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BNDCN

BNDCN clears the bound-checking control flag (BNDCN) in the BNDCN register, effectively disabling bound checking for subsequent instructions.

The table after the description covers what the source and destinations can be.

DO NOT support LOCK

This instruction is only available in 64-bit mode. It is not supported in compatibility mode.

The BNDCN instruction does not affect the bound registers themselves; it only modifies the control flag that determines whether bound-checking instructions should trigger an exception. Failure to set this flag correctly before performing bound-checked memory accesses may lead to unexpected #GP exceptions if bounds are violated.