<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Jul 6, 2016 at 9:33 AM, Etienne Bergeron via llvm-commits <span dir="ltr"><<a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">Author: etienneb<br>
Date: Wed Jul  6 11:33:57 2016<br>
New Revision: 274634<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=274634&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=274634&view=rev</a><br>
Log:<br>
[asan Win64] Implement atomic_compare_exchange_strong for 8 bit<br>
<br>
Patch by: Wei Wang<br>
Differential Revision: <a href="http://reviews.llvm.org/D21950" rel="noreferrer" target="_blank">http://reviews.llvm.org/D21950</a><br>
<br>
<br>
Modified:<br>
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_atomic_msvc.h<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_atomic_msvc.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_atomic_msvc.h?rev=274634&r1=274633&r2=274634&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_atomic_msvc.h?rev=274634&r1=274633&r2=274634&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_atomic_msvc.h (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_atomic_msvc.h Wed Jul  6 11:33:57 2016<br>
@@ -33,6 +33,10 @@ extern "C" long _InterlockedExchange(<br>
 extern "C" long _InterlockedExchangeAdd(  // NOLINT<br>
     long volatile * Addend, long Value);  // NOLINT<br>
 #pragma intrinsic(_InterlockedExchangeAdd)<br>
+extern "C" char _InterlockedCompareExchange8(  // NOLINT<br>
+    char volatile *Destination,                // NOLINT<br>
+    char Exchange, char Comparand);            // NOLINT<br>
+#pragma intrinsic(_InterlockedCompareExchange8)<br>
 extern "C" short _InterlockedCompareExchange16(  // NOLINT<br>
     short volatile *Destination,                 // NOLINT<br>
     short Exchange, short Comparand);            // NOLINT<br>
@@ -175,15 +179,13 @@ INLINE bool atomic_compare_exchange_stro<br>
                                            u8 *cmp,<br>
                                            u8 xchgv,<br>
                                            memory_order mo) {<br>
-#ifdef _WIN64<br>
-  // TODO(wwchrome): Implement same functionality without inline asm.<br>
-  // Inline asm not supported in Win64.<br>
-  __debugbreak();<br>
-  return false;<br>
-#else<br>
   (void)mo;<br>
   DCHECK(!((uptr)a % sizeof(*a)));<br>
   u8 cmpv = *cmp;<br>
+#ifdef _WIN64<br>
+  u8 prev = (u8)_InterlockedCompareExchange8(<br>
+      (volatile char*)&a->val_dont_use, (char)xchgv, (char)cmpv);<br>
+#else<br>
   u8 prev;<br>
   __asm {<br>
     mov al, cmpv<br>
@@ -192,11 +194,11 @@ INLINE bool atomic_compare_exchange_stro<br>
     lock cmpxchg [ecx], dl<br>
     mov prev, al<br>
   }<br></blockquote><div><br></div><div>Could we have used _InterlockedCompareExchange8 on the #else path as well?<br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
+#endif<br>
   if (prev == cmpv)<br>
     return true;<br>
   *cmp = prev;<br>
   return false;<br>
-#endif<br>
 }<br>
<br>
 INLINE bool atomic_compare_exchange_strong(volatile atomic_uintptr_t *a,<br>
<br>
<br>
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</blockquote></div><br></div></div>