src/hotspot/cpu/aarch64/jniFastGetField_aarch64.cpp

rev 50376 : [mq]: JDK-8203172.patch

*** 89,121 ****
  
    __ lsr(roffset, c_rarg2, 2);                // offset
  
    assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
    speculative_load_pclist[count] = __ pc();   // Used by the segfault handler
    switch (type) {
!     case T_BOOLEAN: __ ldrb    (result, Address(robj, roffset)); break;
!     case T_BYTE:    __ ldrsb   (result, Address(robj, roffset)); break;
!     case T_CHAR:    __ ldrh    (result, Address(robj, roffset)); break;
!     case T_SHORT:   __ ldrsh   (result, Address(robj, roffset)); break;
!     case T_FLOAT:   __ ldrw    (result, Address(robj, roffset)); break;
!     case T_INT:     __ ldrsw   (result, Address(robj, roffset)); break;
      case T_DOUBLE:
!     case T_LONG:    __ ldr     (result, Address(robj, roffset)); break;
!     default:        ShouldNotReachHere();
!   }
! 
    // counter_addr is address dependent on result.
    __ eor(rcounter_addr, rcounter_addr, result);
    __ eor(rcounter_addr, rcounter_addr, result);
    __ ldrw(rscratch1, safepoint_counter_addr);
    __ cmpw(rcounter, rscratch1);
    __ br (Assembler::NE, slow);
  
    switch (type) {
!     case T_FLOAT:   __ fmovs(v0, result); break;
!     case T_DOUBLE:  __ fmovd(v0, result); break;
!     default:        __ mov(r0, result);   break;
    }
    __ ret(lr);
  
    slowcase_entry_pclist[count++] = __ pc();
    __ bind(slow);
--- 89,126 ----
  
    __ lsr(roffset, c_rarg2, 2);                // offset
  
    assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
    speculative_load_pclist[count] = __ pc();   // Used by the segfault handler
+ 
+   // Ensure that field has finished loading before loading the safepoint_counter.
+   // We must not load into r0 yet. It's also c_rarg0 and would clobber the JNIEnv* pointer.
    switch (type) {
!     case T_FLOAT:
      case T_DOUBLE:
!       __ access_load_at(type, IN_HEAP, noreg /* tos: r0/v0 */, Address(robj, roffset), noreg, noreg);
!       __ membar(MacroAssembler::LoadLoad);
!       break;
!     default:
!       __ access_load_at(type, IN_HEAP, result, Address(robj, roffset), noreg, noreg);
        // counter_addr is address dependent on result.
        __ eor(rcounter_addr, rcounter_addr, result);
        __ eor(rcounter_addr, rcounter_addr, result);
+   }
+ 
    __ ldrw(rscratch1, safepoint_counter_addr);
    __ cmpw(rcounter, rscratch1);
    __ br (Assembler::NE, slow);
  
    switch (type) {
!     case T_FLOAT:
!     case T_DOUBLE:
!       // Result is already in v0. Nothing to do.
!       break;
!     default:
!       // Move result over to r0.
!       __ mov(r0, result);
    }
    __ ret(lr);
  
    slowcase_entry_pclist[count++] = __ pc();
    __ bind(slow);