Improved profiling for ARM.

sysdeps/arm/machine-gmon.h

@@ -1,5 +1,5 @@
 /* Machine-dependent definitions for profiling support.  ARM version.
-   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -37,19 +37,29 @@ static void mcount_internal (u_long frompc, u_long selfpc);
 #define _MCOUNT_DECL(frompc, selfpc) \
 static void mcount_internal (u_long frompc, u_long selfpc)
 
-#define MCOUNT \
-void _mcount (void)							      \
-{									      \
-  register unsigned long int frompc, selfpc;				      \
-  __asm__("movs fp, fp; "						      \
-          "moveq %0, $0; "						      \
-	  "ldrne %0, [fp, $-4]; "					      \
-	  "ldrne %1, [fp, $-12]; "					      \
-	  "movnes %1, %1; "						      \
-	  "ldrne %1, [%1, $-4]; "					      \
-	  : "=g" (selfpc), "=g" (frompc)				      \
-	  : : "cc"							      \
-	  );								      \
-  if (selfpc)								      \
-    mcount_internal(frompc, selfpc);					      \
+/* This macro/func MUST save r0, r1 because the compiler inserts
+	blind calls to _mount(), ignoring the fact that _mcount may
+	clobber registers; therefore, _mcount may NOT clobber registers */
+/* if (this_fp!=0) {
+	r0 = this_lr
+	r1 = this_fp
+  	r1 = [r1-4] which is caller's fp
+	if (r1!=0) 
+		r1 = caller's lr
+	call mcount_internal(this_lr, caller's_lr)
+   }
+*/  
+#define MCOUNT								\
+void _mcount (void)							\
+{									\
+  __asm__("stmdb	sp!, {r0, r1, r2, r3};"				\
+	  "movs		fp, fp;"				      	\
+	  "moveq	r0, #0;"					\
+	  "ldrne	r0, [fp, $-4];"					\
+	  "ldrne	r1, [fp, $-12];"				\
+	  "movnes	r1, r1;"					\
+	  "ldrne	r1, [r1, $-4];"					\
+	  "movs		r1, r1;"					\
+	  "blne		mcount_internal;"				\
+	  "ldmia	sp!, {r0, r1, r2, r3}");			\
 }