code review 5697066: runtime/pprof: support OS X CPU profiling

src/libmach/8db.c

 // Inferno libmach/8db.c
 // http://code.google.com/p/inferno-os/source/browse/utils/libmach/8db.c
 //
-//      Copyright © 1994-1999 Lucent Technologies Inc.
-//      Power PC support Copyright © 1995-2004 C H Forsyth (forsyth@terzarima.net).
-//      Portions Copyright © 1997-1999 Vita Nuova Limited.
-//      Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com).
-//      Revisions Copyright © 2000-2004 Lucent Technologies Inc. and others.
+//      Copyright © 1994-1999 Lucent Technologies Inc.
+//      Power PC support Copyright © 1995-2004 C H Forsyth (forsyth@terzarima.net).
+//      Portions Copyright © 1997-1999 Vita Nuova Limited.
+//      Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com).
+//      Revisions Copyright © 2000-2004 Lucent Technologies Inc. and others.
 //      Portions Copyright © 2009 The Go Authors.  All rights reserved.
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
 // in the Software without restriction, including without limitation the rights
 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 // copies of the Software, and to permit persons to whom the Software is
 // furnished to do so, subject to the following conditions:
 //
 // The above copyright notice and this permission notice shall be included in
@@ skipping 2062 matching lines @@
         }
         if((ip->rex & REXW) == 0)
                 bprint(ip, "%lux", (long)val);
         else
                 bprint(ip, "%llux", val);
 }
 
 static void
 pea(Instr *ip)
 {
+        int base;
+
+        base = ip->base;
+        if(base >= 0 && (ip->rex & REXB))
+                base += 8;
+
         if (ip->mod == 3) {
                 if (ip->osize == 'B')
                         bprint(ip, (ip->rex & REXB? breg64: breg)[(uchar)ip->base]);
-                else if(ip->rex & REXB)
-                        bprint(ip, "%s%s", ANAME(ip), reg[ip->base+8]);
                 else
-                        bprint(ip, "%s%s", ANAME(ip), reg[(uchar)ip->base]);
+                        bprint(ip, "%s%s", ANAME(ip), reg[base]);
                 return;
         }
+
         if (ip->segment)
                 bprint(ip, ip->segment);
-        if (ip->asize == 'E' && ip->base == SP)
+        if (ip->asize == 'E' && base == SP)
                 plocal(ip);
         else {
                 if (ip->base < 0)
                         immediate(ip, ip->disp);
                 else {
                         bprint(ip, "%ux", ip->disp);
                         if(ip->rip)
                                 bprint(ip, "(RIP)");
                         bprint(ip,"(%s%s)", ANAME(ip), reg[ip->rex&REXB? ip->base+8: ip->base]);
                 }
@@ skipping 274 matching lines @@
                 }
                 return 1;
         default:
                 break;
         }
         if (strncmp(op->proto,"JMP", 3) == 0 || strncmp(op->proto,"CALL", 4) == 0)
                 return 1;
         foll[n++] = pc+i.n;
         return n;
 }