Add constraints verification to LAllocator::MarkAsCall().

src/lithium-allocator.cc

Index: src/lithium-allocator.cc
diff --git a/src/lithium-allocator.cc b/src/lithium-allocator.cc
index fb24cc1bf94dcf3b1ea5e1817fdc20a82612cbe5..d40604f12212d250196c5a2c3150d3055d8c8659 100644
--- a/src/lithium-allocator.cc
+++ b/src/lithium-allocator.cc
@@ -1586,7 +1586,25 @@ RegisterKind LAllocator::RequiredRegisterKind(int virtual_register) const {
 
 
 void LAllocator::MarkAsCall() {
-  current_summary()->MarkAsCall();
+  // Call instructions can use only fixed registers as
+  // temporaries and outputs because all registers
+  // are blocked by the calling convention.
+  // Inputs can use either fixed register or have a short lifetime (be
+  // used at start of the instruction).
+  InstructionSummary* summary = current_summary();
+  ASSERT(summary->Output() == NULL ||
+         LUnallocated::cast(summary->Output())->HasFixedPolicy() ||

[Kevin Millikin (Chromium), 2011/01/04 11:21:23]

You could define a predicate on LUnallocated:

bool HasFlexibleRegisterPolicy() {
  return HasRegisterPolicy() && !HasFixedPolicy();
}

And use it (negated) in three places here.

+         !LUnallocated::cast(summary->Output())->HasRegisterPolicy());
+  for (int i = 0; i < summary->InputCount(); i++) {
+    ASSERT(LUnallocated::cast(summary->InputAt(i))->HasFixedPolicy() ||

[Kevin Millikin (Chromium), 2011/01/04 11:21:23]

I'd prefer to have the for loops wrapped in #ifdef DEBUG so there's clearly no
code in release builds.

+           LUnallocated::cast(summary->InputAt(i))->IsUsedAtStart() ||
+           !LUnallocated::cast(summary->InputAt(i))->HasRegisterPolicy());
+  }
+  for (int i = 0; i < summary->TempCount(); i++) {
+    ASSERT(LUnallocated::cast(summary->TempAt(i))->HasFixedPolicy() ||
+           !LUnallocated::cast(summary->TempAt(i))->HasRegisterPolicy());
+  }
+  summary->MarkAsCall();
 }