src/hotspot/cpu/arm/macroAssembler_arm.cpp

rev 54101 : 8214512: ARM32: Jtreg test compiler/c2/Test8062950.java fails on ARM
Reviewed-by: dlong, enevill, bulasevich
Contributed-by: nick.gasson@arm.com, christoph.goettschkes@microdoc.com

*** 2994,3004 ****
  #endif // ASSERT
  
  #endif // AARCH64
  
  #ifdef COMPILER2
! void MacroAssembler::fast_lock(Register Roop, Register Rbox, Register Rscratch, Register Rscratch2 AARCH64_ONLY_ARG(Register Rscratch3))
  {
    assert(VM_Version::supports_ldrex(), "unsupported, yet?");
  
    Register Rmark      = Rscratch2;
  
--- 2994,3004 ----
  #endif // ASSERT
  
  #endif // AARCH64
  
  #ifdef COMPILER2
! void MacroAssembler::fast_lock(Register Roop, Register Rbox, Register Rscratch, Register Rscratch2, Register scratch3)
  {
    assert(VM_Version::supports_ldrex(), "unsupported, yet?");
  
    Register Rmark      = Rscratch2;
  
*** 3008,3026 ****
    assert(Rbox != Rmark, "");
  
    Label fast_lock, done;
  
    if (UseBiasedLocking && !UseOptoBiasInlining) {
!     Label failed;
! #ifdef AARCH64
!     biased_locking_enter(Roop, Rmark, Rscratch, false, Rscratch3, done, failed);
! #else
!     biased_locking_enter(Roop, Rmark, Rscratch, false, noreg, done, failed);
! #endif
!     bind(failed);
    }
  
    ldr(Rmark, Address(Roop, oopDesc::mark_offset_in_bytes()));
    tst(Rmark, markOopDesc::unlocked_value);
    b(fast_lock, ne);
  
    // Check for recursive lock
--- 3008,3024 ----
    assert(Rbox != Rmark, "");
  
    Label fast_lock, done;
  
    if (UseBiasedLocking && !UseOptoBiasInlining) {
!     assert(scratch3 != noreg, "need extra temporary for -XX:-UseOptoBiasInlining");
!     biased_locking_enter(Roop, Rmark, Rscratch, false, scratch3, done, done);
!     // Fall through if lock not biased otherwise branch to done
    }
  
+   // Invariant: Rmark loaded below does not contain biased lock pattern
+ 
    ldr(Rmark, Address(Roop, oopDesc::mark_offset_in_bytes()));
    tst(Rmark, markOopDesc::unlocked_value);
    b(fast_lock, ne);
  
    // Check for recursive lock
*** 3055,3064 ****
--- 3053,3065 ----
    bool one_shot = true;
    cas_for_lock_acquire(Rmark, Rbox, Roop, Rscratch, done, allow_fallthrough_on_failure, one_shot);
  
    bind(done);
  
+   // At this point flags are set as follows:
+   //  EQ -> Success
+   //  NE -> Failure, branch to slow path
  }
  
  void MacroAssembler::fast_unlock(Register Roop, Register Rbox, Register Rscratch, Register Rscratch2  AARCH64_ONLY_ARG(Register Rscratch3))
  {
    assert(VM_Version::supports_ldrex(), "unsupported, yet?");