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comparison gcc/stack-ptr-mod.c @ 111:04ced10e8804

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gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents 77e2b8dfacca
children 84e7813d76e9
comparison
equal deleted inserted replaced
68:561a7518be6b 111:04ced10e8804
1 /* Discover if the stack pointer is modified in a function. 1 /* Discover if the stack pointer is modified in a function.
2 Copyright (C) 2007, 2008, 2009 2 Copyright (C) 2007-2017 Free Software Foundation, Inc.
3 Free Software Foundation, Inc.
4 3
5 This file is part of GCC. 4 This file is part of GCC.
6 5
7 GCC is free software; you can redistribute it and/or modify it under 6 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free 7 the terms of the GNU General Public License as published by the Free
19 <http://www.gnu.org/licenses/>. */ 18 <http://www.gnu.org/licenses/>. */
20 19
21 #include "config.h" 20 #include "config.h"
22 #include "system.h" 21 #include "system.h"
23 #include "coretypes.h" 22 #include "coretypes.h"
24 #include "tm.h" 23 #include "backend.h"
25 #include "tree.h"
26 #include "rtl.h" 24 #include "rtl.h"
27 #include "regs.h" 25 #include "df.h"
28 #include "expr.h" 26 #include "memmodel.h"
27 #include "emit-rtl.h"
29 #include "tree-pass.h" 28 #include "tree-pass.h"
30 #include "basic-block.h"
31 #include "flags.h"
32 #include "output.h"
33 #include "df.h"
34 29
35 /* Determine if the stack pointer is constant over the life of the function. 30 /* Determine if the stack pointer is constant over the life of the function.
36 Only useful before prologues have been emitted. */ 31 Only useful before prologues have been emitted. */
37 32
38 static void 33 static void
44 of a push until later. See the comments in rtl.texi 39 of a push until later. See the comments in rtl.texi
45 regarding Embedded Side-Effects on Addresses. */ 40 regarding Embedded Side-Effects on Addresses. */
46 || (MEM_P (x) 41 || (MEM_P (x)
47 && GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == RTX_AUTOINC 42 && GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == RTX_AUTOINC
48 && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) 43 && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx))
49 current_function_sp_is_unchanging = 0; 44 crtl->sp_is_unchanging = 0;
50 } 45 }
51 46
52 static void 47 /* Some targets can emit simpler epilogues if they know that sp was
53 notice_stack_pointer_modification (void) 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)
54 { 80 {
55 basic_block bb; 81 basic_block bb;
56 rtx insn; 82 rtx_insn *insn;
57 83
58 /* Assume that the stack pointer is unchanging if alloca hasn't 84 /* Assume that the stack pointer is unchanging if alloca hasn't
59 been used. */ 85 been used. */
60 current_function_sp_is_unchanging = !cfun->calls_alloca; 86 crtl->sp_is_unchanging = !fun->calls_alloca;
61 if (current_function_sp_is_unchanging) 87 if (crtl->sp_is_unchanging)
62 FOR_EACH_BB (bb) 88 FOR_EACH_BB_FN (bb, fun)
63 FOR_BB_INSNS (bb, insn) 89 FOR_BB_INSNS (bb, insn)
64 { 90 {
65 if (INSN_P (insn)) 91 if (INSN_P (insn))
66 { 92 {
67 /* Check if insn modifies the stack pointer. */ 93 /* Check if insn modifies the stack pointer. */
68 note_stores (PATTERN (insn), 94 note_stores (PATTERN (insn),
69 notice_stack_pointer_modification_1, 95 notice_stack_pointer_modification_1,
70 NULL); 96 NULL);
71 if (! current_function_sp_is_unchanging) 97 if (! crtl->sp_is_unchanging)
72 return; 98 return 0;
73 } 99 }
74 } 100 }
75 101
76 /* The value coming into this pass was 0, and the exit block uses 102 /* The value coming into this pass was 0, and the exit block uses
77 are based on this. If the value is now 1, we need to redo the 103 are based on this. If the value is now 1, we need to redo the
78 exit block uses. */ 104 exit block uses. */
79 if (df && current_function_sp_is_unchanging) 105 if (df && crtl->sp_is_unchanging)
80 df_update_exit_block_uses (); 106 df_update_exit_block_uses ();
81 }
82 107
83 /* Some targets can emit simpler epilogues if they know that sp was
84 not ever modified during the function. After reload, of course,
85 we've already emitted the epilogue so there's no sense searching. */
86
87 static unsigned int
88 rest_of_handle_stack_ptr_mod (void)
89 {
90 notice_stack_pointer_modification ();
91 return 0; 108 return 0;
92 } 109 }
93 110
94 struct rtl_opt_pass pass_stack_ptr_mod = 111 } // anon namespace
112
113 rtl_opt_pass *
114 make_pass_stack_ptr_mod (gcc::context *ctxt)
95 { 115 {
96 { 116 return new pass_stack_ptr_mod (ctxt);
97 RTL_PASS, 117 }
98 "*stack_ptr_mod", /* name */
99 NULL, /* gate */
100 rest_of_handle_stack_ptr_mod, /* execute */
101 NULL, /* sub */
102 NULL, /* next */
103 0, /* static_pass_number */
104 TV_NONE, /* tv_id */
105 0, /* properties_required */
106 0, /* properties_provided */
107 0, /* properties_destroyed */
108 0, /* todo_flags_start */
109 0 /* todo_flags_finish */
110 }
111 };