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authorRusty Russell <rusty@rustcorp.com.au>2008-12-30 09:05:13 +1030
committerRusty Russell <rusty@rustcorp.com.au>2008-12-30 09:05:13 +1030
commit4b0bc0bca83f3fb7cf920e2ec80684c15d2269c0 (patch)
treeb0a76e8b3d6e505deeaf5c1eba4db18c3ee20f35
parent278d1ed65e25d80af7c3a112d707b3f70516ddb4 (diff)
bitmap: test for constant as well as small size for inline versions
Impact: reduce text size bitmap_zero et al have a fastpath for nbits <= BITS_PER_LONG, but this should really only apply where the nbits is known at compile time. This only saves about 1200 bytes on an allyesconfig kernel, but with cpumasks going variable that number will increase. text data bss dec hex filename 35327852 5035607 6782976 47146435 2cf65c3 vmlinux-before 35326640 5035607 6782976 47145223 2cf6107 vmlinux-after Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
-rw-r--r--include/linux/bitmap.h35
1 files changed, 19 insertions, 16 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index a08c33a26ca..2878811c613 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);