[fpc-devel] x86ins.dat

[Florian Klämpfl]

Am 07.01.2012 15:19, schrieb Torsten:
> Hi,
> 
> Am 07.01.2012 15:01, schrieb Sergei Gorelkin:
>> 07.01.2012 16:53, tgrundke пишет:
>>> Hi,
>>>
>>> i am working on the AVX-support for the fp-compiler.
>>>
>>> Some AVX-assembler instructions have 4 operant e.g.
>>>
>>>
>>> VBLENDVPD xmm1, xmm2, xmm3/m128, xmm4
>>>
>>>
>>>
>>> INTEL Def.
>>>
>>> 3.1.1.2 Opcode Column in the Instruction Summary Table (Instructions
>>> with VEX prefix)
>>>
>>> /is4: An 8-bit immediate byte is present containing a source register
>>> specifier in
>>> imm[7:4] and instruction-specific payload in imm[3:0].
>>>
>>>
>>>
>>> I need a idea, how can i encode (in file x86ins.dat)  the 4th operant.
>>>
>>> My idea:
>>>
>>> new flag \77 =>> 4th operand is coded in bit 4-7 and the follow byte
>>> define the bits 0-3
>>> e.g.
>>>
>>> [VBLENDVPD]
>>> (Ch_All, Ch_None, Ch_None)
>>> xmmreg,xmmreg,xmmrm,xmmreg                 
>>> \361\362\372\1\x4B\75\120\77\x00
>>> AVX,SANDYBRIDGE
>>>
>>> \ 361 = prefix 066h for SSE instruction
>>> \ 362 = new flag VEX (starting with 0xC5 or 0xC4)
>>> \ 372 = new flag VEX-CODE include prefix 0x0F3A
>>> \ 75   = VEX-BYTE contains operand no. 2
>>> \ 120 = operands 1 and 3 encoded in MODRM-Byte
>>> \ 77   = immediate byte (bit 4-7) contains 4th operand
>>> \ 00   = immediate byte (bit 0-3) = 0
>>>
>>>
>>> i look forward to comments.
>>>
>> IMHO, since fpc's x86 assembler is based on NASM, the best way would
>> be to stay as close to NASM format as possible.
>>
> is not simple.
> 
> Nasm: VBLENDVPD    ymmreg,ymmreg*,ymmrm256,ymmreg    [rvms:   
> vex.nds.256.66.0f3a.w0 4b /r /is4]    AVX,SANDYBRIDGE
>             VADDPS        xmmreg,xmmreg*,xmmrm128                      
> [rvm:    vex.nds.128.0f 58 /r]            AVX,SANDYBRIDGE
> 
> fpc       VBLENDVPD  xmmreg,xmmreg,xmmrm,xmmreg  
> \361\362\372\1\x4B\75\120\77\x00
>             VADDPS          Xmmreg,xmmreg,xmmrm                 
> \362\370\1\x58\75\120                AVX,SANDYBRIDGE

Nasm supports also both formats. IMO the main issue is that nasm is not
gpl anymore but bsd.