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author | Kevin Ryde <user42@zip.com.au> | 2000-11-20 21:43:03 +0100 |
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committer | Kevin Ryde <user42@zip.com.au> | 2000-11-20 21:43:03 +0100 |
commit | 657ba334f30ed26c9b346dfd718f0e0658c103a2 (patch) | |
tree | f905f87c005aed6d844d8a421d863e5455735f9e /tune/README | |
parent | 07989342fe9932d4f0c0e82708ef89fa4e5b9f2d (diff) | |
download | gmp-657ba334f30ed26c9b346dfd718f0e0658c103a2.tar.gz |
* tune/Makefile.am (LDFLAGS): Use -all-static.
(speed-dynamic): Dynamic linked version of speed.c.
* tune/README: Update.
Diffstat (limited to 'tune/README')
-rw-r--r-- | tune/README | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/tune/README b/tune/README index a7eb34cc7..e4dec1c15 100644 --- a/tune/README +++ b/tune/README @@ -114,7 +114,7 @@ generally an idle machine will be necessary to be certain of consistent results. The CPU frequency is needed if times in cycles are to be displayed, and it's -always needed when using a cycle counter time base. time.c knows how to get +always needed when using a cycle counter time base. freq.c knows how to get the frequency on some systems, but when that fails, or needs to be overridden, an environment variable GMP_CPU_FREQUENCY can be used (in Hertz). For example in "bash" on a 650 MHz machine, @@ -279,16 +279,16 @@ mpz_add. Don't be surprised if the mallocing is quite slow. ./speed -s 10 -c mpz_init_realloc_clear mpz_add -The normal libtool compilation of the speed program does a static link to -libgmp.la and libspeed.la, but will end up dynamic linked to libc. -Depending on the system, a dynamic linked malloc may be noticeably slower -than a static one, and there may be value in re-running the libtool link -command to static link libc for comparison. The example below does a 10 -limb malloc/free or malloc/realloc/free to test the C library. Of course a -real world program has big problems if it's doing so many mallocs and frees -that it gets slowed down by a dynamic linked malloc. +On some systems malloc and free are much slower when dynamic linked. The +speed-dynamic program can be used to see this. For example the following +measures malloc/free, first static then dynamic. + + ./speed -s 10 -c malloc_free + ./speed-dynamic -s 10 -c malloc_free + +Of course a real world program has big problems if it's doing so many +mallocs and frees that it gets slowed down by a dynamic linked malloc. - ./speed -s 10 -c malloc_free malloc_realloc_free |