The XOP (eXtended Operations[1]) instruction set, announced by AMD on May 1, 2009, is an extension to the 128-bit SSE core instructions in the x86 and AMD64 instruction set for the Bulldozer processor core, which was released on October 12, 2011.[2] However AMD removed support for XOP from Zen (microarchitecture) onward.[3]
The XOP instruction set contains several different types of vector instructions since it was originally intended as a major upgrade to SSE. Most of the instructions are integer instructions, but it also contains floating point permutation and floating point fraction extraction instructions. See the index for a list of instruction types.
- ^ Cite error: The named reference
Striking-a-balancewas invoked but never defined (see the help page). - ^ AMD64 Architecture Programmer's Manual Volume 6: 128-Bit and 256-Bit XOP, FMA4 and CVT16 Instructions (PDF), AMD, May 1, 2009
- ^ Michael Larabel (March 3, 2017). "The Impact Of GCC Zen Compiler Tuning On AMD Ryzen Performance". Phoronix.
But with Zen being a clean-sheet design, there are some instruction set extensions found in Bulldozer processors not found in Zen/znver1. Those no longer present include FMA4 and XOP.