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f0d1b0b30d
This facility provides three entry points:
ilog2() Log base 2 of unsigned long
ilog2_u32() Log base 2 of u32
ilog2_u64() Log base 2 of u64
These facilities can either be used inside functions on dynamic data:
int do_something(long q)
{
...;
y = ilog2(x)
...;
}
Or can be used to statically initialise global variables with constant values:
unsigned n = ilog2(27);
When performing static initialisation, the compiler will report "error:
initializer element is not constant" if asked to take a log of zero or of
something not reducible to a constant. They treat negative numbers as
unsigned.
When not dealing with a constant, they fall back to using fls() which permits
them to use arch-specific log calculation instructions - such as BSR on
x86/x86_64 or SCAN on FRV - if available.
[akpm@osdl.org: MMC fix]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Wojtek Kaniewski <wojtekka@toxygen.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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|---|---|---|
| .. | ||
| boot | ||
| kernel | ||
| lib | ||
| mm | ||
| platform | ||
| defconfig | ||
| Kconfig | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Kconfig.ide | ||
| Makefile | ||
| README | ||
linux-2.6 for H8/300 README
Yoshinori Sato <ysato@users.sourceforge.jp>
* Supported CPU
H8/300H and H8S
* Supported Target
1.simulator of GDB
require patches.
2.AE 3068/AE 3069
more information
MICROTRONIQUE <http://www.microtronique.com/>
Akizuki Denshi Tsusho Ltd. <http://www.akizuki.ne.jp> (Japanese Only)
3.H8MAX
see http://ip-sol.jp/h8max/ (Japanese Only)
4.EDOSK2674
see http://www.eu.renesas.com/products/mpumcu/tool/edk/support/edosk2674.html
http://www.azpower.com/H8-uClinux/
* Toolchain Version
gcc-3.1 or higher and patch
see arch/h8300/tools_patch/README
binutils-2.12 or higher
gdb-5.2 or higher
The environment that can compile a h8300-elf binary is necessary.
* Userland Develop environment
used h8300-elf toolchains.
see http://www.uclinux.org/pub/uClinux/ports/h8/
* A few words of thanks
Porting to H8/300 serieses is support of Information-technology Promotion Agency, Japan.
I thank support.
and All developer/user.