From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46343) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WV5gx-0000pf-8T for qemu-devel@nongnu.org; Tue, 01 Apr 2014 16:54:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WV5gr-0007Wb-4r for qemu-devel@nongnu.org; Tue, 01 Apr 2014 16:53:55 -0400 Received: from mail-qc0-x22c.google.com ([2607:f8b0:400d:c01::22c]:33278) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WV5gr-0007WM-0J for qemu-devel@nongnu.org; Tue, 01 Apr 2014 16:53:49 -0400 Received: by mail-qc0-f172.google.com with SMTP id i8so11492992qcq.31 for ; Tue, 01 Apr 2014 13:53:48 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Tue, 1 Apr 2014 13:53:29 -0700 Message-Id: <1396385614-19267-5-git-send-email-rth@twiddle.net> In-Reply-To: <1396385614-19267-1-git-send-email-rth@twiddle.net> References: <1396385614-19267-1-git-send-email-rth@twiddle.net> Subject: [Qemu-devel] [PATCH v2 4/9] tcg: Introduce byte pointer arithmetic helpers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org Signed-off-by: Richard Henderson --- tcg/tcg.h | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/tcg/tcg.h b/tcg/tcg.h index f7efcb4..8df1641 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -717,6 +717,51 @@ TCGv_i32 tcg_const_local_i32(int32_t val); TCGv_i64 tcg_const_local_i64(int64_t val); /** + * tcg_ptr_byte_diff + * @a, @b: addresses to be differenced + * + * There are many places within the TCG backends where we need a byte + * difference between two pointers. While this can be accomplished + * with local casting, it's easy to get wrong -- especially if one is + * concerned with the signedness of the result. + * + * This version relies on GCC's void pointer arithmetic to get the + * correct result. + */ + +static inline ptrdiff_t tcg_ptr_byte_diff(void *a, void *b) +{ + return a - b; +} + +/** + * tcg_pcrel_diff + * @s: the tcg context + * @target: address of the target + * + * Produce a pc-relative difference, from the current code_ptr + * to the destination address. + */ + +static inline ptrdiff_t tcg_pcrel_diff(TCGContext *s, void *target) +{ + return tcg_ptr_byte_diff(target, s->code_ptr); +} + +/** + * tcg_current_code_size + * @s: the tcg context + * + * Compute the current code size within the translation block. + * This is used to fill in qemu's data structures for goto_tb. + */ + +static inline size_t tcg_current_code_size(TCGContext *s) +{ + return tcg_ptr_byte_diff(s->code_ptr, s->code_buf); +} + +/** * tcg_qemu_tb_exec: * @env: CPUArchState * for the CPU * @tb_ptr: address of generated code for the TB to execute -- 1.9.0