Fix Issue 1234.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index ffb4632f952c0089be7feb47e218a0a6cd1a72d4..8225c7909d23707b641f03b347f229672a487099 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -39,7 +39,7 @@ namespace internal {
 
 // When invoking builtins, we need to record the safepoint in the middle of
 // the invoke instruction sequence generated by the macro assembler.
-class SafepointGenerator : public PostCallGenerator {
+class SafepointGenerator : public CallWrapper {
  public:
   SafepointGenerator(LCodeGen* codegen,
                      LPointerMap* pointers,
@@ -48,29 +48,29 @@ class SafepointGenerator : public PostCallGenerator {
       : codegen_(codegen),
         pointers_(pointers),
         deoptimization_index_(deoptimization_index),
-        ensure_reloc_space_(ensure_reloc_space),
-        previous_safepoint_position_(-kMinSafepointSize) { }
+        ensure_reloc_space_(ensure_reloc_space) { }
   virtual ~SafepointGenerator() { }
 
-  virtual void Generate() {
+  virtual void BeforeCall(int call_size) {
+    ASSERT(call_size >= 0);
     // Ensure that we have enough space after the previous safepoint position
-    // for the generated code there.
-    int position = codegen_->masm()->pc_offset();
-    ASSERT(position > previous_safepoint_position_);
-    if (position < previous_safepoint_position_ + kMinSafepointSize) {
-      int padding_size =
-          previous_safepoint_position_ + kMinSafepointSize - position;
+    // for the jump generated there.
+    int call_end = codegen_->masm()->pc_offset() + call_size;
+    int prev_jump_end = codegen_->LastSafepointEnd() + kMinSafepointSize;
+    if (call_end < prev_jump_end) {
+      int padding_size = prev_jump_end - call_end;
       STATIC_ASSERT(kMinSafepointSize <= 9);  // One multibyte nop is enough.
       codegen_->masm()->nop(padding_size);
-      position += padding_size;
     }
+  }
+
+  virtual void AfterCall() {
     // 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);
     }
     codegen_->RecordSafepoint(pointers_, deoptimization_index_);
-    previous_safepoint_position_ = position;
   }
 
  private:
@@ -80,7 +80,6 @@ class SafepointGenerator : public PostCallGenerator {
   LPointerMap* pointers_;
   int deoptimization_index_;
   bool ensure_reloc_space_;
-  int previous_safepoint_position_;
 };