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authorRalf Baechle <ralf@linux-mips.org>2008-10-28 09:40:35 +0000
committerRalf Baechle <ralf@linux-mips.org>2008-10-30 14:44:33 +0000
commit4816227b54d2366cba785e6f3b9f81495b83a5f1 (patch)
tree3be9118a02aa0b83407212f8b95615be226d1e48 /arch
parentc46b302b948e2070cb713171207c42e9586f131a (diff)
downloadlinux-linaro-stable-4816227b54d2366cba785e6f3b9f81495b83a5f1.tar.gz
MIPS: Clean up MIPSxx-optimized bitop functions
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/include/asm/bitops.h114
1 files changed, 76 insertions, 38 deletions
diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index 49df8c4c9d25..bac4a960b24c 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -558,39 +558,67 @@ static inline void __clear_bit_unlock(unsigned long nr, volatile unsigned long *
__clear_bit(nr, addr);
}
-#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
-
/*
* Return the bit position (0..63) of the most significant 1 bit in a word
* Returns -1 if no 1 bit exists
*/
-static inline unsigned long __fls(unsigned long x)
+static inline unsigned long __fls(unsigned long word)
{
- int lz;
+ int num;
- if (sizeof(x) == 4) {
+ if (BITS_PER_LONG == 32 &&
+ __builtin_constant_p(cpu_has_mips_r) && cpu_has_mips_r) {
__asm__(
" .set push \n"
" .set mips32 \n"
" clz %0, %1 \n"
" .set pop \n"
- : "=r" (lz)
- : "r" (x));
+ : "=r" (num)
+ : "r" (word));
- return 31 - lz;
+ return 31 - num;
}
- BUG_ON(sizeof(x) != 8);
+ if (BITS_PER_LONG == 64 &&
+ __builtin_constant_p(cpu_has_mips64) && cpu_has_mips64) {
+ __asm__(
+ " .set push \n"
+ " .set mips64 \n"
+ " dclz %0, %1 \n"
+ " .set pop \n"
+ : "=r" (num)
+ : "r" (word));
- __asm__(
- " .set push \n"
- " .set mips64 \n"
- " dclz %0, %1 \n"
- " .set pop \n"
- : "=r" (lz)
- : "r" (x));
+ return 63 - num;
+ }
+
+ num = BITS_PER_LONG - 1;
- return 63 - lz;
+#if BITS_PER_LONG == 64
+ if (!(word & (~0ul << 32))) {
+ num -= 32;
+ word <<= 32;
+ }
+#endif
+ if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
+ num -= 16;
+ word <<= 16;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
+ num -= 8;
+ word <<= 8;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
+ num -= 4;
+ word <<= 4;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
+ num -= 2;
+ word <<= 2;
+ }
+ if (!(word & (~0ul << (BITS_PER_LONG-1))))
+ num -= 1;
+ return num;
}
/*
@@ -612,23 +640,43 @@ static inline unsigned long __ffs(unsigned long word)
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static inline int fls(int word)
+static inline int fls(int x)
{
- __asm__("clz %0, %1" : "=r" (word) : "r" (word));
+ int r;
- return 32 - word;
-}
+ if (__builtin_constant_p(cpu_has_mips_r) && cpu_has_mips_r) {
+ __asm__("clz %0, %1" : "=r" (x) : "r" (x));
-#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPS64)
-static inline int fls64(__u64 word)
-{
- __asm__("dclz %0, %1" : "=r" (word) : "r" (word));
+ return 32 - x;
+ }
- return 64 - word;
+ r = 32;
+ if (!x)
+ return 0;
+ if (!(x & 0xffff0000u)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xff000000u)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xf0000000u)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xc0000000u)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x80000000u)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
}
-#else
+
#include <asm-generic/bitops/fls64.h>
-#endif
/*
* ffs - find first bit set.
@@ -646,16 +694,6 @@ static inline int ffs(int word)
return fls(word & -word);
}
-#else
-
-#include <asm-generic/bitops/__ffs.h>
-#include <asm-generic/bitops/__fls.h>
-#include <asm-generic/bitops/ffs.h>
-#include <asm-generic/bitops/fls.h>
-#include <asm-generic/bitops/fls64.h>
-
-#endif /*defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64) */
-
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/find.h>