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SHA256MSG1

SHA256MSG1 performs a SHA-256 message schedule update. It computes the sum of the specified source register, a rotated version of another register, and a third register, then stores the result in the destination register.

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

DO NOT support LOCK

The instruction is only available when the SHA extensions are supported by the processor. It operates exclusively on XMM registers.

The instruction requires the use of 128-bit XMM registers; attempting to use other register types SHALL result in an invalid operand. Ensure that the CPUID.0x00000001:ECX.bit26 (SHA) flag is set before execution to avoid an illegal instruction exception.