Add tool to visualize machine code/lithium.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 31630d14118a3c617d1b28a801863f5574fc92e8..22eb3a55cb00d498f4970de1d041bfaa746c3810 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -741,6 +741,13 @@ void HInstruction::InsertBefore(HInstruction* next) {
   next_ = next;
   previous_ = prev;
   SetBlock(next->block());
+  if (position() == RelocInfo::kNoPosition) {
+    if (next->position() != RelocInfo::kNoPosition) {
+      set_position(next->position());
+    } else {
+      ASSERT(next->position() == RelocInfo::kNoPosition);

[Michael Starzinger, 2013/10/18 13:04:21]

nit: This if cascade looks awfully complex, especially because this ASSERT will
always hold. Can we merge that into just one if-statement?

[danno, 2013/10/19 17:11:40]

Done.

+    }
+  }
 }
 
 
@@ -775,6 +782,13 @@ void HInstruction::InsertAfter(HInstruction* previous) {
   if (block->last() == previous) {
     block->set_last(this);
   }
+  if (position() == RelocInfo::kNoPosition) {
+    if (previous->position() != RelocInfo::kNoPosition) {
+      set_position(previous->position());
+    } else {
+      ASSERT(previous->position() == RelocInfo::kNoPosition);

[Michael Starzinger, 2013/10/18 13:04:21]

nit: Likewise.

[Michael Starzinger, 2013/10/18 13:04:21]

nit: Likewise.

[danno, 2013/10/19 17:11:40]

Done.

[danno, 2013/10/19 17:11:40]

Done.

+    }
+  }
 }
 
 
@@ -1592,6 +1606,11 @@ Range* HConstant::InferRange(Zone* zone) {
 }
 
 
+int HPhi::position() const {
+  return block()->first()->position();
+}
+
+
 Range* HPhi::InferRange(Zone* zone) {
   Representation r = representation();
   if (r.IsSmiOrInteger32()) {