Intel® C++ Compiler Classic Developer Guide and Reference
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Visible to Intel only — GUID: GUID-67C6440B-D49E-4D7C-98A2-667E47ED63CC
Visible to Intel only — GUID: GUID-67C6440B-D49E-4D7C-98A2-667E47ED63CC
_lzcnt_u32/64
Counts the number of leading zero bits in a source operand. Returns operand size as output when source operand is zero. The corresponding Intel® AVX2 instruction is LZCNT.
Syntax
extern unsigned int _lzcnt_u32(unsigned int source); |
extern unsigned __int64 _lzcnt_u64(unsigned __int64 source); |
Arguments
source |
the source operand used for the operation |
Description
Counts the number of leading most significant zero bits in a source operand returning the result into a destination when source operand is 0.
Returns
Result of the operation.