diff -Naurp gcc/config/avr/avr-devices.c gcc/config/avr/avr-devices.c
--- gcc/config/avr/avr-devices.c	2011-10-28 12:00:41.000000000 +0530
+++ gcc/config/avr/avr-devices.c	2011-10-28 12:06:09.000000000 +0530
@@ -272,6 +272,7 @@ const struct mcu_type_s avr_mcu_types[] 
   { "atxmega64a3",  ARCH_AVRXMEGA4, "__AVR_ATxmega64A3__",          0, 0x2000, "x64a3" },
   { "atxmega64a3u", ARCH_AVRXMEGA4, "__AVR_ATxmega64A3U__",         0, 0x2000, "x64a3u"},
   { "atxmega64d3",  ARCH_AVRXMEGA4, "__AVR_ATxmega64D3__",          0, 0x2000, "x64d3" },
+  { "atxmega64d4",  ARCH_AVRXMEGA4, "__AVR_ATxmega64D4__",          0, 0x2000, "x64d4" },
     /* Xmega, > 64K, <= 128K FLASH, > 64K RAM.  */
   { "avrxmega5",    ARCH_AVRXMEGA5, NULL,                           0, 0x2000, "x64a1" },
   { "atxmega64a1",  ARCH_AVRXMEGA5, "__AVR_ATxmega64A1__",          0, 0x2000, "x64a1" },
diff -Naurp gcc/config/avr/t-avr gcc/config/avr/t-avr
--- gcc/config/avr/t-avr	2011-10-28 12:00:41.000000000 +0530
+++ gcc/config/avr/t-avr	2011-10-28 12:04:00.000000000 +0530
@@ -282,6 +282,7 @@ MULTILIB_MATCHES = \
 	mmcu?avrxmega4=mmcu?atxmega64a3 \
 	mmcu?avrxmega4=mmcu?atxmega64a3u \
 	mmcu?avrxmega4=mmcu?atxmega64d3 \
+	mmcu?avrxmega4=mmcu?atxmega64d4 \
 	mmcu?avrxmega5=mmcu?atxmega64a1 \
 	mmcu?avrxmega5=mmcu?atxmega64a1u \
 	mmcu?avrxmega6=mmcu?atxmega128a3 \