Author Topic: blsi  (Read 2380 times)

Offline suncowiam

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blsi
« on: September 22, 2023, 09:52:01 PM »
Hi,

I see BLSI listed in the following document:
https://redirect.cs.umbc.edu/~chang/cs313.s13/nasmdoc/nasmdoc.pdf

However, when I try to compile an asm file with blsi op, I get the following:
blsi.asm:15: error: parser: instruction expected

The line:
    blsi rax, rbx

Am I missing something or nasm doesn't support this instruction?

Thanks

Offline debs3759

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Re: blsi
« Reply #1 on: September 22, 2023, 10:54:00 PM »
Hi,

I see BLSI listed in the following document:
https://redirect.cs.umbc.edu/~chang/cs313.s13/nasmdoc/nasmdoc.pdf

However, when I try to compile an asm file with blsi op, I get the following:
blsi.asm:15: error: parser: instruction expected

The line:
    blsi rax, rbx

Am I missing something or nasm doesn't support this instruction?

Thanks

It's listed as a future opcode, so isn't supported yet. I don't know which processor family supports (or will support) it, so you may need to wait a while for someone to add the BM11 and BM12 instruction sets.
My graphics card database: www.gpuzoo.com

Offline Frank Kotler

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Re: blsi
« Reply #2 on: September 22, 2023, 10:56:54 PM »
Code: [Select]
bits 64
blsi eax, ebx
...seems to work...
?
Hi Debs...?

Best,
Frank


Offline Frank Kotler

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Re: blsi
« Reply #3 on: September 22, 2023, 11:10:02 PM »
I should mention version!
2.14.02

Best,
Frank


Offline debs3759

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Re: blsi
« Reply #4 on: September 23, 2023, 01:53:08 AM »
Code: [Select]
bits 64
blsi eax, ebx
...seems to work...
?
Hi Debs...?

Best,
Frank

Ah, the linked version of the manual is version 2.10.04, so maybe the instructions were added since then. I haven't looked at programming manuals for quite some time, and most code I've written will run of a 386 or 486. I really need to do some more coding, and learn how to use more than basic x86 instructions :)
My graphics card database: www.gpuzoo.com

Offline Frank Kotler

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Re: blsi
« Reply #5 on: September 23, 2023, 04:18:53 AM »
I dunno. I had a pretty good grasp of 8086/8088 code at one time. Newer code not so much. IIdid  didn't know blsi, but rather than post, "I dunno' I decided to fool with it and came up with that. 64 bit regs apparently DON'T work.

I dunno,
Frank



Offline fredericopissarra

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Re: blsi
« Reply #6 on: September 26, 2023, 07:02:28 PM »
I believe BLSI instruction was introduced in Haswell microarchitecture. It is from BMI1 instruction set (VEX prefix) - so it is listed in Intel SDM. Of course old NASM versions don't have support for it.

Offline Frank Kotler

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Re: blsi
« Reply #7 on: September 26, 2023, 10:57:25 PM »
Right!
I wonder how suncowiam is making out with it?

Best,
Frank