This content has not been validated; it was AI-generated following the x86-64 ISA Documentation generation process to maintain high quality. However, as no human has verified this data, errors may exist. If the accuracy of this data is critical, please consult the Intel SDM. The model used to generate this is gemma4:31b

VFPCLASSPD

Classifies the double-precision floating-point value in the source operand according to the specified classification. The result is stored in the destination operand.

The following table covers what the source and destinations can be.

DO NOT support LOCK

This instruction is only available in compatibility mode when targeting x86-64. It is not supported in 64-bit mode.

The destination must be a 32-bit register or memory location (dword) to accommodate the classification result. Failure to provide a 32-bit destination will result in an invalid encoding or unintended memory corruption.