The Computer Language
23.03 Benchmarks Game

C gcc versus C clang fastest performance

Always look at the source code.

If the fastest programs are hand-written vector instructions, does the host language matter? You might be more interested in the less optimised programs — more seconds, less gz source code.

fannkuch-redux
source secs mem gz cpu secs
C clang #6 2.05 11,236 1576 8.13
C gcc #6 2.10 11,236 1576 8.34
C clang #4 13.11 11,248 1183 13.11
C gcc #4 14.04 11,236 1183 14.03
C gcc #5 7.53 11,224 910 29.37
C clang #5 8.24 11,160 910 32.64
C clang #2 8.82 11,208 1557 34.58
C clang #3 36.31 11,236 567 36.31
C clang 38.34 11,208 508 38.32
C gcc #3 39.56 11,248 567 39.56
C gcc 42.02 11,244 508 42.02
C gcc #2 11.12 11,236 1557 43.67
n-body
source secs mem gz cpu secs
C gcc #9 2.08 11,392 1633 2.08
C clang #9 2.21 11,392 1633 2.21
C gcc #8 4.01 11,392 1391 4.01
C gcc #4 4.41 11,392 1490 4.41
C clang #4 4.76 11,392 1490 4.76
C gcc #5 5.42 11,392 1429 5.42
C clang #5 5.62 11,392 1429 5.62
C clang #8 5.63 11,392 1391 5.63
C clang #6 5.75 11,392 1180 5.75
C clang #2 5.87 11,392 1263 5.87
C clang 5.98 11,392 1173 5.98
C clang #3 6.33 11,392 1208 6.33
C gcc #6 6.61 11,392 1180 6.60
C gcc #2 6.70 11,392 1263 6.70
C gcc 6.75 11,392 1173 6.75
C gcc #7 6.80 11,392 1244 6.80
C clang #7 6.92 11,392 1244 6.92
C gcc #3 7.25 11,392 1208 7.25
spectral-norm
source secs mem gz cpu secs
C clang #6 0.39 11,392 1197 1.55
C gcc #6 0.40 11,392 1197 1.57
C gcc #4 0.71 11,392 1139 2.84
C clang #5 0.71 11,392 569 2.84
C gcc #7 0.71 11,392 900 2.84
C gcc #5 0.73 11,392 569 2.87
C clang #4 0.73 11,392 1139 2.88
C clang #8 0.76 11,392 935 3.01
C clang 5.31 11,392 383 5.31
C gcc 5.39 11,392 383 5.38
C clang #3 1.42 11,392 463 5.67
C gcc #3 1.44 11,392 463 5.70
C clang #7 1.83 11,392 900 7.08
C gcc #8   Make Error  
mandelbrot
source secs mem gz cpu secs
C clang #9 1.28 33,932 694 5.11
C gcc #6 1.30 32,992 1135 5.17
C clang #8 1.53 34,548 782 6.09
C gcc #8 1.63 33,256 782 6.29
C clang #4 3.47 33,792 799 13.84
C gcc #4 3.47 32,576 799 13.86
C gcc #7 3.49 33,000 994 13.87
C gcc 3.47 32,532 822 13.88
C clang 3.48 32,888 822 13.90
C gcc #3 3.52 32,860 763 14.07
C clang #7 3.54 34,040 994 14.08
C clang #3 3.55 33,044 763 14.16
C gcc #9 4.25 33,036 694 16.41
C gcc #2 25.21 11,180 406 25.21
C clang #2 25.44 11,232 406 25.44
C clang #6   Make Error  
pidigits
source secs mem gz cpu secs
C gcc #2 0.81 11,392 416 0.81
C clang #2 0.81 11,392 416 0.81
C clang 0.88 11,392 452 0.88
C gcc 0.88 11,392 452 0.88
regex-redux
source secs mem gz cpu secs
C gcc #5 0.80 152,148 1397 2.02
C clang #5 0.81 154,176 1397 2.78
C clang #2 3.21 103,260 1115 3.21
C gcc #2 3.22 103,248 1115 3.22
C gcc #4 0.94 152,004 1230 3.26
C gcc #3 1.72 103,812 1266 3.30
C clang #4 0.94 154,012 1230 3.68
C clang #3 1.75 105,720 1266 4.32
fasta
source secs mem gz cpu secs
C clang #9 0.78 11,392 1463 0.78
C gcc #9 0.78 11,284 1463 0.78
C clang #5 1.22 11,392 1281 1.22
C gcc #5 1.30 11,392 1281 1.30
C clang #8 2.45 11,392 1293 2.45
C gcc #6 0.94 11,392 1930 2.76
C gcc #8 2.91 11,392 1293 2.91
C clang #4 2.95 11,392 1240 2.95
C clang #6 1.01 11,288 1930 2.95
C gcc #4 3.07 11,392 1240 3.07
C gcc #2 0.81 11,392 2268 3.23
C clang #2 0.82 11,288 2268 3.26
C gcc #7 0.84 11,392 2011 3.26
C clang #7 0.84 11,392 2011 3.26
C gcc 3.72 11,392 1206 3.72
C clang 3.72 11,392 1206 3.72
C gcc #3 4.49 11,288 819 4.49
C clang #3 4.56 11,260 819 4.56
k-nucleotide
source secs mem gz cpu secs
C clang 5.97 128,860 1506 12.47
C gcc 3.77 129,952 1506 12.67
reverse-complement
source secs mem gz cpu secs
C clang #7 0.42 499,204 1895 0.59
C gcc #7 0.43 499,200 1895 0.62
C clang #8 0.46 499,624 1543 0.70
C gcc #8 0.48 499,404 1543 0.80
C gcc #6 0.89 715,812 820 1.28
C gcc #5 1.46 993,848 647 1.46
C gcc #2 1.01 993,892 750 1.52
C clang #2 1.10 993,892 750 1.62
C clang #5 2.01 993,848 647 2.01
C gcc #4 3.68 500,380 709 3.68
C clang #4 3.73 500,380 709 3.73
C clang #6 0.95 726,524 820 3.79
binary-trees
source secs mem gz cpu secs
C gcc #2 1.57 168,448 809 4.11
C gcc #3 1.73 134,444 836 4.46
C clang #2 1.67 169,692 809 5.44
C clang #3 1.77 134,200 836 5.59
C clang 17.82 264,056 654 17.82
C gcc 21.78 264,232 654 21.78
C gcc #5 8.49 351,268 908 31.09
C clang #5 8.97 351,200 908 32.22
C gcc

12.2.0-3ubuntu1

C clang

Ubuntu clang version 15.0.2-1