Define _ARM_ARCH_6, _ARM_ARCH_5 and _ARM_ARCH_4T, based on

architecture defines passed from the compiler.

Define RET and RETc macros for return and conditional return.  If BX is
available in the current instruction set then make use of it.

Note: these really are from the compiler's -march/-mcpu flags, not
from the kernel config, so they can be relied on in user space.

sys/arch/arm/include/asm.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: asm.h,v 1.5 2003/08/07 16:26:53 agc Exp $	*/
+/*	$NetBSD: asm.h,v 1.6 2004/08/21 10:59:41 rearnsha Exp $	*/
 
 /*
  * Copyright (c) 1990 The Regents of the University of California.
@@ -126,4 +126,35 @@
 	.stabs __STRING(_/**/sym),1,0,0,0
 #endif /* __STDC__ */
 
+#if defined (__ARM_ARCH_6__) || defined (__ARM_ARCH_6J__)
+#define _ARM_ARCH_6
+#endif
+
+#if defined (_ARM_ARCH_6) || defined (__ARM_ARCH_5__) || \
+    defined (__ARM_ARCH_5T__) || defined (__ARM_ARCH_5TE__) || \
+    defined (__ARM_ARCH_5TEJ__)
+#define _ARM_ARCH_5
+#endif
+
+#if defined (_ARM_ARCH_5) || defined (__ARM_ARCH_4T__)
+#define _ARM_ARCH_4T
+#endif
+
+
+#if defined (_ARM_ARCH_4T)
+# define RET	bx	lr
+# ifdef __STDC__
+#  define RETc(c) bx##c	lr
+# else
+#  define RETc(c) bx/**/c	lr
+# endif
+#else
+# define RET	mov	pc, lr
+# ifdef __STDC__
+#  define RETc(c) mov##c	pc, lr
+# else
+#  define RETc(c) mov/**/c	pc, lr
+# endif
+#endif
+
 #endif /* !_ARM_ASM_H_ */