[Bug target/19923] [4.0/4.1 Regression] openssl is slower when compiled with gcc 4.0 than 3.3

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2005-06-18 06:24 -------
Looks to me like gcc-3.4.3 is known to fail, too, depending on the CPU.
Anthony Danalis and I came up with a little script to run foo4.i
on various processors with various values for -mtune, which I'll
attach; here are the results for four different x86 variants.

The last two columns are the time on gcc-3.4.3 and gcc-4.0.0
divided by the time on gcc-2.95.3, so any value above 1.0 in
the last column is a performance regression.  
Rows are sorted by the last column.  The first five
rows represent performance regressions for gcc-3.4.3;
the first three also represent performance regressions
for gcc-4.0.0.

family,model,name               pic?  tune      [t_295, t_343, t_400]
[t_295/t_295, t_343/t_295, t_400/t_295]

6,8, Pentium III (Coppermine),  -fPIC athlon-xp [9.25, 16.22, 18.79]  [1.00,
1.75, 2.03]
15,2, Xeon(TM) CPU 2.60GHz,     -fPIC pentium4  [1.91, 3.89, 3.27]    [1.00,
2.04, 1.71]
6,8, Pentium III (Coppermine),  -fPIC pentium3  [9.15, 10.10, 13.20]  [1.00,
1.10, 1.44]
15,2, Xeon(TM) CPU 2.60GHz,     -fPIC athlon-xp [1.91, 2.00, 1.95]    [1.00,
1.05, 1.02]
6,8, Pentium III (Coppermine),  -fPIC pentium4  [9.27, 10.49,  8.87]  [1.00,
1.13, 0.96]

--- ok below this line ---

6,8, Pentium III (Coppermine),        pentium4  [14.74, 13.71, 14.12] [1.00,
0.93, 0.96]
15,4, Athlon(tm) 64 3000+,      -fPIC pentium4  [4.12, 3.68, 3.74]    [1.00,
0.89, 0.91]
15,4, Pentium(R) 4 CPU 3.20GHz, -fPIC pentium4  [2.48, 2.18, 2.09]    [1.00,
0.88, 0.84]
15,4, Athlon(tm) 64 3000+,      -fPIC athlon-xp [4.12, 3.50, 3.20]    [1.00,
0.85, 0.78]
15,4, Pentium(R) 4 CPU 3.20GHz,       pentium4  [2.17, 1.07, 1.07]    [1.00,
0.49, 0.49]
6,8, Pentium III (Coppermine),        pentium3  [14.22,  6.26,  6.46] [1.00,
0.44, 0.45]
6,8, Pentium III (Coppermine),        athlon-xp [14.93,  6.26,  6.27] [1.00,
0.42, 0.42]
15,4, Athlon(tm) 64 3000+,            pentium4  [3.65, 1.39, 1.39]    [1.00,
0.38, 0.38]
15,4, Athlon(tm) 64 3000+,            athlon-xp [3.65, 1.39, 1.40]    [1.00,
0.38, 0.38]
15,2, Xeon(TM) CPU 2.60GHz,           pentium4  [6.42, 0.97, 0.98]    [1.00,
0.15, 0.15]


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19923