gcc/testsuite/jit.dg/test-factorial-must-tail-call.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 #include "libgccjit.h"
   6
   7 #include "harness.h"
   8
   9 void
  10 create_code (gcc_jit_context *ctxt, void *user_data)
  11 {
  12   /* Let's try to inject the equivalent of:
  13
  14       int
  15       my_factorial_must_tail_call (int x)
  16       {
  17         if (x < 2)
  18           return x;
  19         else
  20           return x * my_factorial_must_tail_call (x - 1);
  21       }
  22
  23      and mark the call as requiring tail-call-optimization.
  24    */
  25   gcc_jit_type *the_type =
  26     gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);
  27   gcc_jit_type *return_type = the_type;
  28
  29   gcc_jit_param *x =
  30     gcc_jit_context_new_param (ctxt, NULL, the_type, "x");
  31   gcc_jit_param *params[1] = {x};
  32   gcc_jit_function *func =
  33     gcc_jit_context_new_function (ctxt, NULL,
  34                                   GCC_JIT_FUNCTION_EXPORTED,
  35                                   return_type,
  36                                   "my_factorial_must_tail_call",
  37                                   1, params, 0);
  38
  39   gcc_jit_block *initial =
  40     gcc_jit_function_new_block (func, "initial");
  41   gcc_jit_block *on_true =
  42     gcc_jit_function_new_block (func, "on_true");
  43   gcc_jit_block *on_false =
  44     gcc_jit_function_new_block (func, "on_false");
  45
  46  /* if (x < 2) */
  47   gcc_jit_block_end_with_conditional (
  48     initial, NULL,
  49     gcc_jit_context_new_comparison (
  50       ctxt, NULL,
  51       GCC_JIT_COMPARISON_LT,
  52       gcc_jit_param_as_rvalue (x),
  53       gcc_jit_context_new_rvalue_from_int (
  54         ctxt,
  55         the_type,
  56         2)),
  57     on_true,
  58     on_false);
  59
  60   /* true branch: */
  61   /* return x */
  62   gcc_jit_block_end_with_return (
  63     on_true,
  64     NULL,
  65     gcc_jit_param_as_rvalue (x));
  66
  67   /* false branch: */
  68   gcc_jit_rvalue *x_minus_1 =
  69     gcc_jit_context_new_binary_op (
  70       ctxt, NULL,
  71       GCC_JIT_BINARY_OP_MINUS, the_type,
  72       gcc_jit_param_as_rvalue (x),
  73       gcc_jit_context_new_rvalue_from_int (
  74         ctxt,
  75         the_type,
  76         1));
  77   /* my_factorial_must_tail_call (x - 1) */
  78   gcc_jit_rvalue *call =
  79       gcc_jit_context_new_call (
  80         ctxt, NULL,
  81         func,
  82         1, &x_minus_1);
  83
  84   /* Mark the call as requiring tail-call optimization.  */
  85   gcc_jit_rvalue_set_bool_require_tail_call (call, 1);
  86
  87   gcc_jit_block_end_with_return (
  88     on_false,
  89     NULL,
  90     gcc_jit_context_new_binary_op (
  91       ctxt, NULL,
  92       GCC_JIT_BINARY_OP_MULT, the_type,
  93       gcc_jit_param_as_rvalue (x),
  94       call));
  95 }
  96
  97 void
  98 verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
  99 {
 100   typedef int (*my_factorial_fn_type) (int);
 101   CHECK_NON_NULL (result);
 102   my_factorial_fn_type my_factorial_must_tail_call =
 103     (my_factorial_fn_type)gcc_jit_result_get_code (result, "my_factorial_must_tail_call");
 104   CHECK_NON_NULL (my_factorial_must_tail_call);
 105   int val = my_factorial_must_tail_call (10);
 106   note ("my_factorial_must_tail_call returned: %d", val);
 107   CHECK_VALUE (val, 3628800);
 108 }
 109