From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57641) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SxwuS-0003GO-Rc for qemu-devel@nongnu.org; Sun, 05 Aug 2012 05:14:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SxwuR-0000Xq-FV for qemu-devel@nongnu.org; Sun, 05 Aug 2012 05:14:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3573) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SxwuR-0000Xd-67 for qemu-devel@nongnu.org; Sun, 05 Aug 2012 05:14:03 -0400 From: Orit Wasserman Date: Sun, 5 Aug 2012 12:13:18 +0300 Message-Id: <1344158004-10370-6-git-send-email-owasserm@redhat.com> In-Reply-To: <1344158004-10370-1-git-send-email-owasserm@redhat.com> References: <1344158004-10370-1-git-send-email-owasserm@redhat.com> Subject: [Qemu-devel] [PATCH 05/11] Add uleb encoding/decoding functions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, aliguori@us.ibm.com, quintela@redhat.com, stefanha@gmail.com, mdroth@linux.vnet.ibm.com, lcapitulino@redhat.com, blauwirbel@gmail.com, Orit Wasserman , chegu_vinod@hp.com, avi@redhat.com, pbonzini@redhat.com, eblake@redhat.com Implement Unsigned Little Endian Base 128. Signed-off-by: Orit Wasserman --- cutils.c | 33 +++++++++++++++++++++++++++++++++ qemu-common.h | 8 ++++++++ 2 files changed, 41 insertions(+), 0 deletions(-) diff --git a/cutils.c b/cutils.c index b0bdd4b..700f943 100644 --- a/cutils.c +++ b/cutils.c @@ -384,3 +384,36 @@ int64_t pow2floor(int64_t value) } return value; } + +/* + * Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128) + * Input is limited to 14-bit numbers + */ +int uleb128_encode_small(uint8_t *out, uint32_t n) +{ + g_assert(n <= 0x3fff); + if (n < 0x80) { + *out++ = n; + return 1; + } else { + *out++ = (n & 0x7f) | 0x80; + *out++ = n >> 7; + return 2; + } +} + +int uleb128_decode_small(const uint8_t *in, uint32_t *n) +{ + if (!(*in & 0x80)) { + *n = *in++; + return 1; + } else { + *n = *in++ & 0x7f; + /* we exceed 14 bit number */ + if (*in & 0x80) { + return -1; + } + *n |= *in++ << 7; + return 2; + } +} diff --git a/qemu-common.h b/qemu-common.h index 855f242..93d1c63 100644 --- a/qemu-common.h +++ b/qemu-common.h @@ -426,4 +426,12 @@ int64_t pow2floor(int64_t value); #include "module.h" +/* + * Implementation of ULEB128 (http://en.wikipedia.org/wiki/LEB128) + * Input is limited to 14-bit numbers + */ + +int uleb128_encode_small(uint8_t *out, uint32_t n); +int uleb128_decode_small(const uint8_t *in, uint32_t *n); + #endif -- 1.7.7.6