Для удовлетворения любопытства, скачал openwatcom 1.8 (такой бывший когда то известным компилятор c/c++), исходники под линукс. собрал, и попробовал тестовую задачку, вот эту вот

Резуьтаты:

GCC

walrus@home:/home/walrus/sandbox$ gcc btr.c -O3 -o btr_gcc -lm
walrus@home:/home/walrus/sandbox$ time ./btr_gcc 20
stretch tree of depth 21 check: -1
2097152 trees of depth 4 check: -2097152
524288 trees of depth 6 check: -524288
131072 trees of depth 8 check: -131072
32768 trees of depth 10 check: -32768
8192 trees of depth 12 check: -8192
2048 trees of depth 14 check: -2048
512 trees of depth 16 check: -512
128 trees of depth 18 check: -128
32 trees of depth 20 check: -32
long lived tree of depth 20 check: -1

real 1m2.138s
user 1m1.852s
sys 0m0.120s

Watcom

walrus@home:/home/walrus/sandbox$ PATH=$PATH:/opt/watcom/binl WATCOM=/opt/watcom owcc -I/opt/watcom/h -O3 -obtr_wc btr.c
walrus@home:/home/walrus/sandbox$ time ./btr_wc 20
stretch tree of depth 21 check: -1
2097152 trees of depth 4 check: -2097152
524288 trees of depth 6 check: -524288
131072 trees of depth 8 check: -131072
32768 trees of depth 10 check: -32768
8192 trees of depth 12 check: -8192
2048 trees of depth 14 check: -2048
512 trees of depth 16 check: -512
128 trees of depth 18 check: -128
32 trees of depth 20 check: -32
long lived tree of depth 20 check: -1

real 0m47.934s
user 0m47.675s
sys 0m0.136s

62 секунды против 48 в пользу watcom-а. Ай да старик watcom!! Вот это да!

UPD Да, забыл – ubuntu 9.04 32 AMD, 4000+, gcc gcc версия 4.3.3 (Ubuntu 4.3.3-5ubuntu4), watcom :

owcc -v Open Watcom C/C++32 Compiler Driver Program Version 1.8beta1 LA Portions Copyright © 1988-2002 Sybase, Inc. All Rights Reserved. Source code is available under the Sybase Open Watcom Public License. See http://www.openwatcom.org/ for details.