llvm dev - Feb 2016 - Hexagon, inline assembly and packetization

I'm not very clear on how exactly does Hexagon handle inline assembly
during packetization pass and afterwards. Say there are several
instructions in inline assembly. Will Hexagon split them and packetize
using dependencies? Will it create a packet for every instruction in the
inline assembly? Would anyone be able to provide any insights.

Help is greatly appreciated.

-- 
Rail Shafigulin
Software Engineer
Esencia Technologies
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20160217/c867f35d/attachment.html>

Packets when specified in assembly are delineated by curly braces.  If the
braces are omitted there is one instruction per packet.

 

One packet two instructions:

{ r0 = add(r0, r0)

  r1 = add(r1, r1) }

 

Two packets, one instruction each.

r0 = add(r0, r0)

r1 = add(r1, r1)

 

From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Rail
Shafigulin via llvm-dev
Sent: Wednesday, February 17, 2016 2:26 PM
To: llvm-dev
Subject: [llvm-dev] Hexagon, inline assembly and packetization

 

I'm not very clear on how exactly does Hexagon handle inline assembly during
packetization pass and afterwards. Say there are several instructions in inline
assembly. Will Hexagon split them and packetize using dependencies? Will it
create a packet for every instruction in the inline assembly? Would anyone be
able to provide any insights.

 

Help is greatly appreciated.



-- 

Rail Shafigulin

Software Engineer 
Esencia Technologies

-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20160217/6ec46925/attachment.html>

On 2/17/2016 2:25 PM, Rail Shafigulin via llvm-dev
wrote:
> I'm not very clear on how exactly does Hexagon handle inline assembly
> during packetization pass and afterwards. Say there are several
> instructions in inline assembly. Will Hexagon split them and packetize
> using dependencies? Will it create a packet for every instruction in the
> inline assembly? Would anyone be able to provide any insights.
Inline assembly is treated as a "solo" instruction in the packetizer.

-Krzysztof

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, 
hosted by The Linux Foundation