summaryrefslogtreecommitdiff
path: root/gcc/jit/docs/examples/tut03-sum-of-squares.c
blob: b1595d178ecc7b5aae5b0882c41f64a88e42c085 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/* Usage example for libgccjit.so
   Copyright (C) 2014-2017 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GCC is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include <libgccjit.h>

#include <stdlib.h>
#include <stdio.h>

void
create_code (gcc_jit_context *ctxt)
{
  /*
    Simple sum-of-squares, to test conditionals and looping

    int loop_test (int n)
    {
      int i;
      int sum = 0;
      for (i = 0; i < n ; i ++)
      {
	sum += i * i;
      }
      return sum;
   */
  gcc_jit_type *the_type =
    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);
  gcc_jit_type *return_type = the_type;

  gcc_jit_param *n =
    gcc_jit_context_new_param (ctxt, NULL, the_type, "n");
  gcc_jit_param *params[1] = {n};
  gcc_jit_function *func =
    gcc_jit_context_new_function (ctxt, NULL,
				  GCC_JIT_FUNCTION_EXPORTED,
				  return_type,
				  "loop_test",
				  1, params, 0);

  /* Build locals:  */
  gcc_jit_lvalue *i =
    gcc_jit_function_new_local (func, NULL, the_type, "i");
  gcc_jit_lvalue *sum =
    gcc_jit_function_new_local (func, NULL, the_type, "sum");

  gcc_jit_block *b_initial =
    gcc_jit_function_new_block (func, "initial");
  gcc_jit_block *b_loop_cond =
    gcc_jit_function_new_block (func, "loop_cond");
  gcc_jit_block *b_loop_body =
    gcc_jit_function_new_block (func, "loop_body");
  gcc_jit_block *b_after_loop =
    gcc_jit_function_new_block (func, "after_loop");

  /* sum = 0; */
  gcc_jit_block_add_assignment (
    b_initial, NULL,
    sum,
    gcc_jit_context_zero (ctxt, the_type));

  /* i = 0; */
  gcc_jit_block_add_assignment (
    b_initial, NULL,
    i,
    gcc_jit_context_zero (ctxt, the_type));

  gcc_jit_block_end_with_jump (b_initial, NULL, b_loop_cond);

  /* if (i >= n) */
  gcc_jit_block_end_with_conditional (
    b_loop_cond, NULL,
    gcc_jit_context_new_comparison (
       ctxt, NULL,
       GCC_JIT_COMPARISON_GE,
       gcc_jit_lvalue_as_rvalue (i),
       gcc_jit_param_as_rvalue (n)),
    b_after_loop,
    b_loop_body);

  /* sum += i * i */
  gcc_jit_block_add_assignment_op (
    b_loop_body, NULL,
    sum,
    GCC_JIT_BINARY_OP_PLUS,
    gcc_jit_context_new_binary_op (
      ctxt, NULL,
      GCC_JIT_BINARY_OP_MULT, the_type,
      gcc_jit_lvalue_as_rvalue (i),
      gcc_jit_lvalue_as_rvalue (i)));

  /* i++ */
  gcc_jit_block_add_assignment_op (
    b_loop_body, NULL,
    i,
    GCC_JIT_BINARY_OP_PLUS,
    gcc_jit_context_one (ctxt, the_type));

  gcc_jit_block_end_with_jump (b_loop_body, NULL, b_loop_cond);

  /* return sum */
  gcc_jit_block_end_with_return (
    b_after_loop,
    NULL,
    gcc_jit_lvalue_as_rvalue (sum));
}

int
main (int argc, char **argv)
{
  gcc_jit_context *ctxt = NULL;
  gcc_jit_result *result = NULL;

  /* Get a "context" object for working with the library.  */
  ctxt = gcc_jit_context_acquire ();
  if (!ctxt)
    {
      fprintf (stderr, "NULL ctxt");
      goto error;
    }

  /* Set some options on the context.
     Let's see the code being generated, in assembler form.  */
  gcc_jit_context_set_bool_option (
    ctxt,
    GCC_JIT_BOOL_OPTION_DUMP_GENERATED_CODE,
    0);

  /* Populate the context.  */
  create_code (ctxt);

  /* Compile the code.  */
  result = gcc_jit_context_compile (ctxt);
  if (!result)
    {
      fprintf (stderr, "NULL result");
      goto error;
    }

  /* Extract the generated code from "result".  */
  typedef int (*loop_test_fn_type) (int);
  loop_test_fn_type loop_test =
    (loop_test_fn_type)gcc_jit_result_get_code (result, "loop_test");
  if (!loop_test)
    {
      fprintf (stderr, "NULL loop_test");
      goto error;
    }

  /* Run the generated code.  */
  int val = loop_test (10);
  printf("loop_test returned: %d\n", val);

 error:
  gcc_jit_context_release (ctxt);
  gcc_jit_result_release (result);
  return 0;
}