From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Date: Tue, 21 Jun 2011 16:33:20 -0500 Subject: [U-Boot] [PATCH 2/5] arm: add __ilog2 function In-Reply-To: <1308692003-2488-1-git-send-email-robherring2@gmail.com> References: <1308692003-2488-1-git-send-email-robherring2@gmail.com> Message-ID: <1308692003-2488-3-git-send-email-robherring2@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de From: Rob Herring Add __ilog2 function for ARM. Needed for ahci.c Signed-off-by: Rob Herring Cc: Albert ARIBAUD --- arch/arm/include/asm/bitops.h | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h index 270f163..0420182 100644 --- a/arch/arm/include/asm/bitops.h +++ b/arch/arm/include/asm/bitops.h @@ -106,6 +106,15 @@ static inline int test_bit(int nr, const void * addr) return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7)); } +extern __inline__ int __ilog2(unsigned int x) +{ + int ret; + + asm("clz\t%0, %1" : "=r" (ret) : "r" (x)); + ret = 31 - ret; + return ret; +} + /* * ffz = Find First Zero in word. Undefined if no zero exists, * so code should check against ~0UL first.. -- 1.7.4.1