1 /* Usage example for libgccjit.so
2 Copyright (C) 2014-2020 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
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10
11 GCC is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License 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 <libgccjit.h>
21
22 #include <stdlib.h>
23 #include <stdio.h>
24
25 void
create_code(gcc_jit_context * ctxt)26 create_code (gcc_jit_context *ctxt)
27 {
28 /*
29 Simple sum-of-squares, to test conditionals and looping
30
31 int loop_test (int n)
32 {
33 int i;
34 int sum = 0;
35 for (i = 0; i < n ; i ++)
36 {
37 sum += i * i;
38 }
39 return sum;
40 */
41 gcc_jit_type *the_type =
42 gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);
43 gcc_jit_type *return_type = the_type;
44
45 gcc_jit_param *n =
46 gcc_jit_context_new_param (ctxt, NULL, the_type, "n");
47 gcc_jit_param *params[1] = {n};
48 gcc_jit_function *func =
49 gcc_jit_context_new_function (ctxt, NULL,
50 GCC_JIT_FUNCTION_EXPORTED,
51 return_type,
52 "loop_test",
53 1, params, 0);
54
55 /* Build locals: */
56 gcc_jit_lvalue *i =
57 gcc_jit_function_new_local (func, NULL, the_type, "i");
58 gcc_jit_lvalue *sum =
59 gcc_jit_function_new_local (func, NULL, the_type, "sum");
60
61 gcc_jit_block *b_initial =
62 gcc_jit_function_new_block (func, "initial");
63 gcc_jit_block *b_loop_cond =
64 gcc_jit_function_new_block (func, "loop_cond");
65 gcc_jit_block *b_loop_body =
66 gcc_jit_function_new_block (func, "loop_body");
67 gcc_jit_block *b_after_loop =
68 gcc_jit_function_new_block (func, "after_loop");
69
70 /* sum = 0; */
71 gcc_jit_block_add_assignment (
72 b_initial, NULL,
73 sum,
74 gcc_jit_context_zero (ctxt, the_type));
75
76 /* i = 0; */
77 gcc_jit_block_add_assignment (
78 b_initial, NULL,
79 i,
80 gcc_jit_context_zero (ctxt, the_type));
81
82 gcc_jit_block_end_with_jump (b_initial, NULL, b_loop_cond);
83
84 /* if (i >= n) */
85 gcc_jit_block_end_with_conditional (
86 b_loop_cond, NULL,
87 gcc_jit_context_new_comparison (
88 ctxt, NULL,
89 GCC_JIT_COMPARISON_GE,
90 gcc_jit_lvalue_as_rvalue (i),
91 gcc_jit_param_as_rvalue (n)),
92 b_after_loop,
93 b_loop_body);
94
95 /* sum += i * i */
96 gcc_jit_block_add_assignment_op (
97 b_loop_body, NULL,
98 sum,
99 GCC_JIT_BINARY_OP_PLUS,
100 gcc_jit_context_new_binary_op (
101 ctxt, NULL,
102 GCC_JIT_BINARY_OP_MULT, the_type,
103 gcc_jit_lvalue_as_rvalue (i),
104 gcc_jit_lvalue_as_rvalue (i)));
105
106 /* i++ */
107 gcc_jit_block_add_assignment_op (
108 b_loop_body, NULL,
109 i,
110 GCC_JIT_BINARY_OP_PLUS,
111 gcc_jit_context_one (ctxt, the_type));
112
113 gcc_jit_block_end_with_jump (b_loop_body, NULL, b_loop_cond);
114
115 /* return sum */
116 gcc_jit_block_end_with_return (
117 b_after_loop,
118 NULL,
119 gcc_jit_lvalue_as_rvalue (sum));
120 }
121
122 int
main(int argc,char ** argv)123 main (int argc, char **argv)
124 {
125 gcc_jit_context *ctxt = NULL;
126 gcc_jit_result *result = NULL;
127
128 /* Get a "context" object for working with the library. */
129 ctxt = gcc_jit_context_acquire ();
130 if (!ctxt)
131 {
132 fprintf (stderr, "NULL ctxt");
133 goto error;
134 }
135
136 /* Set some options on the context.
137 Let's see the code being generated, in assembler form. */
138 gcc_jit_context_set_bool_option (
139 ctxt,
140 GCC_JIT_BOOL_OPTION_DUMP_GENERATED_CODE,
141 0);
142
143 /* Populate the context. */
144 create_code (ctxt);
145
146 /* Compile the code. */
147 result = gcc_jit_context_compile (ctxt);
148 if (!result)
149 {
150 fprintf (stderr, "NULL result");
151 goto error;
152 }
153
154 /* Extract the generated code from "result". */
155 typedef int (*loop_test_fn_type) (int);
156 loop_test_fn_type loop_test =
157 (loop_test_fn_type)gcc_jit_result_get_code (result, "loop_test");
158 if (!loop_test)
159 {
160 fprintf (stderr, "NULL loop_test");
161 goto error;
162 }
163
164 /* Run the generated code. */
165 int val = loop_test (10);
166 printf("loop_test returned: %d\n", val);
167
168 error:
169 gcc_jit_context_release (ctxt);
170 gcc_jit_result_release (result);
171 return 0;
172 }
173