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Copy all bits of the source argument, then clear the lowest set bit. Equivalent to dst = (src-1) AND src: BMI2 Bit Manipulation Instruction Set 2: BZHI ra,r/m,rb: VEX.LZ.0F38 F5 /r: Zero out high-order bits in r/m starting from the bit position specified in rb, then write result to rd. Equivalent to ra = r/m AND NOT(-1 << rb[7:0]) Haswell ...
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.
While what these instructions do is similar to bit level gather-scatter SIMD instructions, PDEP and PEXT instructions (like the rest of the BMI instruction sets) operate on general-purpose registers. [12] The instructions are available in 32-bit and 64-bit versions. An example using arbitrary source and selector in 32-bit mode is:
Instruction set extensions that have been added to the x86 instruction set in order to support hardware virtualization.These extensions provide instructions for entering and leaving a virtualized execution context and for loading virtual-machine control structures (VMCSs), which hold the state of the guest and host, along with fields which control processor behavior within the virtual machine.
The implemented CPU instructions should by default not support a wide set of inputs, so this typically means an 8-bit or 16-bit CPU. If a CPU has an NX bit, it is more likely to be viewed as being a complex instruction set computer (CISC) or reduced instruction set computer (RISC). MISC chips typically lack hardware memory protection of any ...
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: Multiply the high half of the destination register by the low half of the source operand. PCLMULLQHQDQ ...
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 1999. It introduces two new operating modes: 64-bit mode and compatibility mode, along with a new four-level paging mechanism.
AMD's 64-bit extension to the original instruction set make relatively few changes to 32-bit addressing, with the most significant being that in long mode, 64-bit addressing is the default. 64-bit registers (RAX, RBX, RCX, etc.) are used rather than 32-bit registers for address computation. The displacement is not widened to 64 bits; MOD=11 ...