RFR: 8301995: Move invokedynamic resolution information out of ConstantPoolCacheEntry

[Richard Reingruber]

On Tue, 7 Mar 2023 13:30:50 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> The current structure used to store the resolution information for invokedynamic, ConstantPoolCacheEntry, is difficult to interpret due to its ambigious fields f1 and f2. This structure can hold information for fields, methods, and invokedynamics and each of its fields can hold different types of values depending on the entry. 
>> 
>> This enhancement proposes a new structure to exclusively contain invokedynamic information in a manner that is easy to interpret and easy to extend.  Resolved invokedynamic entries will be stored in an array in the constant pool cache and the operand of the invokedynamic bytecode will be rewritten to be the index into this array.
>> 
>> Any areas that previously accessed invokedynamic data from ConstantPoolCacheEntry will be replaced with accesses to this new array and structure. Verified with tier1-9 tests.
>> 
>> The PPC was provided by @reinrich and the RISCV port was provided by @DingliZhang and @zifeihan.
>> 
>> This change supports the following platforms: x86, aarch64, PPC, and RISCV
>
> src/hotspot/cpu/ppc/templateTable_ppc_64.cpp line 53:
> 
>> 51: 
>> 52: #undef __
>> 53: #define __ Disassembler::hook<InterpreterMacroAssembler>(__FILE__, __LINE__, _masm)->
> 
> What is this?  Is this something useful for debugging the template interpreter?  Probably doesn't belong with this change but might be nice to have (?) @reinrich

Yes this is really useful when debugging the template interpreter. It annotates the disassembly with the generator source code. It helped tracking down a bug in the ppc part oft this pr. Other platforms have it too.

Example:

invokedynamic  186 invokedynamic  [0x00003fff80075a00, 0x00003fff80075dc8]  968 bytes

--------------------------------------------------------------------------------
  0x00003fff80075a00:   std     r17,0(r15)                  ;;@FILE: src/hotspot/cpu/ppc/templateInterpreterGenerator_ppc.cpp
                                                            ;; 2185:   aep = __ pc();  __ push_ptr();  __ b(L);
  0x00003fff80075a04:   addi    r15,r15,-8
  0x00003fff80075a08:   b       0x00003fff80075a40          ;; 2185:   aep = __ pc();  __ push_ptr();  __ b(L);
  0x00003fff80075a0c:   stfs    f15,0(r15)                  ;; 2186:   fep = __ pc();  __ push_f();    __ b(L);
  0x00003fff80075a10:   addi    r15,r15,-8
  0x00003fff80075a14:   b       0x00003fff80075a40          ;; 2186:   fep = __ pc();  __ push_f();    __ b(L);
  0x00003fff80075a18:   stfd    f15,-8(r15)                 ;; 2187:   dep = __ pc();  __ push_d();    __ b(L);
  0x00003fff80075a1c:   addi    r15,r15,-16
  0x00003fff80075a20:   b       0x00003fff80075a40          ;; 2187:   dep = __ pc();  __ push_d();    __ b(L);
  0x00003fff80075a24:   li      r0,0                        ;; 2188:   lep = __ pc();  __ push_l();    __ b(L);
  0x00003fff80075a28:   std     r0,0(r15)
  0x00003fff80075a2c:   std     r17,-8(r15)
  0x00003fff80075a30:   addi    r15,r15,-16
  0x00003fff80075a34:   b       0x00003fff80075a40          ;; 2188:   lep = __ pc();  __ push_l();    __ b(L);
  0x00003fff80075a38:   stw     r17,0(r15)                  ;; 2189:   __ align(32, 12, 24); // align L
                                                            ;; 2191:   iep = __ pc();  __ push_i();
  0x00003fff80075a3c:   addi    r15,r15,-8
  0x00003fff80075a40:   li      r21,1                       ;; 2192:   vep = __ pc();
                                                            ;; 2193:   __ bind(L);
                                                            ;;@FILE: src/hotspot/share/interpreter/templateInterpreterGenerator.cpp
                                                            ;;  366:   __ verify_FPU(1, t->tos_in());
                                                            ;;@FILE: src/hotspot/cpu/ppc/templateTable_ppc_64.cpp
                                                            ;; 2293:   __ load_resolved_indy_entry(cache, index);
  0x00003fff80075a44:   lwax    r21,r14,r21
  0x00003fff80075a48:   nand    r21,r21,r21
  0x00003fff80075a4c:   ld      r31,40(r27)
  0x00003fff80075a50:   rldicr  r21,r21,4,59
  0x00003fff80075a54:   addi    r21,r21,8
  0x00003fff80075a58:   add     r31,r31,r21
  0x00003fff80075a5c:   ld      r22,0(r31)                  ;; 2294:   __ ld_ptr(method, in_bytes(ResolvedIndyEntry::method_offset()), cache);
  0x00003fff80075a60:   cmpdi   r22,0                       ;; 2297:   __ cmpdi(CCR0, method, 0);
  0x00003fff80075a64:   bne-    0x00003fff80075b94          ;; 2298:   __ bne(CCR0, resolved);,bo=0b00100[no_hint]
  0x00003fff80075a68:   li      r4,186                      ;; 2304:   __ li(R4_ARG2, code);
  0x00003fff80075a6c:   ld      r11,0(r1)                   ;; 2305:   __ call_VM(noreg, entry, R4_ARG2, true);

-------------

PR: https://git.openjdk.org/jdk/pull/12778