Improve constant propagation for Mint and Smi.

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
===================================================================
--- runtime/vm/intermediate_language.cc	(revision 23018)
+++ runtime/vm/intermediate_language.cc	(working copy)
@@ -4,6 +4,7 @@
 
 #include "vm/intermediate_language.h"
 
+#include "vm/bigint_operations.h"
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
@@ -204,6 +205,16 @@
 }
 
 
+ConstantInstr::ConstantInstr(const Object& value) : value_(value) {
+  // Check that the value is not an incorrect Integer representation.
+  ASSERT(!value.IsBigint() ||
+         !BigintOperations::FitsIntoSmi(Bigint::Cast(value)));
+  ASSERT(!value.IsBigint() ||
+         !BigintOperations::FitsIntoInt64(Bigint::Cast(value)));
+  ASSERT(!value.IsMint() || !Smi::IsValid64(Mint::Cast(value).AsInt64Value()));
+}
+
+
 bool ConstantInstr::AttributesEqual(Instruction* other) const {
   ConstantInstr* other_constant = other->AsConstant();
   ASSERT(other_constant != NULL);