[llvm-commits] [compiler-rt] r154106 - /compiler-rt/trunk/lib/asan/asan_win.cc

[Timur Iskhodzhanov]

Author: timurrrr
Date: Thu Apr  5 12:16:32 2012
New Revision: 154106

URL: http://llvm.org/viewvc/llvm-project?rev=154106&view=rev
Log:
[ASan/Win] Fix build by using inline assembly instead of an unavailable intrinsic function

Modified:
    compiler-rt/trunk/lib/asan/asan_win.cc

Modified: compiler-rt/trunk/lib/asan/asan_win.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_win.cc?rev=154106&r1=154105&r2=154106&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_win.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_win.cc Thu Apr  5 12:16:32 2012
@@ -235,7 +235,16 @@
 }
 
 uint16_t AtomicExchange(uint16_t *a, uint16_t new_val) {
-  return InterlockedExchange16(a, new_val);
+  // InterlockedExchange16 seems unavailable on some MSVS installations.
+  // Everybody stand back, I pretend to know inline assembly!
+  // FIXME: I assume VC is smart enough to save/restore eax/ecx?
+  __asm {
+    mov eax, a
+    mov cx, new_val
+    xchg [eax], cx
+    mov new_val, cx
+  }
+  return new_val;
 }
 
 const char* AsanGetEnv(const char* name) {