diff options
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/i386/include/arch/romcc_io.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/arch/i386/include/arch/romcc_io.h b/src/arch/i386/include/arch/romcc_io.h index 7d3d50e39c..d67b3b60d6 100644 --- a/src/arch/i386/include/arch/romcc_io.h +++ b/src/arch/i386/include/arch/romcc_io.h @@ -35,6 +35,18 @@ static void hlt(void) __builtin_hlt(); } +int log2(int value) +{ + /* __builtin_bsr is a exactly equivalent to the x86 machine + * instruction with the exception that it returns -1 + * when the value presented to it is zero. + * Otherwise __builtin_bsr returns the zero based index of + * the highest bit set. + */ + return __builtin_bsr(value); +} + + typedef __builtin_msr_t msr_t; static msr_t rdmsr(unsigned long index) |