Change OSR stack check patching to use the stack check table.

src/ia32/deoptimizer-ia32.cc

Index: src/ia32/deoptimizer-ia32.cc
diff --git a/src/ia32/deoptimizer-ia32.cc b/src/ia32/deoptimizer-ia32.cc
index e9e3fcfb7f3c6ac5f879f05d4183a16615b1b267..b41dacea7d4645dd2b35b8a22cf03362b1ad37bf 100644
--- a/src/ia32/deoptimizer-ia32.cc
+++ b/src/ia32/deoptimizer-ia32.cc
@@ -106,48 +106,35 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 }
 
 
-void Deoptimizer::PatchStackCheckCode(Code* unoptimized_code,
-                                      Code* check_code,
-                                      Code* replacement_code) {
-  // Iterate the unoptimized code and patch every stack check except at
-  // the function entry.  This code assumes the function entry stack
-  // check appears first i.e., is not deferred or otherwise reordered.
-  ASSERT(unoptimized_code->kind() == Code::FUNCTION);
-  bool first = true;
-  for (RelocIterator it(unoptimized_code, RelocInfo::kCodeTargetMask);
-       !it.done();
-       it.next()) {
-    RelocInfo* rinfo = it.rinfo();
-    if (rinfo->target_address() == Code::cast(check_code)->entry()) {
-      if (first) {
-        first = false;
-      } else {
-        // The stack check code matches the pattern:
-        //
-        //     cmp esp, <limit>
-        //     jae ok
-        //     call <stack guard>
-        //     test eax, <loop nesting depth>
-        // ok: ...
-        //
-        // We will patch away the branch so the code is:
-        //
-        //     cmp esp, <limit>  ;; Not changed
-        //     nop
-        //     nop
-        //     call <on-stack replacment>
-        //     test eax, <loop nesting depth>
-        // ok:
-        Address call_target_address = rinfo->pc();
-        ASSERT(*(call_target_address - 3) == 0x73 &&  // jae
-               *(call_target_address - 2) == 0x07 &&  // offset
-               *(call_target_address - 1) == 0xe8);   // call
-        *(call_target_address - 3) = 0x90;  // nop
-        *(call_target_address - 2) = 0x90;  // nop
-        rinfo->set_target_address(replacement_code->entry());
-      }
-    }
-  }
+void Deoptimizer::PatchStackCheckAt(Address pc_after,
+                                    Code* check_code,
+                                    Code* replacement_code) {
+    Address call_target_address = pc_after - kPointerSize;
+    ASSERT(check_code->entry() ==
+           Assembler::target_address_at(call_target_address));
+    // The stack check code matches the pattern:
+    //
+    //     cmp esp, <limit>
+    //     jae ok
+    //     call <stack guard>
+    //     test eax, <loop nesting depth>
+    // ok: ...
+    //
+    // We will patch away the branch so the code is:
+    //
+    //     cmp esp, <limit>  ;; Not changed
+    //     nop
+    //     nop
+    //     call <on-stack replacment>
+    //     test eax, <loop nesting depth>
+    // ok:
+    ASSERT(*(call_target_address - 3) == 0x73 &&  // jae
+           *(call_target_address - 2) == 0x07 &&  // offset
+           *(call_target_address - 1) == 0xe8);   // call
+    *(call_target_address - 3) = 0x90;  // nop
+    *(call_target_address - 2) = 0x90;  // nop
+    Assembler::set_target_address_at(call_target_address,
+                                     replacement_code->entry());
 }