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-rw-r--r--include/asm-mips/bitops.h58
1 files changed, 32 insertions, 26 deletions
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h
index 3b0c8aaf6e8b..8e802059fe67 100644
--- a/include/asm-mips/bitops.h
+++ b/include/asm-mips/bitops.h
@@ -644,20 +644,26 @@ static inline unsigned long ffz(unsigned long word)
644} 644}
645 645
646/* 646/*
647 * flz - find last zero in word. 647 * fls - find last bit set.
648 * @word: The word to search 648 * @word: The word to search
649 * 649 *
650 * Returns 0..SZLONG-1 650 * Returns 1..SZLONG
651 * Undefined if no zero exists, so code should check against ~0UL first. 651 * Returns 0 if no bit exists
652 */ 652 */
653static inline unsigned long flz(unsigned long word) 653static inline unsigned long fls(unsigned long word)
654{ 654{
655#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
656 return __ilog2(~word);
657#else
658#ifdef CONFIG_32BIT 655#ifdef CONFIG_32BIT
659 int r = 31, s; 656#ifdef CONFIG_CPU_MIPS32
660 word = ~word; 657 __asm__ ("clz %0, %1" : "=r" (word) : "r" (word));
658
659 return 32 - word;
660#else
661 {
662 int r = 32, s;
663
664 if (word == 0)
665 return 0;
666
661 s = 16; if ((word & 0xffff0000)) s = 0; r -= s; word <<= s; 667 s = 16; if ((word & 0xffff0000)) s = 0; r -= s; word <<= s;
662 s = 8; if ((word & 0xff000000)) s = 0; r -= s; word <<= s; 668 s = 8; if ((word & 0xff000000)) s = 0; r -= s; word <<= s;
663 s = 4; if ((word & 0xf0000000)) s = 0; r -= s; word <<= s; 669 s = 4; if ((word & 0xf0000000)) s = 0; r -= s; word <<= s;
@@ -665,10 +671,23 @@ static inline unsigned long flz(unsigned long word)
665 s = 1; if ((word & 0x80000000)) s = 0; r -= s; 671 s = 1; if ((word & 0x80000000)) s = 0; r -= s;
666 672
667 return r; 673 return r;
674 }
668#endif 675#endif
676#endif /* CONFIG_32BIT */
677
669#ifdef CONFIG_64BIT 678#ifdef CONFIG_64BIT
670 int r = 63, s; 679#ifdef CONFIG_CPU_MIPS64
671 word = ~word; 680
681 __asm__ ("dclz %0, %1" : "=r" (word) : "r" (word));
682
683 return 64 - word;
684#else
685 {
686 int r = 64, s;
687
688 if (word == 0)
689 return 0;
690
672 s = 32; if ((word & 0xffffffff00000000UL)) s = 0; r -= s; word <<= s; 691 s = 32; if ((word & 0xffffffff00000000UL)) s = 0; r -= s; word <<= s;
673 s = 16; if ((word & 0xffff000000000000UL)) s = 0; r -= s; word <<= s; 692 s = 16; if ((word & 0xffff000000000000UL)) s = 0; r -= s; word <<= s;
674 s = 8; if ((word & 0xff00000000000000UL)) s = 0; r -= s; word <<= s; 693 s = 8; if ((word & 0xff00000000000000UL)) s = 0; r -= s; word <<= s;
@@ -677,24 +696,11 @@ static inline unsigned long flz(unsigned long word)
677 s = 1; if ((word & 0x8000000000000000UL)) s = 0; r -= s; 696 s = 1; if ((word & 0x8000000000000000UL)) s = 0; r -= s;
678 697
679 return r; 698 return r;
699 }
680#endif 700#endif
681#endif 701#endif /* CONFIG_64BIT */
682} 702}
683 703
684/*
685 * fls - find last bit set.
686 * @word: The word to search
687 *
688 * Returns 1..SZLONG
689 * Returns 0 if no bit exists
690 */
691static inline unsigned long fls(unsigned long word)
692{
693 if (word == 0)
694 return 0;
695
696 return flz(~word) + 1;
697}
698#define fls64(x) generic_fls64(x) 704#define fls64(x) generic_fls64(x)
699 705
700/* 706/*