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+/*-
+ * Copyright (c) 1983, 1992, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if !defined(lint) && !defined(KERNEL) && defined(LIBC_SCCS)
+static char sccsid[] = "@(#)mcount.c 8.1 (Berkeley) 6/4/93";
+#endif
+
+#include <sys/param.h>
+#include <sys/gmon.h>
+
+/*
+ * mcount is called on entry to each function compiled with the profiling
+ * switch set. _mcount(), which is declared in a machine-dependent way
+ * with _MCOUNT_DECL, does the actual work and is either inlined into a
+ * C routine or called by an assembly stub. In any case, this magic is
+ * taken care of by the MCOUNT definition in <machine/profile.h>.
+ *
+ * _mcount updates data structures that represent traversals of the
+ * program's call graph edges. frompc and selfpc are the return
+ * address and function address that represents the given call graph edge.
+ *
+ * Note: the original BSD code used the same variable (frompcindex) for
+ * both frompcindex and frompc. Any reasonable, modern compiler will
+ * perform this optimization.
+ */
+_MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */
+ register u_long frompc, selfpc;
+{
+ register u_short *frompcindex;
+ register struct tostruct *top, *prevtop;
+ register struct gmonparam *p;
+ register long toindex;
+#ifdef KERNEL
+ register int s;
+#endif
+
+ p = &_gmonparam;
+ /*
+ * check that we are profiling
+ * and that we aren't recursively invoked.
+ */
+ if (p->state != GMON_PROF_ON)
+ return;
+#ifdef KERNEL
+ MCOUNT_ENTER;
+#else
+ p->state = GMON_PROF_BUSY;
+#endif
+ /*
+ * check that frompcindex is a reasonable pc value.
+ * for example: signal catchers get called from the stack,
+ * not from text space. too bad.
+ */
+ frompc -= p->lowpc;
+ if (frompc > p->textsize)
+ goto done;
+
+ frompcindex = &p->froms[frompc / (p->hashfraction * sizeof(*p->froms))];
+ toindex = *frompcindex;
+ if (toindex == 0) {
+ /*
+ * first time traversing this arc
+ */
+ toindex = ++p->tos[0].link;
+ if (toindex >= p->tolimit)
+ /* halt further profiling */
+ goto overflow;
+
+ *frompcindex = toindex;
+ top = &p->tos[toindex];
+ top->selfpc = selfpc;
+ top->count = 1;
+ top->link = 0;
+ goto done;
+ }
+ top = &p->tos[toindex];
+ if (top->selfpc == selfpc) {
+ /*
+ * arc at front of chain; usual case.
+ */
+ top->count++;
+ goto done;
+ }
+ /*
+ * have to go looking down chain for it.
+ * top points to what we are looking at,
+ * prevtop points to previous top.
+ * we know it is not at the head of the chain.
+ */
+ for (; /* goto done */; ) {
+ if (top->link == 0) {
+ /*
+ * top is end of the chain and none of the chain
+ * had top->selfpc == selfpc.
+ * so we allocate a new tostruct
+ * and link it to the head of the chain.
+ */
+ toindex = ++p->tos[0].link;
+ if (toindex >= p->tolimit)
+ goto overflow;
+
+ top = &p->tos[toindex];
+ top->selfpc = selfpc;
+ top->count = 1;
+ top->link = *frompcindex;
+ *frompcindex = toindex;
+ goto done;
+ }
+ /*
+ * otherwise, check the next arc on the chain.
+ */
+ prevtop = top;
+ top = &p->tos[top->link];
+ if (top->selfpc == selfpc) {
+ /*
+ * there it is.
+ * increment its count
+ * move it to the head of the chain.
+ */
+ top->count++;
+ toindex = prevtop->link;
+ prevtop->link = top->link;
+ top->link = *frompcindex;
+ *frompcindex = toindex;
+ goto done;
+ }
+
+ }
+done:
+#ifdef KERNEL
+ MCOUNT_EXIT;
+#else
+ p->state = GMON_PROF_ON;
+#endif
+ return;
+overflow:
+ p->state = GMON_PROF_ERROR;
+#ifdef KERNEL
+ MCOUNT_EXIT;
+#endif
+ return;
+}
+
+/*
+ * Actual definition of mcount function. Defined in <machine/profile.h>,
+ * which is included by <sys/gmon.h>.
+ */
+MCOUNT