diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 6968049..9648620 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -240,8 +240,16 @@
 static void DefineExactWidthIntType(TargetInfo::IntType Ty, 
                                const TargetInfo &TI, std::vector<char> &Buf) {
   char MacroBuf[60];
-  sprintf(MacroBuf, "__INT%d_TYPE__", TI.getTypeWidth(Ty));
+  int TypeWidth = TI.getTypeWidth(Ty);
+  sprintf(MacroBuf, "__INT%d_TYPE__", TypeWidth);
   DefineType(MacroBuf, Ty, Buf);
+
+
+  const char *ConstSuffix = TargetInfo::getTypeConstantSuffix(Ty);
+  if (strlen(ConstSuffix) > 0) {
+    sprintf(MacroBuf, "__INT%d_C_SUFFIX__=%s", TypeWidth, ConstSuffix);
+    DefineBuiltinMacro(Buf, MacroBuf);
+  }
 }
 
 static void InitializePredefinedMacros(const TargetInfo &TI,
diff --git a/lib/Headers/stdint.h b/lib/Headers/stdint.h
index b404e3d..419dc0b 100644
--- a/lib/Headers/stdint.h
+++ b/lib/Headers/stdint.h
@@ -247,8 +247,6 @@
 
 
 #ifdef __INT64_TYPE__
-/* FIXME: predefine suffix based on type*/
-# define __INT64_C_SUFFIX__ LL
 # ifdef __INT64_C_SUFFIX__
 #  define __int64_c_suffix __INT64_C_SUFFIX__
 #  define __int32_c_suffix __INT64_C_SUFFIX__
@@ -274,8 +272,6 @@
 
 
 #ifdef __INT56_TYPE__
-/* FIXME: predefine suffix based on type */
-# define __INT56_C_SUFFIX__ L
 # ifdef __INT56_C_SUFFIX__
 #  define INT56_C(v) __int_c(v, __INT56_C_SUFFIX__)
 #  define UINT56_C(v) __uint_c(v, __INT56_C_SUFFIX__)
@@ -293,8 +289,6 @@
 
 
 #ifdef __INT48_TYPE__
-/* FIXME: predefine suffix based on type */
-# define __INT48_C_SUFFIX__ L
 # ifdef __INT48_C_SUFFIX__
 #  define INT48_C(v) __int_c(v, __INT48_C_SUFFIX__)
 #  define UINT48_C(v) __uint_c(v, __INT48_C_SUFFIX__)
@@ -312,8 +306,6 @@
 
 
 #ifdef __INT40_TYPE__
-/* FIXME: predefine suffix based on type */
-# define __INT40_C_SUFFIX__ L
 # ifdef __INT40_C_SUFFIX__
 #  define INT40_C(v) __int_c(v, __INT40_C_SUFFIX__)
 #  define UINT40_C(v) __uint_c(v, __INT40_C_SUFFIX__)
diff --git a/test/Preprocessor/init.c b/test/Preprocessor/init.c
index b88ea06..100e274 100644
--- a/test/Preprocessor/init.c
+++ b/test/Preprocessor/init.c
@@ -155,6 +155,7 @@
 // ARM:#define __FLT_RADIX__ 2
 // ARM:#define __INT16_TYPE__ short
 // ARM:#define __INT32_TYPE__ int
+// ARM:#define __INT64_C_SUFFIX__ LL
 // ARM:#define __INT64_TYPE__ long long int
 // ARM:#define __INT8_TYPE__ char
 // ARM:#define __INTMAX_MAX__ 9223372036854775807LL
@@ -232,6 +233,7 @@
 // BFIN:#define __FLT_RADIX__ 2
 // BFIN:#define __INT16_TYPE__ short
 // BFIN:#define __INT32_TYPE__ int
+// BFIN:#define __INT64_C_SUFFIX__ LL
 // BFIN:#define __INT64_TYPE__ long long int
 // BFIN:#define __INT8_TYPE__ char
 // BFIN:#define __INTMAX_MAX__ 9223372036854775807LL
@@ -302,6 +304,7 @@
 // I386:#define __FLT_RADIX__ 2
 // I386:#define __INT16_TYPE__ short
 // I386:#define __INT32_TYPE__ int
+// I386:#define __INT64_C_SUFFIX__ LL
 // I386:#define __INT64_TYPE__ long long int
 // I386:#define __INT8_TYPE__ char
 // I386:#define __INTMAX_MAX__ 9223372036854775807LL
@@ -378,6 +381,7 @@
 // MSP430:#define __FLT_MIN__ 1.17549435e-38F
 // MSP430:#define __FLT_RADIX__ 2
 // MSP430:#define __INT16_TYPE__ short
+// MSP430:#define __INT32_C_SUFFIX__ L
 // MSP430:#define __INT32_TYPE__ long int
 // MSP430:#define __INT8_TYPE__ char
 // MSP430:#define __INTMAX_MAX__ 2147483647L
@@ -447,6 +451,7 @@
 // PIC16:#define __FLT_MIN__ 1.17549435e-38F
 // PIC16:#define __FLT_RADIX__ 2
 // PIC16:#define __INT16_TYPE__ short
+// PIC16:#define __INT32_C_SUFFIX__ L
 // PIC16:#define __INT32_TYPE__ long int
 // PIC16:#define __INT8_TYPE__ char
 // PIC16:#define __INTMAX_MAX__ 2147483647L
@@ -528,6 +533,7 @@
 // PPC64:#define __FLT_RADIX__ 2
 // PPC64:#define __INT16_TYPE__ short
 // PPC64:#define __INT32_TYPE__ int
+// PPC64:#define __INT64_C_SUFFIX__ L
 // PPC64:#define __INT64_TYPE__ long int
 // PPC64:#define __INT8_TYPE__ char
 // PPC64:#define __INTMAX_MAX__ 9223372036854775807L
@@ -606,6 +612,7 @@
 // PPC:#define __FLT_RADIX__ 2
 // PPC:#define __INT16_TYPE__ short
 // PPC:#define __INT32_TYPE__ int
+// PPC:#define __INT64_C_SUFFIX__ LL
 // PPC:#define __INT64_TYPE__ long long int
 // PPC:#define __INT8_TYPE__ char
 // PPC:#define __INTMAX_MAX__ 9223372036854775807LL
@@ -679,6 +686,7 @@
 // S390X:#define __FLT_RADIX__ 2
 // S390X:#define __INT16_TYPE__ short
 // S390X:#define __INT32_TYPE__ int
+// S390X:#define __INT64_C_SUFFIX__ L
 // S390X:#define __INT64_TYPE__ long int
 // S390X:#define __INT8_TYPE__ char
 // S390X:#define __INTMAX_MAX__ 9223372036854775807LL
@@ -748,6 +756,7 @@
 // SPARC:#define __FLT_RADIX__ 2
 // SPARC:#define __INT16_TYPE__ short
 // SPARC:#define __INT32_TYPE__ int
+// SPARC:#define __INT64_C_SUFFIX__ LL
 // SPARC:#define __INT64_TYPE__ long long int
 // SPARC:#define __INT8_TYPE__ char
 // SPARC:#define __INTMAX_MAX__ 9223372036854775807LL
@@ -893,6 +902,7 @@
 // X86_64:#define __FLT_RADIX__ 2
 // X86_64:#define __INT16_TYPE__ short
 // X86_64:#define __INT32_TYPE__ int
+// X86_64:#define __INT64_C_SUFFIX__ L
 // X86_64:#define __INT64_TYPE__ long int
 // X86_64:#define __INT8_TYPE__ char
 // X86_64:#define __INTMAX_MAX__ 9223372036854775807L
diff --git a/test/Preprocessor/stdint.c b/test/Preprocessor/stdint.c
index 2349c32..faa5f8e 100644
--- a/test/Preprocessor/stdint.c
+++ b/test/Preprocessor/stdint.c
@@ -413,8 +413,8 @@
 // MSP430:UINT8_C_(0) (0U)
 // MSP430:INT16_C_(0) (0)
 // MSP430:UINT16_C_(0) (0U)
-// MSP430:INT32_C_(0) (0)
-// MSP430:UINT32_C_(0) (0U)
+// MSP430:INT32_C_(0) (0L)
+// MSP430:UINT32_C_(0) (0UL)
 // MSP430:INT64_C_(0) INT64_C(0)
 // MSP430:UINT64_C_(0) UINT64_C(0)
 //
@@ -513,8 +513,8 @@
 // PIC16:UINT8_C_(0) (0U)
 // PIC16:INT16_C_(0) (0)
 // PIC16:UINT16_C_(0) (0U)
-// PIC16:INT32_C_(0) (0)
-// PIC16:UINT32_C_(0) (0U)
+// PIC16:INT32_C_(0) (0L)
+// PIC16:UINT32_C_(0) (0UL)
 // PIC16:INT64_C_(0) INT64_C(0)
 // PIC16:UINT64_C_(0) UINT64_C(0)
 //
@@ -622,8 +622,8 @@
 // PPC64:UINT16_C_(0) (0U)
 // PPC64:INT32_C_(0) (0)
 // PPC64:UINT32_C_(0) (0U)
-// PPC64:INT64_C_(0) (0LL)
-// PPC64:UINT64_C_(0) (0ULL)
+// PPC64:INT64_C_(0) (0L)
+// PPC64:UINT64_C_(0) (0UL)
 //
 // PPC64:INTMAX_C_(0) (0LL)
 // PPC64:UINTMAX_C_(0) (0ULL)
@@ -837,8 +837,8 @@
 // S390X:UINT16_C_(0) (0U)
 // S390X:INT32_C_(0) (0)
 // S390X:UINT32_C_(0) (0U)
-// S390X:INT64_C_(0) (0LL)
-// S390X:UINT64_C_(0) (0ULL)
+// S390X:INT64_C_(0) (0L)
+// S390X:UINT64_C_(0) (0UL)
 //
 // S390X:INTMAX_C_(0) (0LL)
 // S390X:UINTMAX_C_(0) (0ULL)
@@ -1152,8 +1152,8 @@
 // X86_64:UINT16_C_(0) (0U)
 // X86_64:INT32_C_(0) (0)
 // X86_64:UINT32_C_(0) (0U)
-// X86_64:INT64_C_(0) (0LL)
-// X86_64:UINT64_C_(0) (0ULL)
+// X86_64:INT64_C_(0) (0L)
+// X86_64:UINT64_C_(0) (0UL)
 //
 // X86_64:INTMAX_C_(0) (0LL)
 // X86_64:UINTMAX_C_(0) (0ULL)