llvm dev - Sep 2011 - [LLVMdev] The right option combination to compile into ARM/Thumb2 code.

Hello,

I'm trying to convince llc to compile into thumb2 ISA on ARMv7. I'm
using:

-march=thumb -mattr=v7,thumb2,vfp3

but llc complains about this with:

llc: error: invalid target 'thumb -mattr=v7,thumb2,vfp3'

I'm using LLVM from Aug 29 2011. To me the set of options looks sane so 
I'd like to ask what's wrong with this.

Thanks!
Karel

Hi Karel,

It actually looks like the argument parser has parsed "thumb
-mattr=v7,thumb2,vfp3" as the full argument to "-march=".
Strange.

The easiest way to get what you want is probably "-mtriple thumbv7--".
v7 has Thumb2 enabled and VFPv3 (along with NEON) by default.

Cheers,

James
________________________________________
From: llvmdev-bounces at cs.uiuc.edu [llvmdev-bounces at cs.uiuc.edu] On Behalf
Of Karel Gardas [karel.gardas at centrum.cz]
Sent: 03 September 2011 08:47
To: LLVM Developers Mailing List
Subject: [LLVMdev] The right option combination to compile into ARM/Thumb2     
code.

Hello,

I'm trying to convince llc to compile into thumb2 ISA on ARMv7. I'm
using:

-march=thumb -mattr=v7,thumb2,vfp3

but llc complains about this with:

llc: error: invalid target 'thumb -mattr=v7,thumb2,vfp3'

I'm using LLVM from Aug 29 2011. To me the set of options looks sane so
I'd like to ask what's wrong with this.

Thanks!
Karel
_______________________________________________
LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev


-- IMPORTANT NOTICE: The contents of this email and any attachments are
confidential and may also be privileged. If you are not the intended recipient,
please notify the sender immediately and do not disclose the contents to any
other person, use it for any purpose, or store or copy the information in any
medium.  Thank you.

Hi James,

On 09/ 3/11 10:46 AM, James Molloy wrote:
> Hi Karel,
>
> It actually looks like the argument parser has parsed "thumb
-mattr=v7,thumb2,vfp3" as the full argument to "-march=".
Strange.
thanks a lot for this remark. It actually solved my issue. It was caused 
by me telling GHC to pass all those params by using one -optlc parameter 
but this indeed results in llc receiving whole this string as one 
parameter. So instead of wrong:

-optlc="-march=thumb -mattr=v7,thumb2,vfp3"

I need to use:

-optlc=-march=thumb -optlc=-mattr=v7,thumb2,vfp3

where -optlc passes its argument to llc command.

Thanks!
Karel