[Bug c++/69564] [5/6 Regression] lto and/or C++ make scimark2 LU slower

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69564

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I don't see any difference though, neither with the fold-const.c change, nor
with the loop-invert.patch (at least on my Haswell-E, -g -Ofast x86_64, single
runs only; though, it shows the LU slowdown with C++ clearly, and also that
clang wins on SOR and Sparse matmult, we win significantly on MonteCarlo and
less significantly on FFT, C LU is comparable):
gcc trunk 20160224
Composite Score:         2482.97
FFT             Mflops:  1982.24    (N=1024)
SOR             Mflops:  1904.08    (100 x 100)
MonteCarlo:     Mflops:   677.65
Sparse matmult  Mflops:  2775.38    (N=1000, nz=5000)
LU              Mflops:  5075.48    (M=100, N=100)
g++ trunk 20160224
Composite Score:         2314.35
FFT             Mflops:  1986.77    (N=1024)
SOR             Mflops:  1903.29    (100 x 100)
MonteCarlo:     Mflops:   678.80
Sparse matmult  Mflops:  2775.33    (N=1000, nz=5000)
LU              Mflops:  4227.54    (M=100, N=100)
g++ trunk 20160224 + fold-const.c MIN/MAX change
Composite Score:         2331.88
FFT             Mflops:  1983.28    (N=1024)
SOR             Mflops:  1906.04    (100 x 100)
MonteCarlo:     Mflops:   676.53
Sparse matmult  Mflops:  2823.60    (N=1000, nz=5000)
LU              Mflops:  4269.96    (M=100, N=100)
g++ trunk 20150224 + fold-const.c MIN/MAX change + loop-invert.patch
Composite Score:         2332.00
FFT             Mflops:  1983.18    (N=1024)
SOR             Mflops:  1905.64    (100 x 100)
MonteCarlo:     Mflops:   674.50
Sparse matmult  Mflops:  2823.55    (N=1000, nz=5000)
LU              Mflops:  4273.14    (M=100, N=100)
clang 3.8
Composite Score:         2418.13
FFT             Mflops:  1583.23    (N=1024)
SOR             Mflops:  2130.27    (100 x 100)
MonteCarlo:     Mflops:   281.80
Sparse matmult  Mflops:  3026.40    (N=1000, nz=5000)
LU              Mflops:  5068.95    (M=100, N=100)
clang++ 3.8
Composite Score:         2434.04
FFT             Mflops:  1595.89    (N=1024)
SOR             Mflops:  2131.09    (100 x 100)
MonteCarlo:     Mflops:   281.63
Sparse matmult  Mflops:  3001.59    (N=1000, nz=5000)
LU              Mflops:  5159.98    (M=100, N=100)