Search results
Results from the WOW.Com Content Network
The x86 instruction set refers to the set of instructions that x86-compatible microprocessors support. The instructions are usually part of an executable program, often stored as a computer file and executed on the processor. The x86 instruction set has been extended several times, introducing wider registers and datatypes as well as new ...
AMD Opteron, the first CPU to introduce the x86-64 extensions in April 2003 The five-volume set of the x86-64 Architecture Programmer's Manual, as published and distributed by AMD in 2002. x86-64 (also known as x64, x86_64, AMD64, and Intel 64) [note 1] is a 64-bit extension of the x86 instruction set architecture first announced in
The x86 instruction set has several times been extended with SIMD (Single instruction, multiple data) instruction set extensions.These extensions, starting from the MMX instruction set extension introduced with Pentium MMX in 1997, typically define sets of wide registers and instructions that subdivide these registers into fixed-size lanes and perform a computation for each lane in parallel.
The x86 instruction set includes string load, store, move, scan and compare instructions (lods, stos, movs, scas and cmps) which perform each operation to a specified size (b for 8-bit byte, w for 16-bit word, d for 32-bit double word) then increments/decrements (depending on DF, direction flag) the implicit address register (si for lods, di ...
The REX prefix provides additional space for encoding 64-bit addressing modes and additional registers present in the x86-64 architecture. Bit-field W changes the operand size to 64 bits, R expands reg to 4 bits, B expands r/m (or opreg in the few opcodes that encode the register in the 3 lowest opcode bits, such as "POP reg"), and X and B expand index and base in the SIB byte.
Instruction Opcode Description PCLMULQDQ xmm1,xmm2,imm8: 66 0F 3A 44 /r ib: Perform a carry-less multiplication of two 64-bit polynomials over the finite field GF(2 k). PCLMULLQLQDQ xmm1,xmm2/m128: 66 0F 3A 44 /r 00: Multiply the low halves of the two 128-bit operands. PCLMULHQLQDQ xmm1,xmm2/m128: 66 0F 3A 44 /r 01
Added important powerful new instructions, SSE4.2. Westmere: 32 nm shrink of the Nehalem microarchitecture with several new features. Sandy Bridge 32 nm microarchitecture, released January 9, 2011. Formerly called Gesher but renamed in 2007. [2] First x86 to introduce 256 bit AVX instruction set and implementation of YMM registers.
The FMA instruction set is an extension to the 128 and 256-bit Streaming SIMD Extensions instructions in the x86 microprocessor instruction set to perform fused multiply–add (FMA) operations. [1] There are two variants: FMA4 is supported in AMD processors starting with the Bulldozer architecture. FMA4 was performed in hardware before FMA3 was.