From d7290b6b6e21ab2341d26fba3ec6f00cb32ebab9 Mon Sep 17 00:00:00 2001
From: "lrn@chromium.org"
 <lrn@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Fri, 19 Dec 2008 12:08:29 +0000
Subject: [PATCH] Instead of jumping over a conditional backtrack, jump to a
 single instance somewhere else.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1007 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/regexp-macro-assembler-ia32.cc | 13 +++++++++----
 src/regexp-macro-assembler-ia32.h  |  1 +
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/regexp-macro-assembler-ia32.cc b/src/regexp-macro-assembler-ia32.cc
index 2fa23bcf16..29d9d31f7b 100644
--- a/src/regexp-macro-assembler-ia32.cc
+++ b/src/regexp-macro-assembler-ia32.cc
@@ -93,6 +93,7 @@ RegExpMacroAssemblerIA32::RegExpMacroAssemblerIA32(
       entry_label_(),
       start_label_(),
       success_label_(),
+      backtrack_label_(),
       exit_label_(),
       self_(Heap::undefined_value()) {
   __ jmp(&entry_label_);   // We'll write the entry code later.
@@ -106,6 +107,7 @@ RegExpMacroAssemblerIA32::~RegExpMacroAssemblerIA32() {
   entry_label_.Unuse();
   start_label_.Unuse();
   success_label_.Unuse();
+  backtrack_label_.Unuse();
   exit_label_.Unuse();
   check_preempt_label_.Unuse();
 }
@@ -564,6 +566,12 @@ Handle<Object> RegExpMacroAssemblerIA32::GetCode(Handle<String> source) {
   __ pop(esi);
   __ ret(0);
 
+  // Backtrack code (branch target for conditional backtracks).
+  if (backtrack_label_.is_linked()) {
+    __ bind(&backtrack_label_);
+    Backtrack();
+  }
+
   // Preempt-code
   if (check_preempt_label_.is_linked()) {
     __ bind(&check_preempt_label_);
@@ -818,10 +826,7 @@ void RegExpMacroAssemblerIA32::BranchOrBacktrack(Condition condition,
     return;
   }
   if (to == NULL) {
-    Label skip;
-    __ j(NegateCondition(condition), &skip);
-    Backtrack();
-    __ bind(&skip);
+    __ j(condition, &backtrack_label_);
     return;
   }
   __ j(condition, to);
diff --git a/src/regexp-macro-assembler-ia32.h b/src/regexp-macro-assembler-ia32.h
index d639a2eef4..95ff01a109 100644
--- a/src/regexp-macro-assembler-ia32.h
+++ b/src/regexp-macro-assembler-ia32.h
@@ -201,6 +201,7 @@ class RegExpMacroAssemblerIA32: public RegExpMacroAssembler {
   Label entry_label_;
   Label start_label_;
   Label success_label_;
+  Label backtrack_label_;
   Label exit_label_;
   Label check_preempt_label_;
   // Handle used to represent the generated code object itself.