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

VFNMSUB231SD

Subtracts the product of two double-precision floating-point values from a third value and negates the result. The operation is defined as: destination = -(source1 - (source2 * source3)).

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

DO NOT support LOCK

This instruction requires the AVX support feature. It is only available in 64-bit mode or compatibility mode.

The instruction uses the VEX encoding scheme; therefore, it does not support the LOCK prefix. Using a memory operand for the first source operand is permitted, but the destination must be a register (XMM).

When executing this instruction, the precision control in the MXCSR register SHALL determine the rounding direction. If the result of the operation exceeds the maximum representable value for a double-precision float, a #O exception SHALL be triggered. If the result is inexact, a #P exception SHALL be triggered. Ensure that the XMM registers are properly aligned to 16 bytes when using memory operands to avoid general protection faults or performance degradation.