1768

1 files changed, 110 insertions, 0 deletions

diff --git a/041jump_label.cc b/041jump_label.cc
new file mode 100644
index 00000000..dca2e37a
--- /dev/null
+++ b/041jump_label.cc
@@ -0,0 +1,110 @@
+//: Support jumps to labels.
+//: We'll also treat 'break' and 'continue' as jumps. The choice of name is
+//: just documentation about intent.
+
+:(scenario jump_to_label)
+recipe main [
+  jump +target:label
+  1:number <- copy 0:literal
+  +target
+]
+-mem: storing 0 in location 1
+
+:(before "End Mu Types Initialization")
+Type_ordinal["label"] = 0;
+
+:(after "int main")
+  Transform.push_back(transform_labels);
+
+:(code)
+void transform_labels(const recipe_ordinal r) {
+  map<string, long long int> offset;
+  for (long long int i = 0; i < SIZE(Recipe[r].steps); ++i) {
+    const instruction& inst = Recipe[r].steps.at(i);
+    if (!inst.label.empty()) offset[inst.label] = i;
+  }
+  for (long long int i = 0; i < SIZE(Recipe[r].steps); ++i) {
+    instruction& inst = Recipe[r].steps.at(i);
+    if (inst.operation == Recipe_ordinal["jump"]) {
+//?       cerr << inst.to_string() << '\n'; //? 1
+      replace_offset(inst.ingredients.at(0), offset, i, r);
+    }
+    if (inst.operation == Recipe_ordinal["jump-if"] || inst.operation == Recipe_ordinal["jump-unless"]) {
+      replace_offset(inst.ingredients.at(1), offset, i, r);
+    }
+    if ((inst.operation == Recipe_ordinal["loop"] || inst.operation == Recipe_ordinal["break"])
+        && SIZE(inst.ingredients) == 1) {
+      replace_offset(inst.ingredients.at(0), offset, i, r);
+    }
+    if ((inst.operation == Recipe_ordinal["loop-if"] || inst.operation == Recipe_ordinal["loop-unless"]
+            || inst.operation == Recipe_ordinal["break-if"] || inst.operation == Recipe_ordinal["break-unless"])
+        && SIZE(inst.ingredients) == 2) {
+      replace_offset(inst.ingredients.at(1), offset, i, r);
+    }
+  }
+}
+
+:(code)
+void replace_offset(reagent& x, /*const*/ map<string, long long int>& offset, const long long int current_offset, const recipe_ordinal r) {
+//?   cerr << "AAA " << x.to_string() << '\n'; //? 1
+  assert(is_literal(x));
+//?   cerr << "BBB " << x.to_string() << '\n'; //? 1
+  assert(!x.initialized);
+//?   cerr << "CCC " << x.to_string() << '\n'; //? 1
+  if (is_integer(x.name)) return;  // non-labels will be handled like other number operands
+//?   cerr << "DDD " << x.to_string() << '\n'; //? 1
+  if (offset.find(x.name) == offset.end())
+    raise << "can't find label " << x.name << " in routine " << Recipe[r].name << '\n';
+  x.set_value(offset[x.name]-current_offset);
+}
+
+:(scenario break_to_label)
+recipe main [
+#?   $print [aaa]
+  {
+    {
+      break +target:label
+      1:number <- copy 0:literal
+    }
+  }
+  +target
+]
+-mem: storing 0 in location 1
+
+:(scenario jump_if_to_label)
+recipe main [
+  {
+    {
+      jump-if 1:literal, +target:label
+      1:number <- copy 0:literal
+    }
+  }
+  +target
+]
+-mem: storing 0 in location 1
+
+:(scenario loop_unless_to_label)
+recipe main [
+  {
+    {
+      loop-unless 0:literal, +target:label  # loop/break with a label don't care about braces
+      1:number <- copy 0:literal
+    }
+  }
+  +target
+]
+-mem: storing 0 in location 1
+
+:(scenario jump_runs_code_after_label)
+recipe main [
+  # first a few lines of padding to exercise the offset computation
+  1:number <- copy 0:literal
+  2:number <- copy 0:literal
+  3:number <- copy 0:literal
+  jump +target:label
+  4:number <- copy 0:literal
+  +target
+  5:number <- copy 0:literal
+]
++mem: storing 0 in location 5
+-mem: storing 0 in location 4