RFR(S) 8204267 - Generate comments in -XX:+PrintInterpreter to link to source code

[Ioi Lam]

Hi,


Since there's interest for this patch, I've finished it for the x86 port:

https://bugs.openjdk.java.net/browse/JDK-8204267
http://cr.openjdk.java.net/~iklam/jdk12/8204267-print-interpreter-comments.v001/

You can see a sample at

http://cr.openjdk.java.net/~iklam/jdk12/8204267-print-interpreter-comments.v001/sample.txt

Incorporating this to other CPU ports should be pretty straight forward. 
You just
need to do something like:

-#define __ _masm->
+#define __ Disassembler::hook<MacroAssembler>(__FILE__, __LINE__, _masm)->

I'll leave it to other CPU port maintainers.

I am testing with hs_tier{1,2}.

Thanks

- Ioi


On 6/4/18 12:12 AM, Ioi Lam wrote:
> Hi Folks,
>
> I've found it very hard to understand the assembler code printed by 
> -XX:+PrintInterpreter. Since the C++ source code that generates the 
> interpreter is fairly well documented, it might be a good idea to 
> print out the source code along with the assembler code.
>
> I've done a quick proof-of-concept by hacking the "__" macro that's 
> used throughout the CPU-dependent sources.
>
> Please let me know if you think this is worth doing. If so, I will try 
> to finish it up and post a real RFR.
>
> Thanks
> - Ioi
>
>
> https://bugs.openjdk.java.net/browse/JDK-8204267
> http://cr.openjdk.java.net/~iklam/misc/8204267-print-interpreter-comments.v00 
>
> http://cr.openjdk.java.net/~iklam/misc/8204267-print-interpreter-comments.v00/hs_interp.S 
>
>
> Here are some examples (if the mailer screws up the long lines, please 
> click the above link):
>
> ifeq  153 ifeq  [0x00007f830cc93da0, 0x00007f830cc941c0] 1056 bytes
>
> mov    (%rsp),%eax
> add    $0x8,%rsp
> test   %eax,%eax           ;; 2353:   __ testl(rax, rax);
> jne    0x00007f830cc94177  ;; 2354:   __ jcc(j_not(cc), not_taken);
> mov    -0x18(%rbp),%rcx    ;; 2120:   __ get_method(rcx); // rcx holds 
> method
> mov    -0x28(%rbp),%rax    ;; 2121:   __ profile_taken_branch(rax, 
> rbx); // rax holds updated MDP, rbx
> test   %rax,%rax
> je     0x00007f830cc93dd8
> mov    0x8(%rax),%rbx
> add    $0x1,%rbx
> sbb    $0x0,%rbx
> mov    %rbx,0x8(%rax)
> add    0x10(%rax),%rax
> mov    %rax,-0x28(%rbp)
> movswl 0x1(%r13),%edx      ;; 2133:     __ load_signed_short(rdx, 
> at_bcp(1));
> bswap  %edx                ;; 2135:   __ bswapl(rdx);
> sar    $0x10,%edx          ;; 2138:     __ sarl(rdx, 16);
> movslq %edx,%rdx           ;; 2140:   LP64_ONLY(__ movl2ptr(rdx, rdx));
> add    %rdx,%r13           ;; 2164:   __ addptr(rbcp, rdx);
> test   %edx,%edx           ;; 2179:     __ testl(rdx, 
> rdx);             // check if forward or backward branch
> jns    0x00007f830cc93eec  ;; 2180:     __ jcc(Assembler::positive, 
> dispatch); // count only if backward branch
> mov    0x18(%rcx),%rax     ;; 2184:     __ movptr(rax, Address(rcx, 
> Method::method_counters_offset()));
> test   %rax,%rax           ;; 2185:     __ testptr(rax, rax);
> jne    0x00007f830cc93ead  ;; 2186:     __ jcc(Assembler::notZero, 
> has_counters);
> push   %rdx                ;; 2187:     __ push(rdx);
> push   %rcx                ;; 2188:     __ push(rcx);
> callq  0x00007f830cc93e09  ;; 2189:     __ call_VM(noreg, 
> CAST_FROM_FN_PTR(address, InterpreterRuntime::build_method_counters),
>