Change keyed store IC interface on x64 to take value, key, and receiver in re...

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
===================================================================
--- src/x64/codegen-x64.cc	(revision 4691)
+++ src/x64/codegen-x64.cc	(working copy)
@@ -680,11 +680,51 @@
 
 void DeferredReferenceSetKeyedValue::Generate() {
   __ IncrementCounter(&Counters::keyed_store_inline_miss, 1);
-  // Push receiver and key arguments on the stack.
-  __ push(receiver_);
-  __ push(key_);
-  // Move value argument to eax as expected by the IC stub.
-  if (!value_.is(rax)) __ movq(rax, value_);
+  // Move value, receiver, and key to registers rax, rdx, and rcx, as
+  // the IC stub expects.
+  // Move value to rax, using xchg if the receiver or key is in rax.
+  if (!value_.is(rax)) {
+    if (!receiver_.is(rax) && !key_.is(rax)) {
+      __ movq(rax, value_);
+    } else {
+      __ xchg(rax, value_);
+      // Update receiver_ and key_ if they are affected by the swap.
+      if (receiver_.is(rax)) {
+        receiver_ = value_;
+      } else if (receiver_.is(value_)) {
+        receiver_ = rax;
+      }
+      if (key_.is(rax)) {
+        key_ = value_;
+      } else if (key_.is(value_)) {
+        key_ = rax;
+      }
+    }
+  }
+  // Value is now in rax. Its original location is remembered in value_,
+  // and the value is restored to value_ before returning.
+  // The variables receiver_ and key_ are not preserved.
+  // Move receiver and key to rdx and rcx, swapping if necessary.
+  if (receiver_.is(rdx)) {
+    if (!key_.is(rcx)) {
+      __ movq(rcx, key_);
+    }  // Else everything is already in the right place.
+  } else if (receiver_.is(rcx)) {
+    if (key_.is(rdx)) {
+      __ xchg(rcx, rdx);
+    } else if (key_.is(rcx)) {
+      __ movq(rdx, receiver_);
+    } else {
+      __ movq(rdx, receiver_);
+      __ movq(rcx, key_);
+    }
+  } else if (key_.is(rcx)) {
+    __ movq(rdx, receiver_);
+  } else {
+    __ movq(rcx, key_);
+    __ movq(rdx, receiver_);
+  }
+
   // Call the IC stub.
   Handle<Code> ic(Builtins::builtin(Builtins::KeyedStoreIC_Initialize));
   __ Call(ic, RelocInfo::CODE_TARGET);
@@ -697,11 +737,8 @@
   // Here we use masm_-> instead of the __ macro because this is the
   // instruction that gets patched and coverage code gets in the way.
   masm_->testl(rax, Immediate(-delta_to_patch_site));
-  // Restore value (returned from store IC), key and receiver
-  // registers.
+  // Restore value (returned from store IC).
   if (!value_.is(rax)) __ movq(value_, rax);
-  __ pop(key_);
-  __ pop(receiver_);
 }
 
 
@@ -7533,8 +7570,6 @@
 
         deferred->BindExit();
 
-        cgen_->frame()->Push(&receiver);
-        cgen_->frame()->Push(&key);
         cgen_->frame()->Push(&value);
       } else {
         Result answer = cgen_->frame()->CallKeyedStoreIC();
@@ -7545,7 +7580,7 @@
         masm->nop();
         cgen_->frame()->Push(&answer);
       }
-      cgen_->UnloadReference(this);
+      set_unloaded();
       break;
     }