NASM - The Netwide Assembler

NASM Forum => Programming with NASM => Topic started by: suncowiam on September 22, 2023, 09:52:01 PM

Title: blsi
Post by: suncowiam 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

Title: Re: blsi
Post by: debs3759 on September 22, 2023, 10:54:00 PM

Quote from: suncowiam 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

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.

Title: Re: blsi
Post by: Frank Kotler on September 22, 2023, 10:56:54 PM

Code: [Select]

bits 64
blsi eax, ebx
...seems to work...
?
Hi Debs...?

Best,
Frank

Title: Re: blsi
Post by: Frank Kotler on September 22, 2023, 11:10:02 PM

I should mention version!
2.14.02

Best,
Frank

Title: Re: blsi
Post by: debs3759 on September 23, 2023, 01:53:08 AM

Quote from: Frank Kotler on September 22, 2023, 10:56:54 PM

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 :)

Title: Re: blsi
Post by: Frank Kotler 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

Title: Re: blsi
Post by: fredericopissarra 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.

Title: Re: blsi
Post by: Frank Kotler on September 26, 2023, 10:57:25 PM

Right!
I wonder how suncowiam is making out with it?

Best,
Frank