From b5c6dc35f9a6623c39e74b925087fa54ea1ca7fe Mon Sep 17 00:00:00 2001
From: "iposva@chromium.org"
 <iposva@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Fri, 15 May 2009 22:36:26 +0000
Subject: [PATCH] - Fix numeric overflow handling when compiling count
 operations.   In certain situations the overflow checking corrupted the value
   being calculated.

Review URL: http://codereview.chromium.org/115423

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1978 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/ia32/codegen-ia32.cc | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index dd14f1b..4a988fe 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -115,6 +115,14 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
 
   JumpTarget::set_compiling_deferred_code(false);
 
+#ifdef DEBUG
+  if (strlen(FLAG_stop_at) > 0 &&
+      fun->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
+    frame_->SpillAll();
+    __ int3();
+  }
+#endif
+  
   {
     HistogramTimerScope codegen_timer(&Counters::code_generation);
     CodeGenState state(this);
@@ -128,14 +136,6 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
     allocator_->Initialize();
     frame_->Enter();
 
-#ifdef DEBUG
-    if (strlen(FLAG_stop_at) > 0 &&
-        fun->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
-      frame_->SpillAll();
-      __ int3();
-    }
-#endif
-
     // Allocate space for locals and initialize them.
     frame_->AllocateStackSlots(scope_->num_stack_slots());
     // Initialize the function return target after the locals are set
@@ -4878,9 +4878,9 @@ void CodeGenerator::VisitCountOperation(CountOperation* node) {
     // successfully allocate a temporary byte register.
     if (tmp.is_valid()) {
       __ setcc(overflow, tmp.reg());
-      __ or_(Operand(value.reg()), tmp.reg());
+      __ or_(Operand(tmp.reg()), value.reg());
+      __ test(tmp.reg(), Immediate(kSmiTagMask));
       tmp.Unuse();
-      __ test(value.reg(), Immediate(kSmiTagMask));
       deferred->enter()->Branch(not_zero, &value, not_taken);
     } else {  // Otherwise we test separately for overflow and smi check.
       deferred->enter()->Branch(overflow, &value, not_taken);
-- 
2.7.4