Messages in this thread Patch in this message | | | From | David Howells <> | Subject | [PATCH 1/7] FRV: Fix fls() to handle bit 31 being set correctly [try #2] | Date | Wed, 13 Sep 2006 18:59:34 +0100 |
| |
From: David Howells <dhowells@redhat.com>
Fix FRV fls() to handle bit 31 being set correctly (it should return 32 not 0).
Signed-Off-By: David Howells <dhowells@redhat.com> ---
include/asm-frv/bitops.h | 21 +++++++++++++++++---- 1 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/include/asm-frv/bitops.h b/include/asm-frv/bitops.h index 980ae1b..97fb746 100644 --- a/include/asm-frv/bitops.h +++ b/include/asm-frv/bitops.h @@ -161,16 +161,29 @@ #include <asm-generic/bitops/ffs.h> #include <asm-generic/bitops/__ffs.h> #include <asm-generic/bitops/find.h> -/* - * fls: find last bit set. +/** + * fls - find last bit set + * @x: the word to search + * + * This is defined the same way as ffs: + * - return 32..1 to indicate bit 31..0 most significant bit set + * - return 0 to indicate no bits set */ #define fls(x) \ ({ \ int bit; \ \ - asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x)); \ + asm(" subcc %1,gr0,gr0,icc0 \n" \ + " ckne icc0,cc4 \n" \ + " cscan.p %1,gr0,%0 ,cc4,#1 \n" \ + " csub %0,%0,%0 ,cc4,#0 \n" \ + " csub %2,%0,%0 ,cc4,#1 \n" \ + : "=&r"(bit) \ + : "r"(x), "r"(32) \ + : "icc0", "cc4" \ + ); \ \ - bit ? 33 - bit : bit; \ + bit; \ }) #include <asm-generic/bitops/fls64.h> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |