RFR (S): Specify offset of IC load in java_to_interp stub.

[Lindenmaier, Goetz]

Hi Chris, 

yes, there is no C1 on ppc.  
We do tiered compilation with a stripped C2.

Best regards,
  Goetz

-----Original Message-----
From: Christian Thalinger [mailto:christian.thalinger at oracle.com] 
Sent: Dienstag, 20. November 2012 22:19
To: Lindenmaier, Goetz
Cc: hotspot-compiler-dev at openjdk.java.net
Subject: Re: RFR (S): Specify offset of IC load in java_to_interp stub.


On Nov 20, 2012, at 3:08 AM, "Lindenmaier, Goetz" <goetz.lindenmaier at sap.com> wrote:

> Hi,
>  
> The class CompiledStaticCall must know the location of the IC load in the java_to_interp stub
> to update the IC  with NativeMovConstReg.  The current implementation assumes that
> the load is always the first instruction in the stub.  This is an artificial restriction. E.g.,
> it might be useful to load the constant pool address (MachConstantBase) before the
> IC load (as we do on PPC).
>  
> This change adds a constant specifying an offset from the beginning of the stub to
> the  IC load. The offset is platform specific and 0 on sparc and x86.
>  
> You can find the change here:
> http://cr.openjdk.java.net/~goetz/webrevs/webrev-IC_offset/

That should be fixed indeed.  

+#ifndef COMPILER2
+const int CompiledStaticCall::comp_to_int_load_offset = 0;

There is no C1 for PPC (sorry, I didn't check)?

-- Chris

>  
> or in our ppc port:
> http://hg.openjdk.java.net/ppc-aix-port/jdk7u/hotspot/rev/c6f9c897ea33
>  
> Thank you and best regards,
>   Goetz
>  
>  
>