Compute assigned variables and dominance frontiers.

runtime/vm/zone.h

Index: runtime/vm/zone.h
diff --git a/runtime/vm/zone.h b/runtime/vm/zone.h
index 8c5677a3ccd7770ea0950321ef0f02b8bccead29..291d44f7653f12e216b7cc92d46a898d56e234e4 100644
--- a/runtime/vm/zone.h
+++ b/runtime/vm/zone.h
@@ -108,6 +108,12 @@ class Zone : public StackResource {
   // allocating new segments of memory on demand using 'new'.
   uword Allocate(intptr_t size) { return zone_.Allocate(size); }
 
+  // Allocate space for an array of 'length' elements of type T.
+  template <typename T>
+  T* AllocateArray(intptr_t length) {
+    return reinterpret_cast<T*>(Allocate(length * sizeof(T)));
+  }

[srdjan, 2012/05/12 00:00:55]

Remove this code. Do the appropriate allocation computation in BitVector
instead.

[Kevin Millikin (Google), 2012/05/15 11:51:44]

OK, but I'm not sure why.  Avoiding reinterpret_cast and sizeof at the call site
seems like the perfect use of a simple convenience function, and I'd rather not
have to write the same type twice in the expression.

[srdjan, 2012/05/15 22:05:32]

I think there is only one place that needs it, therefore no need to  have it in
a library.

+
   // Allocate 'new_size' bytes of memory and copies 'old_size' bytes from
   // 'data' into new allocated memory. Uses current zone.
   uword Reallocate(uword data, intptr_t old_size, intptr_t new_size) {