gcc-7.2 vs clang-4.0

root@turbo:/tmp/benchs# make clean ; make CFLAGS=-O3 CC=gcc-7 && ./dry 2>/dev/null |tail -1
rm -f dry flops *.o
gcc-7 -O3 -c dry.c -o dry1.o -Wall
gcc-7 -O3 -DPASS2 dry.c dry1.o -o dry -Wall
gcc-7 -O3 -DUNIX flops.c -o flops -Wall
Dhrystones per Second:                          54059900

root@turbo:/tmp/benchs# make clean ; make CFLAGS=-O3 CC=clang && ./dry 2>/dev/null |tail -1
rm -f dry flops *.o
clang -O3 -c dry.c -o dry1.o -Wall
clang -O3 -DPASS2 dry.c dry1.o -o dry -Wall
clang -O3 -DUNIX flops.c -o flops -Wall
Dhrystones per Second:                          57019044

root@turbo:/tmp/benchs# make clean ; make CFLAGS=-O3 CC=gcc-7 && ./flops
rm -f dry flops *.o
gcc-7 -O3 -c dry.c -o dry1.o -Wall
gcc-7 -O3 -DPASS2 dry.c dry1.o -o dry -Wall
gcc-7 -O3 -DUNIX flops.c -o flops -Wall

   FLOPS C Program (Double Precision), V2.0 18 Dec 1992

   Module     Error        RunTime      MFLOPS
                            (usec)
     1      4.0146e-13      0.0018   7797.5593
     2     -1.4166e-13      0.0004  16836.3296
     3      4.7184e-14      0.0025   6790.8748
     4     -1.2557e-13      0.0023   6388.3147
     5     -1.3800e-13      0.0046   6305.7347
     6      3.2380e-13      0.0044   6533.3220
     7     -8.4583e-11      0.0026   4599.0950
     8      3.4867e-13      0.0046   6514.3458

   Iterations      =  512000000
   NullTime (usec) =     0.0000
   MFLOPS(1)       = 11348.2674
   MFLOPS(2)       =  5818.9753
   MFLOPS(3)       =  6375.8156
   MFLOPS(4)       =  6548.9297

root@turbo:/tmp/benchs# make clean ; make CFLAGS=-O3 CC=clang && ./flops
rm -f dry flops *.o
clang -O3 -c dry.c -o dry1.o -Wall
clang -O3 -DPASS2 dry.c dry1.o -o dry -Wall
clang -O3 -DUNIX flops.c -o flops -Wall

   FLOPS C Program (Double Precision), V2.0 18 Dec 1992

   Module     Error        RunTime      MFLOPS
                            (usec)
     1      4.0146e-13      0.0015   9363.1173
     2     -1.4166e-13      0.0004  19002.1738
     3      4.7184e-14      0.0026   6639.1662
     4     -1.2557e-13      0.0024   6271.3639
     5     -1.3800e-13      0.0037   7924.7871
     6      3.2380e-13      0.0035   8241.1056
     7     -8.4583e-11      0.0027   4482.0477
     8      3.4867e-13      0.0047   6400.7681

   Iterations      =  512000000
   NullTime (usec) =     0.0000
   MFLOPS(1)       = 11811.5860
   MFLOPS(2)       =  6246.0563
   MFLOPS(3)       =  6955.6103
   MFLOPS(4)       =  6915.8030