Mercurial > hg > CbC > CbC_gcc
annotate gcc/stack-ptr-mod.c @ 116:367f9f4f266e
fix gimple.h
author | mir3636 |
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date | Tue, 28 Nov 2017 20:22:01 +0900 |
parents | 04ced10e8804 |
children | 84e7813d76e9 |
rev | line source |
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55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
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1 /* Discover if the stack pointer is modified in a function. |
111 | 2 Copyright (C) 2007-2017 Free Software Foundation, Inc. |
0 | 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 #include "config.h" | |
21 #include "system.h" | |
22 #include "coretypes.h" | |
111 | 23 #include "backend.h" |
0 | 24 #include "rtl.h" |
111 | 25 #include "df.h" |
26 #include "memmodel.h" | |
27 #include "emit-rtl.h" | |
0 | 28 #include "tree-pass.h" |
29 | |
30 /* Determine if the stack pointer is constant over the life of the function. | |
31 Only useful before prologues have been emitted. */ | |
32 | |
33 static void | |
34 notice_stack_pointer_modification_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, | |
35 void *data ATTRIBUTE_UNUSED) | |
36 { | |
37 if (x == stack_pointer_rtx | |
38 /* The stack pointer is only modified indirectly as the result | |
39 of a push until later. See the comments in rtl.texi | |
40 regarding Embedded Side-Effects on Addresses. */ | |
41 || (MEM_P (x) | |
42 && GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == RTX_AUTOINC | |
43 && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) | |
111 | 44 crtl->sp_is_unchanging = 0; |
0 | 45 } |
46 | |
111 | 47 /* Some targets can emit simpler epilogues if they know that sp was |
48 not ever modified during the function. After reload, of course, | |
49 we've already emitted the epilogue so there's no sense searching. */ | |
50 | |
51 namespace { | |
52 | |
53 const pass_data pass_data_stack_ptr_mod = | |
54 { | |
55 RTL_PASS, /* type */ | |
56 "*stack_ptr_mod", /* name */ | |
57 OPTGROUP_NONE, /* optinfo_flags */ | |
58 TV_NONE, /* tv_id */ | |
59 0, /* properties_required */ | |
60 0, /* properties_provided */ | |
61 0, /* properties_destroyed */ | |
62 0, /* todo_flags_start */ | |
63 0, /* todo_flags_finish */ | |
64 }; | |
65 | |
66 class pass_stack_ptr_mod : public rtl_opt_pass | |
67 { | |
68 public: | |
69 pass_stack_ptr_mod (gcc::context *ctxt) | |
70 : rtl_opt_pass (pass_data_stack_ptr_mod, ctxt) | |
71 {} | |
72 | |
73 /* opt_pass methods: */ | |
74 virtual unsigned int execute (function *); | |
75 | |
76 }; // class pass_stack_ptr_mod | |
77 | |
78 unsigned int | |
79 pass_stack_ptr_mod::execute (function *fun) | |
0 | 80 { |
81 basic_block bb; | |
111 | 82 rtx_insn *insn; |
0 | 83 |
84 /* Assume that the stack pointer is unchanging if alloca hasn't | |
85 been used. */ | |
111 | 86 crtl->sp_is_unchanging = !fun->calls_alloca; |
87 if (crtl->sp_is_unchanging) | |
88 FOR_EACH_BB_FN (bb, fun) | |
0 | 89 FOR_BB_INSNS (bb, insn) |
90 { | |
91 if (INSN_P (insn)) | |
92 { | |
93 /* Check if insn modifies the stack pointer. */ | |
94 note_stores (PATTERN (insn), | |
95 notice_stack_pointer_modification_1, | |
96 NULL); | |
111 | 97 if (! crtl->sp_is_unchanging) |
98 return 0; | |
0 | 99 } |
100 } | |
101 | |
102 /* The value coming into this pass was 0, and the exit block uses | |
103 are based on this. If the value is now 1, we need to redo the | |
104 exit block uses. */ | |
111 | 105 if (df && crtl->sp_is_unchanging) |
0 | 106 df_update_exit_block_uses (); |
107 | |
108 return 0; | |
109 } | |
110 | |
111 | 111 } // anon namespace |
112 | |
113 rtl_opt_pass * | |
114 make_pass_stack_ptr_mod (gcc::context *ctxt) | |
0 | 115 { |
111 | 116 return new pass_stack_ptr_mod (ctxt); |
117 } |