src/lib/libjit/t1.dpr

   1 (*
   2 Tutorial 1 - mul_add
   3
   4 Builds and compiles the following function:
   5
   6 int mul_add(int x, int y, int z)
   7 {
   8   return x * y + z;
   9 }
  10 *)
  11 {$IFDEF WIN32}
  12   {$DEFINE MSWINDOWS}
  13 {$ENDIF}
  14
  15 {$IFDEF FPC}
  16   {$MODE OBJFPC}
  17   {$PACKRECORDS C}
  18 {$ENDIF}
  19 program t1;
  20
  21 uses
  22   SysUtils, Classes,
  23   libjit in 'libjit.pas',
  24   libjit_types in 'libjit_types.pas';
  25
  26
  27 var
  28   context: jit_context_t;
  29   params: array [0..2] of jit_type_t;
  30   signature: jit_type_t;
  31   function_: jit_function_t;
  32   x, y, z: jit_value_t;
  33   temp1, temp2: jit_value_t;
  34   arg1, arg2, arg3: jit_int;
  35   args: array [0..2] of Pointer;
  36   res: jit_int;
  37 begin
  38   if (jit_type_int = nil) then raise Exception.Create('fuuuuu (0)');
  39
  40   (* Create a context to hold the JIT's primary state *)
  41   writeln('creating context...');
  42   context := jit_context_create();
  43   if (context = nil) then raise Exception.Create('cannot create jit context');
  44
  45   (* Lock the context while we build and compile the function *)
  46   writeln('starting builder...');
  47   jit_context_build_start(context);
  48
  49   (* Build the function signature *)
  50   writeln('creating signature...');
  51   params[0] := jit_type_int;
  52   params[1] := jit_type_int;
  53   params[2] := jit_type_int;
  54   signature := jit_type_create_signature(jit_abi_cdecl, jit_type_int, @params[0], 3, 1);
  55
  56   (* Create the function object *)
  57   writeln('creating function object...');
  58   function_ := jit_function_create(context, signature);
  59   writeln('freeing signature...');
  60   jit_type_free(signature);
  61
  62   (* Construct the function body *)
  63   writeln('creating function body...');
  64   x := jit_value_get_param(function_, 0);
  65   y := jit_value_get_param(function_, 1);
  66   z := jit_value_get_param(function_, 2);
  67   temp1 := jit_insn_mul(function_, x, y);
  68   temp2 := jit_insn_add(function_, temp1, z);
  69   jit_insn_return(function_, temp2);
  70
  71   (* Compile the function *)
  72   writeln('compiling function...');
  73   jit_function_compile(function_);
  74
  75   (* Unlock the context *)
  76   writeln('finalizing builder...');
  77   jit_context_build_end(context);
  78
  79   (* Execute the function and print the result *)
  80   writeln('executing function...');
  81   arg1 := 3;
  82   arg2 := 5;
  83   arg3 := 2;
  84   args[0] := @arg1;
  85   args[1] := @arg2;
  86   args[2] := @arg3;
  87   jit_function_apply(function_, @args[0], @res);
  88   writeln('mul_add(3, 5, 2) = ', Integer(res));
  89
  90   (* Clean up *)
  91   jit_context_destroy(context);
  92 end.