From dc7ec31f7e1bdcf705bd009c151977b89c19118d Mon Sep 17 00:00:00 2001
From: coleenp <unknown>
Date: Thu, 4 Oct 2012 08:43:14 -0400
Subject: [PATCH] 6884973: java -XX:Atomics=2 crashes Summary: Remove buggy
 experimental option Reviewed-by: acorn, coleenp Contributed-by:
 harold.seigel@oracle.com

---
 src/cpu/x86/vm/assembler_x86.cpp | 32 ++++++--------------------------
 src/share/vm/runtime/globals.hpp |  3 ---
 2 files changed, 6 insertions(+), 29 deletions(-)

diff --git a/src/cpu/x86/vm/assembler_x86.cpp b/src/cpu/x86/vm/assembler_x86.cpp
index 66798405e..734d739a6 100644
--- a/src/cpu/x86/vm/assembler_x86.cpp
+++ b/src/cpu/x86/vm/assembler_x86.cpp
@@ -1170,26 +1170,11 @@ void Assembler::cmpw(Address dst, int imm16) {
 // and stores reg into adr if so; otherwise, the value at adr is loaded into rax,.
 // The ZF is set if the compared values were equal, and cleared otherwise.
 void Assembler::cmpxchgl(Register reg, Address adr) { // cmpxchg
-  if (Atomics & 2) {
-     // caveat: no instructionmark, so this isn't relocatable.
-     // Emit a synthetic, non-atomic, CAS equivalent.
-     // Beware.  The synthetic form sets all ICCs, not just ZF.
-     // cmpxchg r,[m] is equivalent to rax, = CAS (m, rax, r)
-     cmpl(rax, adr);
-     movl(rax, adr);
-     if (reg != rax) {
-        Label L ;
-        jcc(Assembler::notEqual, L);
-        movl(adr, reg);
-        bind(L);
-     }
-  } else {
-     InstructionMark im(this);
-     prefix(adr, reg);
-     emit_byte(0x0F);
-     emit_byte(0xB1);
-     emit_operand(reg, adr);
-  }
+  InstructionMark im(this);
+  prefix(adr, reg);
+  emit_byte(0x0F);
+  emit_byte(0xB1);
+  emit_operand(reg, adr);
 }
 
 void Assembler::comisd(XMMRegister dst, Address src) {
@@ -1513,12 +1498,7 @@ void Assembler::leal(Register dst, Address src) {
 }
 
 void Assembler::lock() {
-  if (Atomics & 1) {
-     // Emit either nothing, a NOP, or a NOP: prefix
-     emit_byte(0x90) ;
-  } else {
-     emit_byte(0xF0);
-  }
+  emit_byte(0xF0);
 }
 
 void Assembler::lzcntl(Register dst, Register src) {
diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
index 8ecd8d304..7ac7c4563 100644
--- a/src/share/vm/runtime/globals.hpp
+++ b/src/share/vm/runtime/globals.hpp
@@ -1066,9 +1066,6 @@ class CommandLineFlags {
                                                                             \
   product(bool, MonitorInUseLists, false, "Track Monitors for Deflation")   \
                                                                             \
-  product(intx, Atomics, 0,                                                 \
-          "(Unsafe,Unstable) Diagnostic - Controls emission of atomics")    \
-                                                                            \
   product(intx, SyncFlags, 0, "(Unsafe,Unstable) Experimental Sync flags" ) \
                                                                             \
   product(intx, SyncVerbose, 0, "(Unstable)" )                              \
-- 
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