What Do You Think? JDK-8213084: Rework and enhance Print[Opto]Assembly output

Schmidt, Lutz lutz.schmidt at sap.com
Fri Nov 30 16:13:16 UTC 2018


Sorry, 
hit the wrong reply button. Wasn't meant to be hidden communication.
Regards,
Lutz

On 30.11.18, 15:51, "Schmidt, Lutz" <lutz.schmidt at sap.com> wrote:

    Hi Andrew, 
    
    I assume you read my response to Andrew Haley as well. I will therefore
    restrict my comments here on what to do if no hsdis.so is available. 
    
    I can't comment on your customers. Ours are extremely reluctant when it
    comes to adding libraries of "unknown origin" to their landscape. For us
    it boils down to getting a hex byte dump or nothing.
    
    I agree, manually disassembling the hex dump isn't a sexy task. We have 
    a homegrown tool for that. It could be contributed to OpenJDK, but as a
    separate enhancement. 
    
    Thank you, 
    Lutz
    
    On 30.11.18, 11:30, "Andrew Dinn" <adinn at redhat.com> wrote:
    
        I am entirely in agreement with Andrew Haley:
        
        The blank lines in the original format are critical to conspicuity of
        independent groups of information. Gestalt matters.
        
        The additional detail (keywords, brackets offset, insn bytes) add almost
        zero /useful/ information, effectively blotting the original signal with
        noise.
        
        Also, I'm also dubious over the utility of providing a hex byte dump of
        the code when no hsdis.so is available. I say that having written a
        simulator for AArch64 (including, therefore, a decode unit) and coded &
        debugged a lot of AArch4 and x86 assembler and, occasionally, machine
        code. So, I'm probably one of your most promising potential customers
        for such a feature and I'm (at best) lukewarm.
        
        I'll allow that there /may/ be situations where one could arrange for
        PrintAsssembly to be enabled on a java command line but could not
        arrange for an hsdis.so to be installed in the LD_LIBRARY_PATH yet I'm
        struggling to think of one. Faced with the task of decoding the hex I'd
        much rather spend time working on whatever problems were involved in
        building and/or installing the library.
        
        regards,
        
        
        Andrew Dinn
        -----------
        Senior Principal Software Engineer
        Red Hat UK Ltd
        Registered in England and Wales under Company Registration No. 03798903
        Directors: Michael Cunningham, Michael ("Mike") O'Neill, Eric Shander
        
    
    



More information about the hotspot-compiler-dev mailing list