src/cpu/aarch64/vm/aarch64.ad

rev 10243 : 8150394: aarch64: add support for 8.1 LSE CAS instructions
Reviewed-by: aph
Contributed-by: ananth.jasty@caviumnetworks.com, edward.nevill@linaro.org

@@ -4260,38 +4260,42 @@
   %}
 
   enc_class aarch64_enc_cmpxchg(memory mem, iRegLNoSp oldval, iRegLNoSp newval) %{
     MacroAssembler _masm(&cbuf);
     guarantee($mem$$index == -1 && $mem$$disp == 0, "impossible encoding");
-    __ cmpxchg($mem$$base$$Register, $oldval$$Register, $newval$$Register,
-               &Assembler::ldxr, &MacroAssembler::cmp, &Assembler::stlxr);
+    __ cmpxchg(Assembler::xword,
+               $oldval$$Register, $newval$$Register, $mem$$base$$Register,
+               /*acquire*/ false, /*release*/ true);
   %}
 
   enc_class aarch64_enc_cmpxchgw(memory mem, iRegINoSp oldval, iRegINoSp newval) %{
     MacroAssembler _masm(&cbuf);
     guarantee($mem$$index == -1 && $mem$$disp == 0, "impossible encoding");
-    __ cmpxchg($mem$$base$$Register, $oldval$$Register, $newval$$Register,
-               &Assembler::ldxrw, &MacroAssembler::cmpw, &Assembler::stlxrw);
+    __ cmpxchg(Assembler::word,
+               $oldval$$Register, $newval$$Register, $mem$$base$$Register,
+               /*acquire*/ false, /*release*/ true);
   %}
 
 
   // The only difference between aarch64_enc_cmpxchg and
   // aarch64_enc_cmpxchg_acq is that we use load-acquire in the
   // CompareAndSwap sequence to serve as a barrier on acquiring a
   // lock.
   enc_class aarch64_enc_cmpxchg_acq(memory mem, iRegLNoSp oldval, iRegLNoSp newval) %{
     MacroAssembler _masm(&cbuf);
     guarantee($mem$$index == -1 && $mem$$disp == 0, "impossible encoding");
-    __ cmpxchg($mem$$base$$Register, $oldval$$Register, $newval$$Register,
-               &Assembler::ldaxr, &MacroAssembler::cmp, &Assembler::stlxr);
+    __ cmpxchg(Assembler::xword,
+               $oldval$$Register, $newval$$Register, $mem$$base$$Register,
+               /*acquire*/ true, /*release*/ true);
   %}
 
   enc_class aarch64_enc_cmpxchgw_acq(memory mem, iRegINoSp oldval, iRegINoSp newval) %{
     MacroAssembler _masm(&cbuf);
     guarantee($mem$$index == -1 && $mem$$disp == 0, "impossible encoding");
-    __ cmpxchg($mem$$base$$Register, $oldval$$Register, $newval$$Register,
-               &Assembler::ldaxrw, &MacroAssembler::cmpw, &Assembler::stlxrw);
+    __ cmpxchg(Assembler::word,
+               $oldval$$Register, $newval$$Register, $mem$$base$$Register,
+               /*acquire*/ true, /*release*/ true);
   %}
 
 
   // auxiliary used for CompareAndSwapX to set result register
   enc_class aarch64_enc_cset_eq(iRegINoSp res) %{

@@ -4805,11 +4809,16 @@
     // Initialize the box. (Must happen before we update the object mark!)
     __ str(disp_hdr, Address(box, BasicLock::displaced_header_offset_in_bytes()));
 
     // Compare object markOop with mark and if equal exchange scratch1
     // with object markOop.
-    {
+    if (UseLSE) {
+      __ mov(tmp, disp_hdr);
+      __ casal(Assembler::xword, tmp, box, oop);
+      __ cmp(tmp, disp_hdr);
+      __ br(Assembler::EQ, cont);
+    } else {
       Label retry_load;
       __ bind(retry_load);
       __ ldaxr(tmp, oop);
       __ cmp(tmp, disp_hdr);
       __ br(Assembler::NE, cas_failed);

@@ -4855,11 +4864,15 @@
       //
       // Try to CAS m->owner from NULL to current thread.
       __ add(tmp, disp_hdr, (ObjectMonitor::owner_offset_in_bytes()-markOopDesc::monitor_value));
       __ mov(disp_hdr, zr);
 
-      {
+      if (UseLSE) {
+        __ mov(rscratch1, disp_hdr);
+        __ casal(Assembler::xword, rscratch1, rthread, tmp);
+        __ cmp(rscratch1, disp_hdr);
+      } else {
         Label retry_load, fail;
         __ bind(retry_load);
         __ ldaxr(rscratch1, tmp);
         __ cmp(disp_hdr, rscratch1);
         __ br(Assembler::NE, fail);

@@ -4944,11 +4957,15 @@
 
     // Check if it is still a light weight lock, this is is true if we
     // see the stack address of the basicLock in the markOop of the
     // object.
 
-      {
+      if (UseLSE) {
+        __ mov(tmp, box);
+        __ casl(Assembler::xword, tmp, disp_hdr, oop);
+        __ cmp(tmp, box);
+      } else {
         Label retry_load;
         __ bind(retry_load);
         __ ldxr(tmp, oop);
         __ cmp(box, tmp);
         __ br(Assembler::NE, cas_failed);