[arm64] Use exclusive instructions in exchange

test/cctest/test-disasm-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1242 matching lines @@
   COMPARE(ldpsw(x0, x1, MemOperand(x2)), "ldpsw x0, x1, [x2]");
   COMPARE(ldpsw(x3, x4, MemOperand(x5, 16)), "ldpsw x3, x4, [x5, #16]");
   COMPARE(ldpsw(x6, x7, MemOperand(x8, -32, PreIndex)),
           "ldpsw x6, x7, [x8, #-32]!");
   COMPARE(ldpsw(x9, x10, MemOperand(x11, 128, PostIndex)),
           "ldpsw x9, x10, [x11], #128");
 
   CLEANUP();
 }
 
+TEST_(load_store_exclusive) {
+  SET_UP_MASM();
+
+  COMPARE(ldxr(w6, x7), "ldxr w6, [x7]");
+  COMPARE(ldxrb(w8, x9), "ldxrb w8, [x9]");
+  COMPARE(ldxrh(w10, x11), "ldxrh w10, [x11]");
+  COMPARE(stxr(w18, w19, x20), "stxr w18, w19, [x20]");
+  COMPARE(stxrb(w21, w22, x23), "stxrb w21, w22, [x23]");
+  COMPARE(stxrh(w24, w25, x26), "stxrh w24, w25, [x26]");
+  COMPARE(ldxr(wzr, csp), "ldxr wzr, [csp]");
+  COMPARE(stxr(wzr, wzr, csp), "stxr wzr, wzr, [csp]");
+
+  CLEANUP();
+}
+
 TEST_(load_store_acquire_release) {
   SET_UP_MASM();
 
   COMPARE(ldar(w0, x1), "ldar w0, [x1]");
   COMPARE(ldarb(w2, x3), "ldarb w2, [x3]");
   COMPARE(ldarh(w4, x5), "ldarh w4, [x5]");
   COMPARE(ldaxr(w6, x7), "ldaxr w6, [x7]");
   COMPARE(ldaxrb(w8, x9), "ldaxrb w8, [x9]");
   COMPARE(ldaxrh(w10, x11), "ldaxrh w10, [x11]");
   COMPARE(stlr(w12, x13), "stlr w12, [x13]");
   COMPARE(stlrb(w14, x15), "stlrb w14, [x15]");
   COMPARE(stlrh(w16, x17), "stlrh w16, [x17]");
   COMPARE(stlxr(w18, w19, x20), "stlxr w18, w19, [x20]");
   COMPARE(stlxrb(w21, w22, x23), "stlxrb w21, w22, [x23]");
   COMPARE(stlxrh(w24, w25, x26), "stlxrh w24, w25, [x26]");
+  COMPARE(ldar(wzr, csp), "ldar wzr, [csp]");
+  COMPARE(stlr(wzr, csp), "stlr wzr, [csp]");
+  COMPARE(ldaxr(wzr, csp), "ldaxr wzr, [csp]");
+  COMPARE(stlxr(wzr, wzr, csp), "stlxr wzr, wzr, [csp]");
 
   CLEANUP();
 }
 
 #if 0  // TODO(all): enable.
 TEST_(load_literal) {
   SET_UP_ASM();
 
   COMPARE_PREFIX(ldr(x10, 0x1234567890abcdefUL),  "ldr x10, pc+8");
   COMPARE_PREFIX(ldr(w20, 0xfedcba09),  "ldr w20, pc+8");
@@ skipping 483 matching lines @@
   COMPARE(Dsb(FullSystem, BarrierOther), "dsb sy (0b1100)");
   COMPARE(Dsb(InnerShareable, BarrierOther), "dsb sy (0b1000)");
   COMPARE(Dsb(NonShareable, BarrierOther), "dsb sy (0b0100)");
   COMPARE(Dsb(OuterShareable, BarrierOther), "dsb sy (0b0000)");
 
   // ISB
   COMPARE(Isb(), "isb");
 
   CLEANUP();
 }