1/* This file contains the list of the debug counter for GCC.
2 Copyright (C) 2006-2017 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along 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
93while getopts "l:u:i:" opt
94do
95 case $opt in
96 l) lb="$OPTARG";;
97 u) ub="$OPTARG";;
98 i) init="$OPTARG";;
99 ?) usage; exit 3;;
100 esac
101done
102
103shift $(($OPTIND - 1))
104echo $@
105cmd=${1+"${@}"}
106
107lb=${lb:=0}
108init=${init:=100}
109
110$cmd $lb
111lb_val=$?
112if [ -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
121fi
122
123echo command: $cmd
124
125true
126while [ `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
134done
135
136echo lbound: $lb
137echo ubound: $ub
138
139=====================================
140
141*/
142
143/* Debug counter definitions. */
144DEBUG_COUNTER (asan_use_after_scope)
145DEBUG_COUNTER (auto_inc_dec)
146DEBUG_COUNTER (ccp)
147DEBUG_COUNTER (cfg_cleanup)
148DEBUG_COUNTER (cprop)
149DEBUG_COUNTER (cse2_move2add)
150DEBUG_COUNTER (dce)
151DEBUG_COUNTER (dce_fast)
152DEBUG_COUNTER (dce_ud)
153DEBUG_COUNTER (delete_trivial_dead)
154DEBUG_COUNTER (devirt)
155DEBUG_COUNTER (df_byte_scan)
156DEBUG_COUNTER (dse)
157DEBUG_COUNTER (dse1)
158DEBUG_COUNTER (dse2)
159DEBUG_COUNTER (eipa_sra)
160DEBUG_COUNTER (gcse2_delete)
161DEBUG_COUNTER (global_alloc_at_func)
162DEBUG_COUNTER (global_alloc_at_reg)
163DEBUG_COUNTER (graphite_scop)
164DEBUG_COUNTER (hoist)
165DEBUG_COUNTER (hoist_insn)
166DEBUG_COUNTER (ia64_sched2)
167DEBUG_COUNTER (if_after_combine)
168DEBUG_COUNTER (if_after_reload)
169DEBUG_COUNTER (if_conversion)
170DEBUG_COUNTER (if_conversion_tree)
171DEBUG_COUNTER (ira_move)
172DEBUG_COUNTER (local_alloc_for_sched)
173DEBUG_COUNTER (merged_ipa_icf)
174DEBUG_COUNTER (postreload_cse)
175DEBUG_COUNTER (pre)
176DEBUG_COUNTER (pre_insn)
177DEBUG_COUNTER (prefetch)
178DEBUG_COUNTER (registered_jump_thread)
179DEBUG_COUNTER (sched2_func)
180DEBUG_COUNTER (sched_block)
181DEBUG_COUNTER (sched_breakdep)
182DEBUG_COUNTER (sched_func)
183DEBUG_COUNTER (sched_insn)
184DEBUG_COUNTER (sched_region)
185DEBUG_COUNTER (sel_sched_cnt)
186DEBUG_COUNTER (sel_sched_insn_cnt)
187DEBUG_COUNTER (sel_sched_region_cnt)
188DEBUG_COUNTER (sms_sched_loop)
189DEBUG_COUNTER (split_for_sched2)
190DEBUG_COUNTER (store_motion)
191DEBUG_COUNTER (stv_conversion)
192DEBUG_COUNTER (tail_call)
193DEBUG_COUNTER (treepre_insert)
194DEBUG_COUNTER (tree_sra)
195DEBUG_COUNTER (vect_loop)
196DEBUG_COUNTER (vect_slp)
197DEBUG_COUNTER (dom_unreachable_edges)
198