vm/jit.cpp

   1 #include "master.hpp"
   2
   3 namespace factor
   4 {
   5
   6 /* Simple code generator used by:
   7 - quotation compiler (quotations.cpp),
   8 - megamorphic caches (dispatch.cpp),
   9 - polymorphic inline caches (inline_cache.cpp) */
  10
  11 /* Allocates memory */
  12 jit::jit(code_block_type type_, cell owner_, factor_vm *vm)
  13         : type(type_),
  14           owner(owner_,vm),
  15           code(vm),
  16           relocation(vm),
  17           parameters(vm),
  18           literals(vm),
  19           computing_offset_p(false),
  20           position(0),
  21           offset(0),
  22           parent(vm)
  23 {
  24         fixnum old_count = atomic::fetch_add(&parent->current_jit_count, 1);
  25         FACTOR_ASSERT(old_count >= 0);
  26         (void)old_count;
  27 }
  28
  29 jit::~jit()
  30 {
  31         fixnum old_count = atomic::fetch_subtract(&parent->current_jit_count, 1);
  32         FACTOR_ASSERT(old_count >= 1);
  33         (void)old_count;
  34 }
  35
  36 void jit::emit_relocation(cell relocation_template_)
  37 {
  38         data_root<byte_array> relocation_template(relocation_template_,parent);
  39         cell capacity = array_capacity(relocation_template.untagged())
  40                 / sizeof(relocation_entry);
  41         relocation_entry *relocations = relocation_template->data<relocation_entry>();
  42         for(cell i = 0; i < capacity; i++)
  43         {
  44                 relocation_entry entry = relocations[i];
  45                 relocation_entry new_entry(entry.rel_type(), entry.rel_class(),
  46                         entry.rel_offset() + code.count);
  47                 relocation.append_bytes(&new_entry,sizeof(relocation_entry));
  48         }
  49 }
  50
  51 /* Allocates memory */
  52 void jit::emit(cell code_template_)
  53 {
  54         data_root<array> code_template(code_template_,parent);
  55
  56         emit_relocation(array_nth(code_template.untagged(),0));
  57
  58         data_root<byte_array> insns(array_nth(code_template.untagged(),1),parent);
  59
  60         if(computing_offset_p)
  61         {
  62                 cell size = array_capacity(insns.untagged());
  63
  64                 if(offset == 0)
  65                 {
  66                         position--;
  67                         computing_offset_p = false;
  68                 }
  69                 else if(offset < size)
  70                 {
  71                         position++;
  72                         computing_offset_p = false;
  73                 }
  74                 else
  75                         offset -= size;
  76         }
  77
  78         code.append_byte_array(insns.value());
  79 }
  80
  81 void jit::emit_with_literal(cell code_template_, cell argument_) {
  82         data_root<array> code_template(code_template_,parent);
  83         data_root<object> argument(argument_,parent);
  84         literal(argument.value());
  85         emit(code_template.value());
  86 }
  87
  88 void jit::emit_with_parameter(cell code_template_, cell argument_) {
  89         data_root<array> code_template(code_template_,parent);
  90         data_root<object> argument(argument_,parent);
  91         parameter(argument.value());
  92         emit(code_template.value());
  93 }
  94
  95 bool jit::emit_subprimitive(cell word_, bool tail_call_p, bool stack_frame_p)
  96 {
  97         data_root<word> word(word_,parent);
  98         data_root<array> code_template(word->subprimitive,parent);
  99         parameters.append(untag<array>(array_nth(code_template.untagged(),0)));
 100         literals.append(untag<array>(array_nth(code_template.untagged(),1)));
 101         emit(array_nth(code_template.untagged(),2));
 102         if(array_capacity(code_template.untagged()) == 5)
 103         {
 104                 if(tail_call_p)
 105                 {
 106                         if(stack_frame_p) emit(parent->special_objects[JIT_EPILOG]);
 107                         emit(array_nth(code_template.untagged(),4));
 108                         return true;
 109                 }
 110                 else
 111                         emit(array_nth(code_template.untagged(),3));
 112         }
 113         return false;
 114 }
 115
 116 /* Facility to convert compiled code offsets to quotation offsets.
 117 Call jit_compute_offset() with the compiled code offset, then emit
 118 code, and at the end jit->position is the quotation position. */
 119 void jit::compute_position(cell offset_)
 120 {
 121         computing_offset_p = true;
 122         position = 0;
 123         offset = offset_;
 124 }
 125
 126 /* Allocates memory */
 127 code_block *jit::to_code_block()
 128 {
 129         /* Emit dummy GC info */
 130         code.grow_bytes(alignment_for(code.count + 4,data_alignment));
 131         u32 dummy_gc_info = 0;
 132         code.append_bytes(&dummy_gc_info,sizeof(u32));
 133
 134         code.trim();
 135         relocation.trim();
 136         parameters.trim();
 137         literals.trim();
 138
 139         return parent->add_code_block(
 140                 type,
 141                 code.elements.value(),
 142                 false_object, /* no labels */
 143                 owner.value(),
 144                 relocation.elements.value(),
 145                 parameters.elements.value(),
 146                 literals.elements.value());
 147 }
 148
 149 }