From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.axis.com (smtp1.axis.com [195.60.68.17]) by sourceware.org (Postfix) with ESMTPS id 5F2303858D32 for ; Tue, 14 Mar 2023 01:25:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 5F2303858D32 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=axis.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=axis.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1678757139; x=1710293139; h=from:to:subject:mime-version:content-transfer-encoding: message-id:date; bh=/G24/iSgninutqhYh8tuGJf2OjLr0zffELY4iHRl2cY=; b=mXdzE6dLuEa5ctq28guN/r/OWPSY4HXia+BdHpzADgEEda05uuEYJ5iC TwvTsF5CGrQR/lWqlwf+HKQepmZ6yN0+Dvj6AxpNARl6cjpcoI6aKygLq o9C+RlFdccTzzY9GUOsYOilWgEuSRyWMAbLutnQ+M6UY836Jf/U/D8T5H jpdoDe5eQMko/8+pjy0W4lDaUNH4mtOIkyZjs+nTdm70fgclYcs6y2Zb1 JizZ/x0Oisun1S7BO5H3uXt/OqZdHz5cYK7HiSaMb6znHvNpm9hYQigCl dnnaBHU/AGstXUrE61GcYppk0wyOW1C5WravzH/6OcVcW9ZK2GYfw9VDD g==; From: Hans-Peter Nilsson To: , Subject: [PATCH] doc: md.texi (Insn Splitting): Tweak wording for readability. MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-ID: <20230314012536.2789120417@pchp3.se.axis.com> Date: Tue, 14 Mar 2023 02:25:36 +0100 X-Spam-Status: No, score=-8.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,MEDICAL_SUBJECT,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Jan, did I get this right? This was from your r0-36413-g6b24c25948265c / svn r44249, now on its 22nd year! I spot-checked the pdf for readability. Also calling on a doc maintainer to check grammos etc. Ok to commit? -- >8 -- I needed to check what was allowed in a define_split, but had problems understanding what was meant by "Splitting of jump instruction into sequence that over by another jump instruction". * doc/md.texi (Insn Splitting): Tweak wording for readability. --- gcc/doc/md.texi | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index 8e3113599fdc..786365143179 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -8756,21 +8756,21 @@ insns that don't. Instead, write two separate @code{define_split} definitions, one for the insns that are valid and one for the insns that are not valid. -The splitter is allowed to split jump instructions into sequence of -jumps or create new jumps in while splitting non-jump instructions. As -the control flow graph and branch prediction information needs to be updated, -several restriction apply. - -Splitting of jump instruction into sequence that over by another jump -instruction is always valid, as compiler expect identical behavior of new -jump. When new sequence contains multiple jump instructions or new labels, -more assistance is needed. Splitter is required to create only unconditional -jumps, or simple conditional jump instructions. Additionally it must attach a -@code{REG_BR_PROB} note to each conditional jump. A global variable -@code{split_branch_probability} holds the probability of the original branch in case -it was a simple conditional jump, @minus{}1 otherwise. To simplify -recomputing of edge frequencies, the new sequence is required to have only -forward jumps to the newly created labels. +The splitter is allowed to split jump instructions into a sequence of jumps or +create new jumps while splitting non-jump instructions. As the control flow +graph and branch prediction information needs to be updated, several +restrictions apply. + +Splitting of a jump instruction into a sequence that has another jump +instruction is always valid, as the compiler expects identical behavior of the +new jump. When the new sequence contains multiple jump instructions or new +labels, more assistance is needed. The splitter is required to create only +unconditional jumps, or simple conditional jump instructions. Additionally it +must attach a @code{REG_BR_PROB} note to each conditional jump. A global +variable @code{split_branch_probability} holds the probability of the original +branch in case it was a simple conditional jump, @minus{}1 otherwise. To +simplify recomputing of edge frequencies, the new sequence is required to have +only forward jumps to the newly created labels. @findex define_insn_and_split For the common case where the pattern of a define_split exactly matches the -- 2.30.2