|
0
|
1 /* This file contains the list of the debug counter for GCC.
|
|
|
2 Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
|
|
|
3
|
|
|
4 This file is part of GCC.
|
|
|
5
|
|
|
6 GCC is free software; you can redistribute it and/or modify it under
|
|
|
7 the terms of the GNU General Public License as published by the Free
|
|
|
8 Software Foundation; either version 3, or (at your option) any later
|
|
|
9 version.
|
|
|
10
|
|
|
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
|
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
|
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
|
14 for more details.
|
|
|
15
|
|
|
16 You should have received a copy of the GNU General Public License
|
|
|
17 along with GCC; see the file COPYING3. If not see
|
|
|
18 <http://www.gnu.org/licenses/>. */
|
|
|
19
|
|
|
20
|
|
|
21 /* A debug counter provides you a way to count an event
|
|
|
22 and return false after the counter has exceeded the threshold
|
|
|
23 specified by the option.
|
|
|
24
|
|
|
25 What is it used for ?
|
|
|
26
|
|
|
27 This is primarily used to speed up the search for the bad transformation
|
|
|
28 an optimization pass does. By doing a binary search on N,
|
|
|
29 you can quickly narrow down to one transformation
|
|
|
30 which is bad, or which triggers the bad behavior downstream
|
|
|
31 (usually in the form of the badly generated code).
|
|
|
32
|
|
|
33 How does it work ?
|
|
|
34
|
|
|
35 Every time dbg_cnt(named-counter) is called,
|
|
|
36 the counter is incremented for the named-counter.
|
|
|
37 And the incremented value is compared against the threshold (limit)
|
|
|
38 specified by the option.
|
|
|
39 dbg_cnt () returns true if it is at or below threshold, and false if above.
|
|
|
40
|
|
|
41 How to add a new one ?
|
|
|
42
|
|
|
43 To add a new counter, simply add an entry below with some descriptive name,
|
|
|
44 and add call(s) to dbg_cnt(your-counter-name) in appropriate places.
|
|
|
45 Usually, you want to control at the finest granularity
|
|
|
46 any particular transformation can happen.
|
|
|
47 e.g. for each instruction in a dead code elimination,
|
|
|
48 or for each copy instruction in register coalescing,
|
|
|
49 or constant-propagation for each insn,
|
|
|
50 or a block straightening, etc.
|
|
|
51 See dce.c for an example. With the dbg_cnt () call in dce.c,
|
|
|
52 now a developer can use -fdbg-cnt=dce:N
|
|
|
53 to stop doing the dead code elimination after N times.
|
|
|
54
|
|
|
55 How to use it ?
|
|
|
56
|
|
|
57 By default, all limits are UINT_MAX.
|
|
|
58 Since debug count is unsigned int, <= UINT_MAX returns true always.
|
|
|
59 i.e. dbg_cnt() returns true always regardless of the counter value
|
|
|
60 (although it still counts the event).
|
|
|
61 Use -fdbg-cnt=counter1:N,counter2:M,...
|
|
|
62 which sets the limit for counter1 to N, and the limit for counter2 to M, etc.
|
|
|
63 e.g. setting a limit to zero will make dbg_cnt () return false *always*.
|
|
|
64
|
|
|
65 The following shell file can then be used to binary search for
|
|
|
66 exact transformation that causes the bug. A second shell script
|
|
|
67 should be written, say "tryTest", which exits with 1 if the
|
|
|
68 compiled program fails and exits with 0 if the program succeeds.
|
|
|
69 This shell script should take 1 parameter, the value to be passed
|
|
|
70 to set the counter of the compilation command in tryTest. Then,
|
|
|
71 assuming that the following script is called binarySearch,
|
|
|
72 the command:
|
|
|
73
|
|
|
74 binarySearch tryTest
|
|
|
75
|
|
|
76 will automatically find the highest value of the counter for which
|
|
|
77 the program fails. If tryTest never fails, binarySearch will
|
|
|
78 produce unpredictable results as it will try to find an upper bound
|
|
|
79 that does not exist.
|
|
|
80
|
|
|
81 When dbgcnt does hits the limit, it writes a comment in the current
|
|
|
82 dump_file of the form:
|
|
|
83
|
|
|
84 ***dbgcnt: limit reached for %s.***
|
|
|
85
|
|
|
86 Assuming that the dump file is logging the analysis/transformations
|
|
|
87 it is making, this pinpoints the exact position in the log file
|
|
|
88 where the problem transformation is being logged.
|
|
|
89
|
|
|
90 =====================================
|
|
|
91 #!/bin/bash
|
|
|
92
|
|
|
93 while getopts "l:u:i:" opt
|
|
|
94 do
|
|
|
95 case $opt in
|
|
|
96 l) lb="$OPTARG";;
|
|
|
97 u) ub="$OPTARG";;
|
|
|
98 i) init="$OPTARG";;
|
|
|
99 ?) usage; exit 3;;
|
|
|
100 esac
|
|
|
101 done
|
|
|
102
|
|
|
103 shift $(($OPTIND - 1))
|
|
|
104 echo $@
|
|
|
105 cmd=${1+"${@}"}
|
|
|
106
|
|
|
107 lb=${lb:=0}
|
|
|
108 init=${init:=100}
|
|
|
109
|
|
|
110 $cmd $lb
|
|
|
111 lb_val=$?
|
|
|
112 if [ -z "$ub" ]; then
|
|
|
113 # find the upper bound
|
|
|
114 ub=$(($init + $lb))
|
|
|
115 true
|
|
|
116 while [ $? -eq $lb_val ]; do
|
|
|
117 ub=$(($ub * 10))
|
|
|
118 #ub=`expr $ub \* 10`
|
|
|
119 $cmd $ub
|
|
|
120 done
|
|
|
121 fi
|
|
|
122
|
|
|
123 echo command: $cmd
|
|
|
124
|
|
|
125 true
|
|
|
126 while [ `expr $ub - $lb` -gt 1 ]; do
|
|
|
127 try=$(($lb + ( $ub - $lb ) / 2))
|
|
|
128 $cmd $try
|
|
|
129 if [ $? -eq $lb_val ]; then
|
|
|
130 lb=$try
|
|
|
131 else
|
|
|
132 ub=$try
|
|
|
133 fi
|
|
|
134 done
|
|
|
135
|
|
|
136 echo lbound: $lb
|
|
|
137 echo ubound: $ub
|
|
|
138
|
|
|
139 =====================================
|
|
|
140
|
|
|
141 */
|
|
|
142
|
|
|
143 /* Debug counter definitions. */
|
|
|
144 DEBUG_COUNTER (auto_inc_dec)
|
|
|
145 DEBUG_COUNTER (cfg_cleanup)
|
|
|
146 DEBUG_COUNTER (cse2_move2add)
|
|
|
147 DEBUG_COUNTER (cprop1)
|
|
|
148 DEBUG_COUNTER (cprop2)
|
|
|
149 DEBUG_COUNTER (dce)
|
|
|
150 DEBUG_COUNTER (dce_fast)
|
|
|
151 DEBUG_COUNTER (dce_ud)
|
|
|
152 DEBUG_COUNTER (delete_trivial_dead)
|
|
|
153 DEBUG_COUNTER (df_byte_scan)
|
|
|
154 DEBUG_COUNTER (dse)
|
|
|
155 DEBUG_COUNTER (dse1)
|
|
|
156 DEBUG_COUNTER (dse2)
|
|
|
157 DEBUG_COUNTER (gcse)
|
|
|
158 DEBUG_COUNTER (gcse2_delete)
|
|
|
159 DEBUG_COUNTER (global_alloc_at_func)
|
|
|
160 DEBUG_COUNTER (global_alloc_at_reg)
|
|
|
161 DEBUG_COUNTER (ia64_sched2)
|
|
|
162 DEBUG_COUNTER (if_conversion)
|
|
|
163 DEBUG_COUNTER (if_after_combine)
|
|
|
164 DEBUG_COUNTER (if_after_reload)
|
|
|
165 DEBUG_COUNTER (jump_bypass)
|
|
|
166 DEBUG_COUNTER (local_alloc_for_sched)
|
|
|
167 DEBUG_COUNTER (postreload_cse)
|
|
|
168 DEBUG_COUNTER (pre_insn)
|
|
|
169 DEBUG_COUNTER (treepre_insert)
|
|
|
170 DEBUG_COUNTER (sched2_func)
|
|
|
171 DEBUG_COUNTER (sched_block)
|
|
|
172 DEBUG_COUNTER (sched_func)
|
|
|
173 DEBUG_COUNTER (sched_insn)
|
|
|
174 DEBUG_COUNTER (sched_region)
|
|
|
175 DEBUG_COUNTER (sel_sched_cnt)
|
|
|
176 DEBUG_COUNTER (sel_sched_region_cnt)
|
|
|
177 DEBUG_COUNTER (sel_sched_insn_cnt)
|
|
|
178 DEBUG_COUNTER (sms_sched_loop)
|
|
|
179 DEBUG_COUNTER (split_for_sched2)
|
|
|
180 DEBUG_COUNTER (tail_call)
|
