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• Decoding-and-spec-utils

Prefix-modrm-sib-decoding

Decoding utilities for the prefixes, ModR/M, and SIB bytes

Legacy Prefix Decoding

Array *one-byte-prefixes-group-code-info-ar* is used for the efficient lookup of prefix group code information from the one-byte opcode map; see legacy-prefixes-decoding and opcode-maps.

Picking Mandatory Prefixes

See mandatory-prefixes-computation and instructions-with-mandatory-prefixes for details.

ModR/M and VEX Decoding

Arrays are created for the efficient lookup of modr/m-related information from the opcode maps. See ModR/M-decoding.

SIB Detecting and Decoding

See SIB-decoding for details.

Subtopics

Modr/m-decoding

Functions to detect and decode ModR/M bytes

Mandatory-prefixes-computation

Picking a mandatory prefix

Modr/m-detection

Utilities to detect which opcodes need a ModR/M byte

Legacy-prefixes-decoding

Functions to detect and decode legacy prefixes

Compute-mandatory-prefix-for-three-byte-opcode

Three-byte opcodes: picks the appropriate SIMD prefix as the mandatory prefix, if applicable

64-bit-compute-mandatory-prefix-for-0f-3a-three-byte-opcode

64-bit-compute-mandatory-prefix-for-0f-38-three-byte-opcode

32-bit-compute-mandatory-prefix-for-0f-3a-three-byte-opcode

32-bit-compute-mandatory-prefix-for-0f-38-three-byte-opcode

64-bit-compute-mandatory-prefix-for-two-byte-opcode

32-bit-compute-mandatory-prefix-for-two-byte-opcode

Instructions-with-mandatory-prefixes

Based off opcode-maps, pre-computing the opcodes that have a valid instruction corresponding to the following prefixes: :NO-PREFIX :66 :F3 :F2.

Compute-mandatory-prefix-for-0f-3a-three-byte-opcode

Compute-mandatory-prefix-for-0f-38-three-byte-opcode

Compute-mandatory-prefix-for-two-byte-opcode