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

LDMXCSR

Loads the MXCSR register from a specified memory location.

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

DO NOT support LOCK

This instruction is available in both 64-bit mode and compatibility mode. It requires the SSE feature to be supported by the processor.

The memory operand SHALL be a dword aligned to a 4-byte boundary; otherwise, an alignment check exception may occur depending on the CR0.AM setting. Since the MXCSR register controls floating-point environment settings, updating it may affect the behavior of subsequent SIMD instructions. Failure to properly initialize the MXCSR register before performing floating-point operations may lead to unexpected results regarding rounding modes and exception masking.