[Atomics] Make Atomics.exchange a builtin using TF

src/builtins/builtins.h

Index: src/builtins/builtins.h
diff --git a/src/builtins/builtins.h b/src/builtins/builtins.h
index e190ef91b70606e8c71fa44ad966f24ffbe9c6cd..34d5243d73efde941260a2a3e36d85ea399c6572 100644
--- a/src/builtins/builtins.h
+++ b/src/builtins/builtins.h
@@ -49,7 +49,15 @@ class Isolate;
 //      Args: name, code kind, extra IC state
 // DBG: Builtin in platform-dependent assembly, used by the debugger.
 //      Args: name
-#define BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG)                        \
+#if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
+#define ATOMICS_BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG) \
+  CPP(AtomicsExchange)

[Jarin, 2017/03/01 07:45:37]

Rather than special casing here, could you keep the runtime function and let the
mips stub tailcall into the runtime function?

Even better, could you ping v8-mips-ports to help you with the mips part?

[aseemgarg, 2017/03/02 03:26:56]

Put in call to runtime function. Will ping v8-mips-ports once this patch is
submitted.

+#else
+#define ATOMICS_BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG) \
+  TFJ(AtomicsExchange, 3)
+#endif
+
+#define NON_ATOMICS_BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG)            \
   ASM(Abort)                                                                   \
   /* Code aging */                                                             \
   CODE_AGE_LIST_WITH_ARG(DECLARE_CODE_AGE_BUILTIN, ASM)                        \
@@ -847,6 +855,10 @@ class Isolate;
   /* proposal-async-iteration/#sec-async-iterator-value-unwrap-functions */    \
   TFJ(AsyncIteratorValueUnwrap, 1)
 
+#define BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG)       \
+  NON_ATOMICS_BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG) \
+  ATOMICS_BUILTIN_LIST(CPP, API, TFJ, TFS, ASM, ASH, DBG)
+
 #define IGNORE_BUILTIN(...)
 
 #define BUILTIN_LIST_ALL(V) BUILTIN_LIST(V, V, V, V, V, V, V)