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glibc  2.9
machine-gmon.h
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00001 /* Machine-dependent definitions for profiling support.  ARM version.
00002    Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 /* GCC for the ARM cannot compile __builtin_return_address(N) for N != 0, 
00021    so we must use an assembly stub.  */
00022 
00023 #include <sysdep.h>
00024 #ifndef NO_UNDERSCORES
00025 /* The asm symbols for C functions are `_function'.
00026    The canonical name for the counter function is `mcount', no _.  */
00027 void _mcount (void) asm ("mcount");
00028 #else
00029 /* The canonical name for the function is `_mcount' in both C and asm,
00030    but some old asm code might assume it's `mcount'.  */
00031 void _mcount (void);
00032 weak_alias (_mcount, mcount)
00033 #endif
00034 
00035 static void mcount_internal (u_long frompc, u_long selfpc) __attribute_used__;
00036 
00037 #define _MCOUNT_DECL(frompc, selfpc) \
00038 static void mcount_internal (u_long frompc, u_long selfpc)
00039 
00040 /* This macro/func MUST save r0, r1 because the compiler inserts
00041        blind calls to _mount(), ignoring the fact that _mcount may
00042        clobber registers; therefore, _mcount may NOT clobber registers */
00043 /* if (this_fp!=0) {
00044        r0 = this_fp
00045        r1 = this_lr
00046        r1 = [r1-4] which is caller's lr 
00047        if (r1!=0) 
00048               r1 = caller's lr
00049        call mcount_internal(this_lr, caller's_lr)
00050    }
00051 */
00052 
00053 #define MCOUNT                                                        \
00054 void _mcount (void)                                            \
00055 {                                                              \
00056   __asm__("stmdb     sp!, {r0, r1, r2, r3};"                          \
00057          "movs              fp, fp;"                                  \
00058           "moveq     r1, #0;"                                  \
00059          "ldrne      r1, [fp, $-4];"                                  \
00060          "ldrne      r0, [fp, $-12];"                          \
00061          "movnes     r0, r0;"                                  \
00062          "ldrne      r0, [r0, $-4];"                                  \
00063          "movs              r0, r0;"                                  \
00064          "blne              mcount_internal;"                         \
00065          "ldmia      sp!, {r0, r1, r2, r3}");                  \
00066 }
00067