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  1. Developer's manual: 0x66 0xF2 instruction prefixes

    Intel® AVX introduces a new prefix, referred to as VEX, in the Intel® 64 and ... of REX prefix functionality. compaction of SIMD prefix functionality and escape byte  ...

  2. Possible XED Decode Bug (from Pin rev 65163)

    Aug 22, 2014 ... The problem appears to be that XED will more than one REX prefix and generate an instruction. For example: 41-40-26-E8-77-70-C5-A2

  3. XED2: XED2 User Guide - Wed Jan 2 23:48:56 2013

    Jan 2, 2013 ... REX prefix byte. Only in 64b mode. It has 4 1-bit fields: W, R, X, and B. The W bit modifies the operation width. The R, X and B fields extend the ...

  4. question on avx instruction encoding

    so any instruction that can be encoded with a two byte vex prefix can be encoded with a ... In SSE, the 4th bit came from the REX prefix fields.

  5. XED2: XED2 User Guide - Wed Aug 8 00:23:42 2012

    Aug 8, 2012 ... There is only one rex prefix that is used; 00111 but any rex-s that are mixed-in with the legacy prefixes are 00112 ignored! We must count them.

  6. Developer's manual: 0x66 0xF2 instruction prefixes

    3EH—DS segment override prefix (use with any branch instruction is ... prefixes ( exception to this is discussed in Section 2.2.1, “REX Prefixes”).

  7. XED: xed-error-enum.h File Reference

    Jan 21, 2015 ... XED_ERROR_BAD_REX_PREFIX, A REX prefix was found where none is allowed. XED_ERROR_BAD_EVEX_UBIT, An illegal value for the ...

  8. XED2: XED2 User Guide - Wed Jan 2 23:48:57 2013

    Jan 2, 2013 ... True if the instruction as a F3 REP prefix (used for opcode refining, for rep for string .... This instruction has a REX prefix with the W bit set.

  9. XED: xed-operand-values-interface.h File Reference

    Dec 26, 2013 ... True if the instruction as a F3 REP prefix (used for opcode refining, for rep for string .... This instruction has a REX prefix with the W bit set.

  10. Introduction to x64 Assembly | Intel® Software

    Mar 19, 2012 ... There are odd limitations accessing the byte registers due to coding issues in the REX opcode prefix used for the new registers: an instruction ...

  11. Intel® Software Development Emulator | Intel® Software

    Jun 15, 2012 ... *rex_prefix Instructions with a REX prefix (includes the following 4 cases). REX prefixes can be sued without any of the following 4 bits set as ...

  12. Google VP9 Optimization | Intel® Software

    Mar 25, 2016 ... Quite often a 4th prefix is added when any of the upper 8 xmm ... and “ pmaddubsw xmm1, xmm16 ” will add the REX prefix – “66 41 0F 38 04 ...

  13. Details of Intel® Advanced Vector Extensions Intrinsics | Intel ...

    Instruction encoding format using a new prefix (referred to as VEX) to provide ... vector lengths, compaction of legacy SIMD prefixes and REX functionality.

  14. Intel(R) Advanced Vector Extensions Programming Reference

    1-3. 1.3.3. VEX Prefix Instruction Encoding Support . .... YMM State, VEX Prefix and Supported Operating Modes . ... 4-2. 4.1.3. VEX and the REX prefix .

  15. The structure of ModR/M byte

    Aug 17, 2010 ... ... using register extension field in the MOD R/M byte are not encodable in 64-bit mode because the opcodes are treated as REX prefixes.

  16. Branch instructions in 64 bit mode

    Aug 3, 2010 ... These instructions update the 64-bit RIP without the need for a REX operand-size prefix.The following aspects of near branches are controlled ...

  17. Intel® AVX-512 instructions | Intel® Software

    Jul 23, 2013 ... Intel AVX instructions use the VEX prefix while Intel AVX-512 .... is missing B' and X' bits to extend the B and X bits of the REX prefix. So we

  18. Behavior of IMUL regarding SF

    Apr 27, 2015 ... My program uses the second form (48 0f af c1, 48 being the REX.W prefix). I know that the one-operand form places its result in D and A and ...

  19. Intel® X86 Encoder Decoder

    by Mark Charney. 2016-02-02. Introduction. Intel® XED is an acronym for Intel® X86 Encoder Decoder. The latter part is pronounced like the (British) English "z".

  20. Intel® Xeon Phi™ Core Micro-architecture | Intel® Software

    May 31, 2013 ... At the D0 stage we do the fast prefix decoding where a given set of prefixes .... REX prefix for integer instructions for 64-bit code and 0f prefix.

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