the ARM and the Shark

[Gary Benson]

Robert Schuster wrote:
> Behold!
> 
> Starring:
> 
> LLVM 2.5
> OpenJDK Hotspot (Zero+Shark) from IcedTea 1.4.1
> 
> Special guest:
> 
> Beagleboard (armv7a -> Cortex A8 -> OMAP3530)
> 
> root at beagleboard:~# java -XX:+PrintCompilation HelloWorld
>   1       java.lang.String::equals (88 bytes)
> Hello World!
> 
> No crash here. :)
> 
> root at beagleboard:~# ./azureus
>   1       java.lang.String::equals (88 bytes)
>   2       java.lang.String::hashCode (60 bytes)
>   3       java.lang.String::indexOf (151 bytes)
> file:/usr/share/java/Azureus2.jar ; file:/usr/share/java/swt-gtk-3.4.jar
> ;   4file:/home/root/
>   !    sun.nio.cs.US_ASCII$Encoder::encodeArrayLoop (279 bytes)
>   5       java.lang.String::lastIndexOf (156 bytes)
>   6       java.lang.String::charAt (33 bytes)
>   7       java.util.Properties$LineReader::readLine (452 bytes)
>   8       java.util.Properties::loadConvert (505 bytes)
> Cannot yet select: 0x8ed18: i32,ch = AtomicCmpSwap 0x8e2f4, 0x8ea70,
> 0x8eeb0, 0xdf2a8 <0x11844c:0> <volatile> alignment=4
> Aborted
> 
> Now is that cool or is that cool? :)

That is cool, congratulations! :D

> The error message that causes the VM to crash when running Azureus
> is caused by LLVM not providing ways to implement a certain atomic
> compare and swap function (the so-called llvm.atomic.cmp.swap.i32
> intrinsic).
> 
> Xerxes Ranby and me are currently fight^H^H^H^H^H trying to
> understand how to implement this in LLVM.
> 
> From the looks of it the MIPS backend of LLVM also does not have
> atomic function support.

LLVM didn't have it on PowerPC either until I added it.  Or, rather,
there was partial support, but it was unusable so I had to replace it.
The final patch is at http://markmail.org/message/zm5zwxlr65nacpts,
which might help you to find the corresponding ARM files that need
altering.

Cheers,
Gary

-- 
http://gbenson.net/