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| author | Ronald G. Minnich <rminnich@gmail.com> | 2012-11-27 11:32:38 -0800 |
|---|---|---|
| committer | Ronald G. Minnich <rminnich@gmail.com> | 2012-11-28 07:57:17 +0100 |
| commit | 5079a0d32f2824445cf593dfbcb65598eaa97dee (patch) | |
| tree | 2e6edd336c00f1f3e4937410a9be9537553702be /src/arch/x86/include | |
| parent | acf443191bd035c26ee89c3ca56f065a5111901b (diff) | |
| download | coreboot-5079a0d32f2824445cf593dfbcb65598eaa97dee.tar.xz | |
Remove assembly coded log2 function
As we move to supporting other systems we need to get rid of assembly
where we can. The log2 function in src/lib is identical to the assembly
one (tested for all 32-bit signed integers :-) and takes about 10 ns
to run as opposed to 5ns for the non-portable assembly version. While speed
is good, I think we can spare the 15 ns or so we add to boot time
by using the C version only.
Change-Id: Icafa565eae282c85fa5fc01b3bd1f110cd9aaa91
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: http://review.coreboot.org/1928
Tested-by: build bot (Jenkins)
Diffstat (limited to 'src/arch/x86/include')
| -rw-r--r-- | src/arch/x86/include/bitops.h | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/src/arch/x86/include/bitops.h b/src/arch/x86/include/bitops.h deleted file mode 100644 index 9206465c77..0000000000 --- a/src/arch/x86/include/bitops.h +++ /dev/null @@ -1,20 +0,0 @@ -#ifndef I386_BITOPS_H -#define I386_BITOPS_H - -/** - * log2 - Find the truncated log base 2 of x - */ - -static inline unsigned long log2(unsigned long x) -{ - unsigned long r = 0; - __asm__( - "bsrl %1, %0\n\t" - "jnz 1f\n\t" - "movl $-1, %0\n\t" - "1:\n\t" - : "=r" (r) : "r" (x)); - return r; - -} -#endif /* I386_BITOPS_H */ |