1 files changed, 19 insertions, 16 deletions

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index a08c33a26ca9..2878811c6134 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -137,9 +137,12 @@ extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 )
 
+#define small_const_nbits(nbits) \
+        (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
+
 static inline void bitmap_zero(unsigned long *dst, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = 0UL;
         else {
                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
@@ -150,7 +153,7 @@ static inline void bitmap_zero(unsigned long *dst, int nbits)
 static inline void bitmap_fill(unsigned long *dst, int nbits)
 {
         size_t nlongs = BITS_TO_LONGS(nbits);
-        if (nlongs > 1) {
+        if (!small_const_nbits(nbits)) {
                 int len = (nlongs - 1) * sizeof(unsigned long);
                 memset(dst, 0xff,  len);
         }
@@ -160,7 +163,7 @@ static inline void bitmap_fill(unsigned long *dst, int nbits)
 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
                         int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = *src;
         else {
                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
@@ -171,7 +174,7 @@ static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = *src1 & *src2;
         else
                 __bitmap_and(dst, src1, src2, nbits);
@@ -180,7 +183,7 @@ static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = *src1 | *src2;
         else
                 __bitmap_or(dst, src1, src2, nbits);
@@ -189,7 +192,7 @@ static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = *src1 ^ *src2;
         else
                 __bitmap_xor(dst, src1, src2, nbits);
@@ -198,7 +201,7 @@ static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = *src1 & ~(*src2);
         else
                 __bitmap_andnot(dst, src1, src2, nbits);
@@ -207,7 +210,7 @@ static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
                         int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
         else
                 __bitmap_complement(dst, src, nbits);
@@ -216,7 +219,7 @@ static inline void bitmap_complement(unsigned long *dst, const unsigned long *sr
 static inline int bitmap_equal(const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
         else
                 return __bitmap_equal(src1, src2, nbits);
@@ -225,7 +228,7 @@ static inline int bitmap_equal(const unsigned long *src1,
 static inline int bitmap_intersects(const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
         else
                 return __bitmap_intersects(src1, src2, nbits);
@@ -234,7 +237,7 @@ static inline int bitmap_intersects(const unsigned long *src1,
 static inline int bitmap_subset(const unsigned long *src1,
                         const unsigned long *src2, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
         else
                 return __bitmap_subset(src1, src2, nbits);
@@ -242,7 +245,7 @@ static inline int bitmap_subset(const unsigned long *src1,
 
 static inline int bitmap_empty(const unsigned long *src, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
         else
                 return __bitmap_empty(src, nbits);
@@ -250,7 +253,7 @@ static inline int bitmap_empty(const unsigned long *src, int nbits)
 
 static inline int bitmap_full(const unsigned long *src, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
         else
                 return __bitmap_full(src, nbits);
@@ -258,7 +261,7 @@ static inline int bitmap_full(const unsigned long *src, int nbits)
 
 static inline int bitmap_weight(const unsigned long *src, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
         return __bitmap_weight(src, nbits);
 }
@@ -266,7 +269,7 @@ static inline int bitmap_weight(const unsigned long *src, int nbits)
 static inline void bitmap_shift_right(unsigned long *dst,
                         const unsigned long *src, int n, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = *src >> n;
         else
                 __bitmap_shift_right(dst, src, n, nbits);
@@ -275,7 +278,7 @@ static inline void bitmap_shift_right(unsigned long *dst,
 static inline void bitmap_shift_left(unsigned long *dst,
                         const unsigned long *src, int n, int nbits)
 {
-        if (nbits <= BITS_PER_LONG)
+        if (small_const_nbits(nbits))
                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
         else
                 __bitmap_shift_left(dst, src, n, nbits);