From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51796) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJT3B-0004ia-8k for qemu-devel@nongnu.org; Tue, 10 Sep 2013 14:52:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VJT38-0005Kt-F7 for qemu-devel@nongnu.org; Tue, 10 Sep 2013 14:52:33 -0400 Received: from 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.d.1.0.0.b.8.0.1.0.0.2.ip6.arpa ([2001:8b0:1d0::1]:43707 helo=mnementh.archaic.org.uk) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJT38-00056X-24 for qemu-devel@nongnu.org; Tue, 10 Sep 2013 14:52:30 -0400 From: Peter Maydell Date: Tue, 10 Sep 2013 19:51:56 +0100 Message-Id: <1378839142-7726-3-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1378839142-7726-1-git-send-email-peter.maydell@linaro.org> References: <1378839142-7726-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PULL 02/28] target-arm: Use sextract32() in branch decode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org In the decode of ARM B and BL insns, swap the order of the "append 2 implicit zeros to imm24" and the sign extend, and use the new sextract32() utility function to do the latter. This avoids a direct dependency on the undefined C behaviour of shifting into the sign bit of an integer. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1378391908-22137-2-git-send-email-peter.maydell@linaro.org --- target-arm/translate.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/target-arm/translate.c b/target-arm/translate.c index 4f4a0a9..8bcfaf3 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -28,6 +28,7 @@ #include "disas/disas.h" #include "tcg-op.h" #include "qemu/log.h" +#include "qemu/bitops.h" #include "helper.h" #define GEN_HELPER 1 @@ -7957,8 +7958,8 @@ static void disas_arm_insn(CPUARMState * env, DisasContext *s) tcg_gen_movi_i32(tmp, val); store_reg(s, 14, tmp); } - offset = (((int32_t)insn << 8) >> 8); - val += (offset << 2) + 4; + offset = sextract32(insn << 2, 0, 26); + val += offset + 4; gen_jmp(s, val); } break; -- 1.7.9.5