How to accelerate this program?

[Li Jie]

In article <e0ssod$2q8b$1 at digitaldaemon.com>, Dave says...
>Please send:
>
>- the output from 'dmd -v' 
lijie t # dmd -v
Digital Mars D Compiler v0.150
Copyright (c) 1999-2006 by Digital Mars written by Walter Bright
Documentation: www.digitalmars.com/d/index.html
Usage:
dmd files.d ... { -switch }
.... 

>- output from 'll /usr/lib/libphobos.a'.
lijie t # ll /usr/lib/libphobos.a
-rw-r--r--  1 root root 1157824  4月  4 13:05 /usr/lib/libphobos.a

>- what type of system is 'your system'
My system is gentoo linux 2006.0
Linux kernel version is 2.6.15
g++ version is 3.4.4
dmd version is 0.150

>- how large is the email file in bytes
lijie t # ll email.txt
-rw-r--r--  1 root root 19388869  4月  3 09:27 email.txt

>- which c++ compiler and flags are you using?
I'm using -O2, it takes ~680 ms.
And change to -O3 -fomit-frame-pointer -funroll-loops -mtune=pentium4, it takes
~630 ms.

>- dmd compiler flags for your test.
dmd testd.d -O -release -inline


some tests:
=======================================
lijie t # g++ -o test7 test7.cpp -O3 -fomit-frame-pointer -funroll-loops
-mtune=pentium4
lijie t # ./test7 email.txt email-new.txt
Total used: 637 ms.
lijie t # ./test7 email.txt email-new.txt
Total used: 628 ms.
lijie t # ./test7 email.txt email-new.txt
Total used: 629 ms.
lijie t # ./test7 email.txt email-new.txt
Total used: 639 ms.
lijie t # ./test7 email.txt email-new.txt
Total used: 627 ms.

lijie t # dmd dave_test.d -O -release -inline
gcc dave_test.o -o dave_test -lphobos -lpthread -lm
lijie t # ./dave_test email.txt email-new.txt
3360
lijie t # ./dave_test email.txt email-new.txt
3315
lijie t # ./dave_test email.txt email-new.txt
3344
lijie t # ./dave_test email.txt email-new.txt
3333
lijie t # ./dave_test email.txt email-new.txt
3398


Thanks.