Index: cfe/trunk/lib/Headers/popcntintrin.h
===================================================================
--- cfe/trunk/lib/Headers/popcntintrin.h
+++ cfe/trunk/lib/Headers/popcntintrin.h
@@ -27,12 +27,32 @@
 /* Define the default attributes for the functions in this file. */
 #define __DEFAULT_FN_ATTRS __attribute__((__always_inline__, __nodebug__, __target__("popcnt")))
 
+/// \brief Counts the number of bits in the source operand having a value of 1.
+///
+/// \headerfile <x86intrin.h>
+///
+/// This intrinsic corresponds to the \c POPCNT instruction.
+///
+/// \param __A
+///    An unsigned 32-bit integer operand.
+/// \returns A 32-bit integer containing the number of bits with value 1 in the
+///    source operand.
 static __inline__ int __DEFAULT_FN_ATTRS
 _mm_popcnt_u32(unsigned int __A)
 {
   return __builtin_popcount(__A);
 }
 
+/// \brief Counts the number of bits in the source operand having a value of 1.
+///
+/// \headerfile <x86intrin.h>
+///
+/// This intrinsic corresponds to the \c POPCNT instruction.
+///
+/// \param __A
+///    A signed 32-bit integer operand.
+/// \returns A 32-bit integer containing the number of bits with value 1 in the
+///    source operand.
 static __inline__ int __DEFAULT_FN_ATTRS
 _popcnt32(int __A)
 {
@@ -40,12 +60,32 @@
 }
 
 #ifdef __x86_64__
+/// \brief Counts the number of bits in the source operand having a value of 1.
+///
+/// \headerfile <x86intrin.h>
+///
+/// This intrinsic corresponds to the \c POPCNT instruction.
+///
+/// \param __A
+///    An unsigned 64-bit integer operand.
+/// \returns A 64-bit integer containing the number of bits with value 1 in the
+///    source operand.
 static __inline__ long long __DEFAULT_FN_ATTRS
 _mm_popcnt_u64(unsigned long long __A)
 {
   return __builtin_popcountll(__A);
 }
 
+/// \brief Counts the number of bits in the source operand having a value of 1.
+///
+/// \headerfile <x86intrin.h>
+///
+/// This intrinsic corresponds to the \c POPCNT instruction.
+///
+/// \param __A
+///    A signed 64-bit integer operand.
+/// \returns A 64-bit integer containing the number of bits with value 1 in the
+///    source operand.
 static __inline__ long long __DEFAULT_FN_ATTRS
 _popcnt64(long long __A)
 {