From 8109a9af1ffcfd8c2e128862a9c20324221fdd8b Mon Sep 17 00:00:00 2001
From: Bruce Evans <bde@FreeBSD.org>
Date: Wed, 6 Mar 2002 09:47:36 +0000
Subject: [PATCH] Fixed some misspellings of 2 as sizeof(UNIT) so that they
 won't break things when sizeof(UNIT) becomes a runtime parameter.  The
 relevant 2 is the one in profil(2)'s scaling of pc's to bucket numbers:

	   bucket = (pc - offset) / 2 * profil_scale / 65536

gprof(1) must duplicate this scaling, bug for bug compatibly, so it
must first do an integer division by 2 although this mainly makes
scales larger than 65536 useless.  sizeof(UNIT) was already wrong in
gprof4, but there were no problems because the fake profil scale is a
multiple of 2.

There are also some rounding bugs in the scaling, but these are only
problems if profil(2) is used directly to create unusual (and not
useful) scales.
---
 usr.bin/gprof/gprof.c      | 20 ++++++++++----------
 usr.bin/gprof/gprof.h      |  8 +++++++-
 usr.bin/gprof/printgprof.c |  4 ++--
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/usr.bin/gprof/gprof.c b/usr.bin/gprof/gprof.c
index 1d43fe6998e9..8d529cb3c601 100644
--- a/usr.bin/gprof/gprof.c
+++ b/usr.bin/gprof/gprof.c
@@ -48,8 +48,6 @@ static const char rcsid[] =
 #include <err.h>
 #include "gprof.h"
 
-#define	UNITS_TO_CODE	(OFFSET_OF_CODE / sizeof(UNIT))
-
 static int valcmp(const void *, const void *);
 
 
@@ -306,8 +304,8 @@ openpfile(filename)
     }
     s_lowpc = (unsigned long) gmonhdr.lpc;
     s_highpc = (unsigned long) gmonhdr.hpc;
-    lowpc = (unsigned long)gmonhdr.lpc / sizeof(UNIT);
-    highpc = (unsigned long)gmonhdr.hpc / sizeof(UNIT);
+    lowpc = (unsigned long)gmonhdr.lpc / HISTORICAL_SCALE_2;
+    highpc = (unsigned long)gmonhdr.hpc / HISTORICAL_SCALE_2;
     sampbytes = gmonhdr.ncnt - size;
     nsamples = sampbytes / sizeof (UNIT);
 #   ifdef DEBUG
@@ -525,8 +523,8 @@ asgnsamples()
 #		ifdef DEBUG
 		    if (debug & SAMPLEDEBUG) {
 			printf("[asgnsamples] (0x%lx->0x%lx-0x%lx) %s gets %f ticks %lu overlap\n",
-				nl[j].value/sizeof(UNIT), svalue0, svalue1,
-				nl[j].name,
+				nl[j].value / HISTORICAL_SCALE_2,
+				svalue0, svalue1, nl[j].name,
 				overlap * time / scale, overlap);
 		    }
 #		endif DEBUG
@@ -573,17 +571,19 @@ alignentries()
     unsigned long	bucket_of_code;
 
     for (nlp = nl; nlp < npe; nlp++) {
-	nlp -> svalue = nlp -> value / sizeof(UNIT);
+	nlp -> svalue = nlp -> value / HISTORICAL_SCALE_2;
 	bucket_of_entry = (nlp->svalue - lowpc) / scale;
-	bucket_of_code = (nlp->svalue + UNITS_TO_CODE - lowpc) / scale;
+	bucket_of_code = (nlp->svalue + OFFSET_OF_CODE / HISTORICAL_SCALE_2 -
+	  lowpc) / scale;
 	if (bucket_of_entry < bucket_of_code) {
 #	    ifdef DEBUG
 		if (debug & SAMPLEDEBUG) {
 		    printf("[alignentries] pushing svalue 0x%lx to 0x%lx\n",
-			    nlp->svalue, nlp->svalue + UNITS_TO_CODE);
+			    nlp->svalue,
+			    nlp->svalue + OFFSET_OF_CODE / HISTORICAL_SCALE_2);
 		}
 #	    endif DEBUG
-	    nlp->svalue += UNITS_TO_CODE;
+	    nlp->svalue += OFFSET_OF_CODE / HISTORICAL_SCALE_2;
 	}
     }
 }
diff --git a/usr.bin/gprof/gprof.h b/usr.bin/gprof/gprof.h
index 4d2b949402df..c37c00eee4b1 100644
--- a/usr.bin/gprof/gprof.h
+++ b/usr.bin/gprof/gprof.h
@@ -77,6 +77,13 @@ typedef int	bool;
 #define	FALSE	0
 #define	TRUE	1
 
+    /*
+     *	Historical scale factor in profil(2)'s algorithm for converting
+     *	pc addresses to bucket numbers.  This now just complicates the
+     *	scaling and makes bucket:pc densities of more than 1/2 useless.
+     */
+#define	HISTORICAL_SCALE_2	2
+
     /*
      *	ticks per second
      */
@@ -87,7 +94,6 @@ typedef	int64_t UNIT;
 #else
 typedef	u_short UNIT;		/* unit of profiling */
 #endif
-#define	UNITS_TO_CODE	(OFFSET_OF_CODE / sizeof(UNIT))
 
 char	*a_outname;
 #define	A_OUTNAME		"a.out"
diff --git a/usr.bin/gprof/printgprof.c b/usr.bin/gprof/printgprof.c
index 945ff8d36bea..80698cfd65ad 100644
--- a/usr.bin/gprof/printgprof.c
+++ b/usr.bin/gprof/printgprof.c
@@ -100,7 +100,7 @@ flatprofheader()
 	printblurb( _PATH_FLAT_BLURB );
     }
     printf( "\ngranularity: each sample hit covers %g byte(s)" ,
-	    scale * sizeof(UNIT) );
+	    scale * HISTORICAL_SCALE_2 );
     if ( totime > 0.0 ) {
 	printf( " for %.2f%% of %.2f seconds\n\n" ,
 		100.0/totime , totime / hz );
@@ -161,7 +161,7 @@ gprofheader()
 	printblurb( _PATH_CALLG_BLURB );
     }
     printf( "\ngranularity: each sample hit covers %g byte(s)" ,
-	    scale * sizeof(UNIT) );
+	    scale * HISTORICAL_SCALE_2 );
     if ( printtime > 0.0 ) {
 	printf( " for %.2f%% of %.2f seconds\n\n" ,
 		100.0/printtime , printtime / hz );