add fallback blas_lock implementation

to be used on armv5 and new platforms

common.h

@@ -435,9 +435,23 @@ static inline unsigned long long rpcc(void){
 #define RPCC64BIT
 #endif // !RPCC_DEFINED
 
+#if !defined(BLAS_LOCK_DEFINED) && defined(__GNUC__)
+static void __inline blas_lock(volatile BLASULONG *address){
+
+  do {
+    while (*address) {YIELDING;};
+
+  } while (!__sync_bool_compare_and_swap(address, 0, 1));
+}
+#define BLAS_LOCK_DEFINED
+#endif
+
 #ifndef RPCC_DEFINED
 #error "rpcc() implementation is missing for your platform"
 #endif
+#ifndef BLAS_LOCK_DEFINED
+#error "blas_lock() implementation is missing for your platform"
+#endif
 #endif // !ASSEMBLER
 
 #ifdef OS_LINUX

common_alpha.h

@@ -76,6 +76,7 @@ static void __inline blas_lock(unsigned long *address){
     "30:", address);
 #endif
 }
+#define BLAS_LOCK_DEFINED
 
 static __inline unsigned int rpcc(void){
 

common_arm.h

@@ -51,6 +51,8 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef ASSEMBLER
 
+#if defined(ARMV6) || defined(ARMV7) || defined(ARMV8)
+
 static void __inline blas_lock(volatile BLASULONG *address){
 
   int register ret;
@@ -71,6 +73,8 @@ static void __inline blas_lock(volatile BLASULONG *address){
   MB;
 }
 
+#define BLAS_LOCK_DEFINED
+#endif
 
 static inline int blas_quickdivide(blasint x, blasint y){
   return x / y;

common_arm64.h

@@ -69,6 +69,7 @@ static void __inline blas_lock(volatile BLASULONG *address){
   } while (ret);
 
 }
+#define BLAS_LOCK_DEFINED
 
 
 static inline int blas_quickdivide(blasint x, blasint y){

common_ia64.h

@@ -68,6 +68,7 @@ static __inline void blas_lock(volatile unsigned long *address){
 			  : "ar.ccv", "memory");
   } while (ret);
 }
+#define BLAS_LOCK_DEFINED
 
 static __inline unsigned long rpcc(void) {
   unsigned long clocks;
@@ -100,6 +101,7 @@ static __inline void blas_lock(volatile unsigned long *address){
   while (*address || _InterlockedCompareExchange((volatile int *) address,1,0))
     ;
 }
+#define BLAS_LOCK_DEFINED
 
 static __inline unsigned int rpcc(void) {
   return __getReg(_IA64_REG_AR_ITC);

common_mips64.h

@@ -98,6 +98,7 @@ static void INLINE blas_lock(volatile unsigned long *address){
 
   } while (ret);
 }
+#define BLAS_LOCK_DEFINED
 
 static inline unsigned int rpcc(void){
   unsigned long ret;

common_power.h

@@ -87,6 +87,7 @@ static void INLINE blas_lock(volatile unsigned long *address){
 #endif
   } while (ret);
 }
+#define BLAS_LOCK_DEFINED
 
 static inline unsigned long rpcc(void){
   unsigned long ret;

common_sparc.h

@@ -58,6 +58,7 @@ static void __inline blas_lock(volatile unsigned long *address){
 			 : "memory");
   } while (ret);
 }
+#define BLAS_LOCK_DEFINED
 
 static __inline unsigned long rpcc(void){
   unsigned long clocks;

common_x86.h

@@ -65,6 +65,7 @@ static void __inline blas_lock(volatile BLASULONG *address){
   } while (ret);
 
 }
+#define BLAS_LOCK_DEFINED
 
 static __inline unsigned long long rpcc(void){
   unsigned int a, d;

common_x86_64.h

@@ -74,6 +74,7 @@ static void __inline blas_lock(volatile BLASULONG *address){
 
   } while (ret);
 }
+#define BLAS_LOCK_DEFINED
 
 static __inline BLASULONG rpcc(void){
   BLASULONG a, d;