Description
Counts the number of contiguous, most-significant, leading zero bits in a data value. If available on the targeted architecture an alternate optimized implementation can be defined.
Files
cpu_core.h/cpu_core.c / Specific CPU/compiler cpu_a.asm
Prototypes
Arguments
val
Data value to count leading zero bits.
Returned Value
Number of contiguous, most-significant, leading zero bits in val.
Required Configuration
CPU_CntLeadZeros() available and implemented in cpu_core.c if CPU_CFG_LEAD_ZEROS_ASM_PRESENT is not #define'd in cpu_cfg.h (or cpu.h), but should be implemented in cpu_a.asm (or cpu_a.s) if CPU_CFG_LEAD_ZEROS_ASM_PRESENT is #define'd in cpu_cfg.h (or cpu.h) [see Core Library Configuration].
Each CPU_CntLeadZerosXX() is available and implemented in cpu_core.c based on CPU_CFG_DATA_SIZE_MAX configuration as #define'd in cpu.h :
Function available: if CPU_CFG_DATA_SIZE_MAX configuration:
CPU_CntLeadZero08() = CPU_WORD_SIZE_08CPU_CntLeadZero16() = CPU_WORD_SIZE_16
CPU_CntLeadZero32() = CPU_WORD_SIZE_32
CPU_CntLeadZero64() = CPU_WORD_SIZE_64
Notes / Warnings
None.