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Index > Main > Please, help with SSE5 opcode encoding

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hopcode



Joined: 04 Mar 2008
Posts: 563
Location: Germany
hopcode
I am not fully deep inside SSE5, i have no time to study the DREX
byte Very Happy for 0F 24 / 0F 25, and i cannot encode it manually, at the moment
(if i do not mistake, fasm will support them in 1.70)

Have you sample of dumped bytecode for SSE5 to read, especially for
0F25 ?
According to AMD,
Code:
0F25 - OPCODE - MODRM - SIB - DREX -DISP1/2/4 - IMM8
    

it is to say, my question :
apart from the MODRM, are there other modification to the above instruction len ? (probably NOT)
It is to say, does the DREX byte to modifies/allows more immediates bytes or displacements in the istruction? (probably NOT)

Thanxs in advance,
hopcode

EDIT: forgotten 32bit possibly
Post 14 Jan 2010, 02:43
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MazeGen



Joined: 06 Oct 2003
Posts: 977
Location: Czechoslovakia
MazeGen
DREX merely replaces REX prefix, allows to declare one more XMM register and contains one of two operand configuration bits. So the answer is not and not.

EDIT: mod, move this topic to Main please
Post 14 Jan 2010, 10:10
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