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Diffstat (limited to 'meta/packages/gcc/gcc-4.3.0/904-flatten-switch-stmt-00.patch')
-rw-r--r-- | meta/packages/gcc/gcc-4.3.0/904-flatten-switch-stmt-00.patch | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/meta/packages/gcc/gcc-4.3.0/904-flatten-switch-stmt-00.patch b/meta/packages/gcc/gcc-4.3.0/904-flatten-switch-stmt-00.patch new file mode 100644 index 0000000000..8fac37c4df --- /dev/null +++ b/meta/packages/gcc/gcc-4.3.0/904-flatten-switch-stmt-00.patch | |||
@@ -0,0 +1,153 @@ | |||
1 | Hi, | ||
2 | |||
3 | The attached patch makes sure that we create smaller object code for | ||
4 | simple switch statements. We just make sure to flatten the switch | ||
5 | statement into an if-else chain, basically. | ||
6 | |||
7 | This fixes a size-regression as compared to gcc-3.4, as can be seen | ||
8 | below. | ||
9 | |||
10 | 2007-04-15 Bernhard Fischer <..> | ||
11 | |||
12 | * stmt.c (expand_case): Do not create a complex binary tree when | ||
13 | optimizing for size but rather use the simple ordered list. | ||
14 | (emit_case_nodes): do not emit jumps to the default_label when | ||
15 | optimizing for size. | ||
16 | |||
17 | Not regtested so far. | ||
18 | Comments? | ||
19 | |||
20 | Attached is the test switch.c mentioned below. | ||
21 | |||
22 | $ for i in 2.95 3.3 3.4 4.0 4.1 4.2.orig-HEAD 4.3.orig-HEAD 4.3-HEAD;do | ||
23 | gcc-$i -DCHAIN -Os -o switch-CHAIN-$i.o -c switch.c ;done | ||
24 | $ for i in 2.95 3.3 3.4 4.0 4.1 4.2.orig-HEAD 4.3.orig-HEAD 4.3-HEAD;do | ||
25 | gcc-$i -UCHAIN -Os -o switch-$i.o -c switch.c ;done | ||
26 | |||
27 | $ size switch-*.o | ||
28 | text data bss dec hex filename | ||
29 | 169 0 0 169 a9 switch-2.95.o | ||
30 | 115 0 0 115 73 switch-3.3.o | ||
31 | 103 0 0 103 67 switch-3.4.o | ||
32 | 124 0 0 124 7c switch-4.0.o | ||
33 | 124 0 0 124 7c switch-4.1.o | ||
34 | 124 0 0 124 7c switch-4.2.orig-HEAD.o | ||
35 | 95 0 0 95 5f switch-4.3-HEAD.o | ||
36 | 124 0 0 124 7c switch-4.3.orig-HEAD.o | ||
37 | 166 0 0 166 a6 switch-CHAIN-2.95.o | ||
38 | 111 0 0 111 6f switch-CHAIN-3.3.o | ||
39 | 95 0 0 95 5f switch-CHAIN-3.4.o | ||
40 | 95 0 0 95 5f switch-CHAIN-4.0.o | ||
41 | 95 0 0 95 5f switch-CHAIN-4.1.o | ||
42 | 95 0 0 95 5f switch-CHAIN-4.2.orig-HEAD.o | ||
43 | 95 0 0 95 5f switch-CHAIN-4.3-HEAD.o | ||
44 | 95 0 0 95 5f switch-CHAIN-4.3.orig-HEAD.o | ||
45 | |||
46 | |||
47 | Content-Type: text/x-diff; charset=us-ascii | ||
48 | Content-Disposition: attachment; filename="gcc-4.3.gcc-flatten-switch-stmt.00.diff" | ||
49 | |||
50 | Index: gcc-4.2.0/gcc/stmt.c | ||
51 | =================================================================== | ||
52 | --- gcc-4.2.0.orig/gcc/stmt.c (revision 123843) | ||
53 | +++ gcc-4.2.0/gcc/stmt.c (working copy) | ||
54 | @@ -2517,7 +2517,11 @@ expand_case (tree exp) | ||
55 | use_cost_table | ||
56 | = (TREE_CODE (orig_type) != ENUMERAL_TYPE | ||
57 | && estimate_case_costs (case_list)); | ||
58 | - balance_case_nodes (&case_list, NULL); | ||
59 | + /* When optimizing for size, we want a straight list to avoid | ||
60 | + jumps as much as possible. This basically creates an if-else | ||
61 | + chain. */ | ||
62 | + if (!optimize_size) | ||
63 | + balance_case_nodes (&case_list, NULL); | ||
64 | emit_case_nodes (index, case_list, default_label, index_type); | ||
65 | emit_jump (default_label); | ||
66 | } | ||
67 | @@ -3075,6 +3079,7 @@ emit_case_nodes (rtx index, case_node_pt | ||
68 | { | ||
69 | if (!node_has_low_bound (node, index_type)) | ||
70 | { | ||
71 | + if (!optimize_size) /* don't jl to the .default_label. */ | ||
72 | emit_cmp_and_jump_insns (index, | ||
73 | convert_modes | ||
74 | (mode, imode, | ||
75 | |||
76 | |||
77 | Content-Type: text/x-csrc; charset=us-ascii | ||
78 | Content-Disposition: attachment; filename="switch.c" | ||
79 | |||
80 | int | ||
81 | commutative_tree_code (int code) | ||
82 | { | ||
83 | #define CASE(val, ret) case val:/* __asm__("# val="#val ",ret="#ret);*/ return ret; | ||
84 | #ifndef CHAIN | ||
85 | switch (code) | ||
86 | { | ||
87 | # if 1 | ||
88 | CASE(1,3) | ||
89 | CASE(3,2) | ||
90 | CASE(5,8) | ||
91 | CASE(7,1) | ||
92 | CASE(33,4) | ||
93 | CASE(44,9) | ||
94 | CASE(55,10) | ||
95 | CASE(66,-1) | ||
96 | CASE(77,99) | ||
97 | CASE(666,0) | ||
98 | # else | ||
99 | case 1: | ||
100 | return 3; | ||
101 | case 3: | ||
102 | return 2; | ||
103 | case 5: | ||
104 | return 8; | ||
105 | case 7: | ||
106 | return 1; | ||
107 | case 33: | ||
108 | return 4; | ||
109 | case 44: | ||
110 | return 9; | ||
111 | case 55: | ||
112 | return 10; | ||
113 | case 66: | ||
114 | return -1; | ||
115 | case 77: | ||
116 | return 99; | ||
117 | case 666: | ||
118 | return 0; | ||
119 | # endif | ||
120 | default: | ||
121 | break; | ||
122 | } | ||
123 | return 4711; | ||
124 | |||
125 | #else | ||
126 | if (code == 1) | ||
127 | return 3; | ||
128 | else if (code == 3) | ||
129 | return 2; | ||
130 | else if (code == 5) | ||
131 | return 8; | ||
132 | else if (code == 7) | ||
133 | return 1; | ||
134 | else if (code == 33) | ||
135 | return 4; | ||
136 | else if (code == 44) | ||
137 | return 9; | ||
138 | else if (code == 55) | ||
139 | return 10; | ||
140 | else if (code == 66) | ||
141 | return -1; | ||
142 | else if (code == 77) | ||
143 | return 99; | ||
144 | else if (code == 666) | ||
145 | return 0; | ||
146 | else | ||
147 | return 4711; | ||
148 | #endif | ||
149 | } | ||
150 | |||
151 | |||
152 | --AhhlLboLdkugWU4S-- | ||
153 | |||