Initial patch for a64.

src/checks.h

Index: src/checks.h
diff --git a/src/checks.h b/src/checks.h
index d0a0c2b5acf5da52e3f2c49d3138b62904fa34df..1379763c469da306dedcdd40489ad25cf9ef552c 100644
--- a/src/checks.h
+++ b/src/checks.h
@@ -33,6 +33,9 @@
 #include "../include/v8stdint.h"
 extern "C" void V8_Fatal(const char* file, int line, const char* format, ...);
 
+// Define custom A64 preprocessor helpers to facilitate development.
+#ifndef V8_TARGET_ARCH_A64
+
 // The FATAL, UNREACHABLE and UNIMPLEMENTED macros are useful during
 // development, but they should not be relied on in the final product.
 #ifdef DEBUG
@@ -50,6 +53,71 @@ extern "C" void V8_Fatal(const char* file, int line, const char* format, ...);
 #define UNREACHABLE() ((void) 0)
 #endif
 
+#else
+
+  #ifdef DEBUG
+    #define FATAL(msg)                                                         \
+      V8_Fatal(__FILE__, __LINE__, "%s", (msg))
+    #define UNREACHABLE()                                                      \
+      V8_Fatal(__FILE__, __LINE__, "unreachable code")
+    #else
+    #define FATAL(msg)                                                         \
+      V8_Fatal("", 0, "%s", (msg))
+    #define UNREACHABLE() ((void) 0)
+  #endif
+
+  #define ABORT() printf("in %s, line %i, %s", __FILE__, __LINE__, __func__); \
+    abort()
+
+  #define ALIGNMENT_EXCEPTION() printf("ALIGNMENT EXCEPTION\t"); ABORT()
+
+  // Helpers for unimplemented sections.
+  #define UNIMPLEMENTED()                                                      \
+    do {                                                                       \
+      printf("UNIMPLEMENTED: %s, line %d, %s\n",                               \
+             __FILE__, __LINE__, __func__);                                    \
+      V8_Fatal(__FILE__, __LINE__, "unimplemented code");                      \
+    } while (0)
+  #define UNIMPLEMENTED_M(message)                                             \
+    do {                                                                       \
+      printf("UNIMPLEMENTED: %s, line %d, %s : %s\n",                          \
+             __FILE__, __LINE__, __func__, message);                           \
+      V8_Fatal(__FILE__, __LINE__, "unimplemented code");                      \
+    } while (0)
+  // Like UNIMPLEMENTED, but does not abort.
+  #define TODO_UNIMPLEMENTED(message)                                          \
+      do {                                                                     \
+        static const unsigned int kLimit = 1;                                  \
+        static unsigned int printed = 0;                                       \
+        if (printed < UINT_MAX) {                                              \
+          printed++;                                                           \
+        }                                                                      \
+        if (printed <= kLimit) {                                               \
+          printf("UNIMPLEMENTED: %s, line %d, %s: %s\n",                       \
+                 __FILE__, __LINE__, __func__, message);                       \
+        }                                                                      \
+      } while (0)
+
+  // Simulator specific helpers.
+  #ifdef USE_SIMULATOR
+    // Helpers for unimplemented sections.
+    // TODO(all): If possible automatically prepend an indicator like
+    // UNIMPLEMENTED or LOCATION.
+    #define ASM_UNIMPLEMENTED(message)                                         \
+    __ Debug(message, __LINE__, NO_PARAM)
+    #define ASM_UNIMPLEMENTED_BREAK(message)                                   \
+    __ Debug(message, __LINE__,                                                \
+             FLAG_ignore_asm_unimplemented_break ? NO_PARAM : BREAK)
+    #define ASM_LOCATION(message)                                              \
+    __ Debug("LOCATION: " message, __LINE__, NO_PARAM)
+  #else
+    #define ASM_UNIMPLEMENTED(message)
+    #define ASM_UNIMPLEMENTED_BREAK(message)
+    #define ASM_LOCATION(message)
+  #endif
+
+#endif
+
 
 // The CHECK macro checks that the given condition is true; if not, it
 // prints a message to stderr and aborts.