Valerio Pilo CAS for ARMv7 patch.

git-svn-id: http://subversion.jackaudio.org/jack/jack2/trunk/jackmp@4117 0c269be4-1314-0410-8aa9-9f06e86f4224

ChangeLog

@@ -27,12 +27,17 @@ Mario Lang
 Arnold Krille
 Jan Engelhardt
 Adrian Knoth
-David Garcia Garzon
+David Garcia Garzon
+Valerio Pilo
 
 ---------------------------
   Jackdmp changes log
 ---------------------------
 
+2011-02-03 Stephane Letz  <letz@grame.fr>
+
+	* Valerio Pilo CAS for ARMv7 patch.
+
 2011-01-11 Stephane Letz  <letz@grame.fr>
 
 	* Adrian Knoth jack_lsp patch.

linux/JackAtomic_os.h

@@ -69,7 +69,51 @@ static inline char CAS(volatile UInt32 value, UInt32 newvalue, volatile void* ad
 
 #endif
 
-#if !defined(__i386__) && !defined(__x86_64__)  && !defined(__PPC__)
+
+
+#if defined(__thumb__)
+/*
+ * This Compare And Swap code is based off the version found
+ * in MutekH, http://www.mutekh.org/trac/mutekh
+ *
+ * Copyright Alexandre Becoulet <alexandre.becoulet@lip6.fr> (c) 2006
+ */
+
+static inline char CAS(volatile UInt32 value, UInt32 newvalue, volatile void* addr)
+{
+  UInt32 tmp, loaded;
+  UInt32 thumb_tmp;
+
+  asm volatile(
+    ".align 2                                  \n\t"
+    "mov  %[adr], pc                           \n\t"
+    "add  %[adr], %[adr], #4                   \n\t"
+    "bx   %[adr]                               \n\t"
+    "nop                                       \n\t"
+    ".arm                                      \n\t"
+    "1:                                        \n\t"
+    "ldrex   %[loaded], [%[atomic]]            \n\t"
+    "cmp     %[loaded], %[value]               \n\t"
+    "bne     2f                                \n\t"
+    "strex   %[tmp], %[newvalue], [%[atomic]]  \n\t"
+    "tst     %[tmp], #1                        \n\t"
+    "bne     1b                                \n\t"
+    "2:                                        \n\t"
+    "add  %[adr], pc, #1                       \n\t"
+    "bx   %[adr]                               \n\t"
+    : [tmp] "=&r" (tmp), [loaded] "=&r" (loaded), "=m" (*(volatile UInt32*)addr)
+    , [adr] "=&l" (thumb_tmp)
+    : [value] "r" (value), [newvalue] "r" (newvalue), [atomic] "r" (addr)
+    );
+
+  return loaded == value;
+}
+
+#endif
+
+
+
+#if !defined(__i386__) && !defined(__x86_64__)  && !defined(__PPC__) && !defined(__thumb__)
 #warning using builtin gcc (version > 4.1) atomic
 
 static inline char CAS(volatile UInt32 value, UInt32 newvalue, volatile void* addr)