jdk8-mips64-public/hotspot: changeset 2355:ec8c74742417

7005241: C1: SEGV in java.util.concurrent.LinkedTransferQueue.xfer() with compressed oops
Summary: Implementation of the CAS primitive for x64 compressed oops was incorrect. It kills rscratch2 register (r11), which is allocatable in C1. Also, we don't need to restore cmpval as it's never used after that, so we need only one temporary register, which can be scratch1.
Reviewed-by: kvn, never

     1.1 --- a/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	Tue Dec 07 11:00:02 2010 -0800
     1.2 +++ b/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	Wed Dec 08 02:36:36 2010 -0800
     1.3 @@ -1993,15 +1993,14 @@
     1.4      if ( op->code() == lir_cas_obj) {
     1.5  #ifdef _LP64
     1.6        if (UseCompressedOops) {
     1.7 -        __ mov(rscratch1, cmpval);
     1.8          __ encode_heap_oop(cmpval);
     1.9 -        __ mov(rscratch2, newval);
    1.10 -        __ encode_heap_oop(rscratch2);
    1.11 +        __ mov(rscratch1, newval);
    1.12 +        __ encode_heap_oop(rscratch1);
    1.13          if (os::is_MP()) {
    1.14            __ lock();
    1.15          }
    1.16 -        __ cmpxchgl(rscratch2, Address(addr, 0));
    1.17 -        __ mov(cmpval, rscratch1);
    1.18 +        // cmpval (rax) is implicitly used by this instruction
    1.19 +        __ cmpxchgl(rscratch1, Address(addr, 0));
    1.20        } else
    1.21  #endif
    1.22        {

Mercurial > jdk8-mips64-public > hotspot / changeset

changeset

7005241: C1: SEGV in java.util.concurrent.LinkedTransferQueue.xfer() with compressed oops