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authorAndi Kleen <andi@firstfloor.org>2009-01-12 17:01:15 -0500
committerIngo Molnar <mingo@elte.hu>2009-01-13 12:56:30 -0500
commitc8399943bdb70fef78798b97f975506ecc99e039 (patch)
tree3d7cdf853bdfc012b9ea8513ab775238b94d6f75 /include
parent4a922a969cb0190ce4580d4b064e2ac35f3ac9bf (diff)
x86, generic: mark complex bitops.h inlines as __always_inline
Impact: reduce kernel image size Hugh Dickins noticed that older gcc versions when the kernel is built for code size didn't inline some of the bitops. Mark all complex x86 bitops that have more than a single asm statement or two as always inline to avoid this problem. Probably should be done for other architectures too. Ingo then found a better fix that only requires a single line change, but it unfortunately only works on gcc 4.3. On older gccs the original patch still makes a ~0.3% defconfig difference with CONFIG_OPTIMIZE_INLINING=y. With gcc 4.1 and a defconfig like build: 6116998 1138540 883788 8139326 7c323e vmlinux-oi-with-patch 6137043 1138540 883788 8159371 7c808b vmlinux-optimize-inlining ~20k / 0.3% difference. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r--include/asm-generic/bitops/__ffs.h2
-rw-r--r--include/asm-generic/bitops/__fls.h2
-rw-r--r--include/asm-generic/bitops/fls.h2
-rw-r--r--include/asm-generic/bitops/fls64.h4
4 files changed, 5 insertions, 5 deletions
diff --git a/include/asm-generic/bitops/__ffs.h b/include/asm-generic/bitops/__ffs.h
index 9a3274aecf83..937d7c435575 100644
--- a/include/asm-generic/bitops/__ffs.h
+++ b/include/asm-generic/bitops/__ffs.h
@@ -9,7 +9,7 @@
9 * 9 *
10 * Undefined if no bit exists, so code should check against 0 first. 10 * Undefined if no bit exists, so code should check against 0 first.
11 */ 11 */
12static inline unsigned long __ffs(unsigned long word) 12static __always_inline unsigned long __ffs(unsigned long word)
13{ 13{
14 int num = 0; 14 int num = 0;
15 15
diff --git a/include/asm-generic/bitops/__fls.h b/include/asm-generic/bitops/__fls.h
index be24465403d6..a60a7ccb6782 100644
--- a/include/asm-generic/bitops/__fls.h
+++ b/include/asm-generic/bitops/__fls.h
@@ -9,7 +9,7 @@
9 * 9 *
10 * Undefined if no set bit exists, so code should check against 0 first. 10 * Undefined if no set bit exists, so code should check against 0 first.
11 */ 11 */
12static inline unsigned long __fls(unsigned long word) 12static __always_inline unsigned long __fls(unsigned long word)
13{ 13{
14 int num = BITS_PER_LONG - 1; 14 int num = BITS_PER_LONG - 1;
15 15
diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h
index 850859bc5069..0576d1f42f43 100644
--- a/include/asm-generic/bitops/fls.h
+++ b/include/asm-generic/bitops/fls.h
@@ -9,7 +9,7 @@
9 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 9 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
10 */ 10 */
11 11
12static inline int fls(int x) 12static __always_inline int fls(int x)
13{ 13{
14 int r = 32; 14 int r = 32;
15 15
diff --git a/include/asm-generic/bitops/fls64.h b/include/asm-generic/bitops/fls64.h
index 86d403f8b256..b097cf8444e3 100644
--- a/include/asm-generic/bitops/fls64.h
+++ b/include/asm-generic/bitops/fls64.h
@@ -15,7 +15,7 @@
15 * at position 64. 15 * at position 64.
16 */ 16 */
17#if BITS_PER_LONG == 32 17#if BITS_PER_LONG == 32
18static inline int fls64(__u64 x) 18static __always_inline int fls64(__u64 x)
19{ 19{
20 __u32 h = x >> 32; 20 __u32 h = x >> 32;
21 if (h) 21 if (h)
@@ -23,7 +23,7 @@ static inline int fls64(__u64 x)
23 return fls(x); 23 return fls(x);
24} 24}
25#elif BITS_PER_LONG == 64 25#elif BITS_PER_LONG == 64
26static inline int fls64(__u64 x) 26static __always_inline int fls64(__u64 x)
27{ 27{
28 if (x == 0) 28 if (x == 0)
29 return 0; 29 return 0;