Add more generic version of reloc info padding to ensure enough space for rel...

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
===================================================================
--- src/ia32/lithium-codegen-ia32.cc	(revision 6848)
+++ src/ia32/lithium-codegen-ia32.cc	(working copy)
@@ -55,7 +55,9 @@
     // Ensure that we have enough space in the reloc info to patch
     // this with calls when doing deoptimization.
     if (ensure_reloc_space_) {
-      codegen_->masm()->RecordComment(RelocInfo::kFillerCommentString, true);
+      // We can use up to RelocInfo::kMaxCallSize bytes for storing call,
+      // if this includes a long variable length pc-jump.
+      codegen_->AddRelocPadding(RelocInfo::kMaxCallSize);
     }
     codegen_->RecordSafepoint(pointers_, deoptimization_index_);
   }
@@ -78,6 +80,7 @@
   return GeneratePrologue() &&
       GenerateBody() &&
       GenerateDeferredCode() &&
+      GenerateRelocPadding() &&
       GenerateSafepointTable();
 }
 
@@ -122,6 +125,15 @@
 }
 
 
+bool LCodeGen::GenerateRelocPadding() {
+  while(reloc_padding_count_ > 0) {
+    __ RecordComment(RelocInfo::kFillerCommentString, true);
+    reloc_padding_count_ -= RelocInfo::kRelocCommentSize;
+  }
+  return !is_aborted();
+}
+
+
 bool LCodeGen::GeneratePrologue() {
   ASSERT(is_generating());
 
@@ -382,6 +394,13 @@
   ASSERT(instr != NULL);
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());

[Søren Thygesen Gjesse, 2011/02/21 13:27:20]

Move this comment and code to after the '__ call'?

+  // A call will only take up 1 byte in the reloc_info, but patching in the
+  // deoptimizer will take up two since it uses RUNTIME_ENTY as relocation
+  // mode to avoid issues with GC. Any pc-jumps will be the same for both
+  // relocation info objects since we patch at the same spot as the original
+  // call.
+  AddRelocPadding(1);
+
   if (!adjusted) {
     __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
   }
@@ -2302,9 +2321,9 @@
     __ CallSelf();
   } else {
     // This is an indirect call and will not be recorded in the reloc info.
-    // Add a comment to the reloc info in case we need to patch this during
-    // deoptimization.
-    __ RecordComment(RelocInfo::kFillerCommentString, true);
+    // We can use up to RelocInfo::kMaxCallSize bytes for storing call, if
+    // this includes a long variable length pc-jump.
+    AddRelocPadding(RelocInfo::kMaxCallSize);
     __ call(FieldOperand(edi, JSFunction::kCodeEntryOffset));
   }