2012-01-05 23:48:36 UTC --- Author: torvald Date: Thu Jan 5 23:48:30 2012 New Revision: 182937 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=182937 Log: Mark transaction begin as returns-twice. PR rtl-optimization/51771 gcc/ * builtin-attrs.def (ATTR_RETURNS_TWICE, ATTR_TM_NOTHROW_RT_LIST): New. * gtm-builtins.def (BUILT_IN_TM_START): Add returns-twice attrib. Modified: trunk/gcc/ChangeLog trunk/gcc/builtin-attrs.def trunk/gcc/gtm-builtins.def
