http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55309
Dodji Seketeli <dodji at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Attachment #29366|0 |1 is obsolete| | --- Comment #22 from Dodji Seketeli <dodji at gcc dot gnu.org> 2013-02-06 15:02:44 UTC --- Created attachment 29370 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29370 Candidate patch to avoid duplicated intra bb instrumentation > Trying this patch: > % cat inc.cc > void foo(int *a) { > (*a)++; > } > % gcc -fsanitize=address -O2 inc.cc -S -o - | grep __asan_report > call __asan_report_load4 > call __asan_report_store4 > % clang -fsanitize=address -O2 inc.cc -S -o - | grep __asan_report > callq __asan_report_load4 > % > > Is this test expected to work (have one __asan_error call) with this patch? The patch indeed (naively) considers read and write accesses as being different, you are right. I am attaching a patch that does not, and that generates just one __asan_report call here. I'd be nice to know if that makes any change to ... > First results with the patch (c-only tests, train data): > orig patched > 401.bzip2, 89.60, 90.10, 1.01 > 429.mcf, 23.50, 23.90, 1.02 > 456.hmmer, 181.00, 145.00, 0.80 > 462.libquantum, 1.64, 1.64, 1.00 > 464.h264ref, 249.00, 249.00, 1.00 > 433.milc, 20.10, 20.00, 1.00 > 470.lbm, 37.20, 37.20, 1.00 > 482.sphinx3, 17.50, 17.50, 1.00 > > significant speedup on 456.hmmer, no difference elsewhere. ... this. Hopefully, if subsequent intrumentations on same BB on read/write are considered redundant now, we should see some speed difference on more tests. > 3 benchmarks fail to build: > Error: 1x403.gcc 1x445.gobmk 1x458.sjeng > resource.c:431:1: internal compiler error: in > update_mem_ref_hash_table, at > asan.c:460 The updated patch hopefully addresses that too. Thank you for doing this!