vm/jit.cpp

   1 #include "master.hpp"
   2
   3 namespace factor
   4 {
   5
   6 /* Simple code generator used by:
   7 - profiler (profiler.cpp),
   8 - quotation compiler (quotations.cpp),
   9 - megamorphic caches (dispatch.cpp),
  10 - polymorphic inline caches (inline_cache.cpp) */
  11
  12 /* Allocates memory */
  13 jit::jit(code_block_type type_, cell owner_, factor_vm *vm)
  14         : type(type_),
  15           owner(owner_,vm),
  16           code(vm),
  17           relocation(vm),
  18           parameters(vm),
  19           literals(vm),
  20           computing_offset_p(false),
  21           position(0),
  22           offset(0),
  23           parent(vm)
  24 {}
  25
  26 void jit::emit_relocation(cell relocation_template_)
  27 {
  28         data_root<byte_array> relocation_template(relocation_template_,parent);
  29         cell capacity = array_capacity(relocation_template.untagged())
  30                 / sizeof(relocation_entry);
  31         relocation_entry *relocations = relocation_template->data<relocation_entry>();
  32         for(cell i = 0; i < capacity; i++)
  33         {
  34                 relocation_entry entry = relocations[i];
  35                 relocation_entry new_entry(entry.rel_type(), entry.rel_class(),
  36                         entry.rel_offset() + code.count);
  37                 relocation.append_bytes(&new_entry,sizeof(relocation_entry));
  38         }
  39 }
  40
  41 /* Allocates memory */
  42 void jit::emit(cell code_template_)
  43 {
  44         data_root<array> code_template(code_template_,parent);
  45
  46         emit_relocation(array_nth(code_template.untagged(),0));
  47
  48         data_root<byte_array> insns(array_nth(code_template.untagged(),1),parent);
  49
  50         if(computing_offset_p)
  51         {
  52                 cell size = array_capacity(insns.untagged());
  53
  54                 if(offset == 0)
  55                 {
  56                         position--;
  57                         computing_offset_p = false;
  58                 }
  59                 else if(offset < size)
  60                 {
  61                         position++;
  62                         computing_offset_p = false;
  63                 }
  64                 else
  65                         offset -= size;
  66         }
  67
  68         code.append_byte_array(insns.value());
  69 }
  70
  71 void jit::emit_with_literal(cell code_template_, cell argument_) {
  72         data_root<array> code_template(code_template_,parent);
  73         data_root<object> argument(argument_,parent);
  74         literal(argument.value());
  75         emit(code_template.value());
  76 }
  77
  78 void jit::emit_with_parameter(cell code_template_, cell argument_) {
  79         data_root<array> code_template(code_template_,parent);
  80         data_root<object> argument(argument_,parent);
  81         parameter(argument.value());
  82         emit(code_template.value());
  83 }
  84
  85 bool jit::emit_subprimitive(cell word_, bool tail_call_p, bool stack_frame_p)
  86 {
  87         data_root<word> word(word_,parent);
  88         data_root<array> code_template(word->subprimitive,parent);
  89         parameters.append(untag<array>(array_nth(code_template.untagged(),0)));
  90         literals.append(untag<array>(array_nth(code_template.untagged(),1)));
  91         emit(array_nth(code_template.untagged(),2));
  92         if(array_capacity(code_template.untagged()) == 5)
  93         {
  94                 if(tail_call_p)
  95                 {
  96                         if(stack_frame_p) emit(parent->special_objects[JIT_EPILOG]);
  97                         emit(array_nth(code_template.untagged(),4));
  98                         return true;
  99                 }
 100                 else
 101                         emit(array_nth(code_template.untagged(),3));
 102         }
 103         return false;
 104 }
 105
 106 /* Facility to convert compiled code offsets to quotation offsets.
 107 Call jit_compute_offset() with the compiled code offset, then emit
 108 code, and at the end jit->position is the quotation position. */
 109 void jit::compute_position(cell offset_)
 110 {
 111         computing_offset_p = true;
 112         position = 0;
 113         offset = offset_;
 114 }
 115
 116 /* Allocates memory */
 117 code_block *jit::to_code_block()
 118 {
 119         /* Emit dummy GC info */
 120         code.grow_bytes(alignment_for(code.count + 4,data_alignment));
 121         u32 dummy_gc_info = 0;
 122         code.append_bytes(&dummy_gc_info,sizeof(u32));
 123
 124         code.trim();
 125         relocation.trim();
 126         parameters.trim();
 127         literals.trim();
 128
 129         return parent->add_code_block(
 130                 type,
 131                 code.elements.value(),
 132                 false_object, /* no labels */
 133                 owner.value(),
 134                 relocation.elements.value(),
 135                 parameters.elements.value(),
 136                 literals.elements.value());
 137 }
 138
 139 }