[Bug sanitizer/55309] gcc's address-sanitizer 66% slower than clang's

[kcc at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55309

--- Comment #6 from Kostya Serebryany <kcc at gcc dot gnu.org> 2013-02-05 09:21:59 UTC ---
I am slightly confused. Are we discussing compile time or test-run-time? 
I've just built SPEC 2006 with -fsanitize=address -O2
gcc: r195706
clang: r174324
Measured on Intel(R) Xeon(R) CPU W3690  @ 3.47GHz

                           clang         gcc
       400.perlbench,      1209.00,        -1.00,        -0.00
           401.bzip2,       885.00,      1187.00,         1.34
             403.gcc,       739.00,       756.00,         1.02
             429.mcf,       602.00,       612.00,         1.02
           445.gobmk,       840.00,      1191.00,         1.42
           456.hmmer,      1304.00,      1838.00,         1.41
           458.sjeng,       923.00,      1326.00,         1.44
      462.libquantum,       543.00,       481.00,         0.89
         464.h264ref,      1271.00,        -1.00,        -0.00
         471.omnetpp,       631.00,       624.00,         0.99
           473.astar,       672.00,       765.00,         1.14
       483.xalancbmk,       500.00,       521.00,         1.04
            433.milc,       710.00,       629.00,         0.89
            444.namd,       637.00,       539.00,         0.85
          447.dealII,       650.00,       714.00,         1.10
          450.soplex,       389.00,       419.00,         1.08
          453.povray,       459.00,       432.00,         0.94
             470.lbm,       388.00,       409.00,         1.05
         482.sphinx3,       998.00,      1335.00,         1.34


400.perlbench fails with a real asan-ish warning 
(clang can use a blacklist file and disables instrumentation for the buggy
function.
See https://code.google.com/p/address-sanitizer/wiki/FoundBugs#Spec_CPU_2006
and 
https://code.google.com/p/address-sanitizer/wiki/AddressSanitizer#Turning_off_instrumentation)

464.h264ref with gcc loops forever, I did not investigate why. 

So, on average clang+asan is faster than gcc-asan (up to 40%!), 
but in some cases (mostly, FP code) gcc is faster (up to 15%)