From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by sourceware.org (Postfix) with ESMTP id 982433A1B40C for ; Fri, 13 Nov 2020 08:19:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 982433A1B40C Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 56BE0142F for ; Fri, 13 Nov 2020 00:19:17 -0800 (PST) Received: from localhost (e121540-lin.manchester.arm.com [10.32.98.126]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F3D6A3F718 for ; Fri, 13 Nov 2020 00:19:16 -0800 (PST) From: Richard Sandiford To: gcc-patches@gcc.gnu.org Mail-Followup-To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: [15/23] recog: Add a validate_change_xveclen function References: Date: Fri, 13 Nov 2020 08:19:15 +0000 In-Reply-To: (Richard Sandiford's message of "Fri, 13 Nov 2020 08:10:54 +0000") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Nov 2020 08:19:19 -0000 A later patch wants to be able to use the validate_change machinery to reduce the XVECLEN of a PARALLEL. This should be more efficient than allocating a separate PARALLEL at a possibly distant memory location, especially since the new PARALLEL would be garbage rtl if the new pattern turns out not to match. Combine already pulls this trick with SUBST_INT. This patch adds a general helper for doing that. gcc/ * recog.h (validate_change_xveclen): Declare. * recog.c (change_t::old_len): New field. (validate_change_1): Add a new_len parameter. Conditionally replace the XVECLEN of an rtx, avoiding single-element PARALLELs. (validate_change_xveclen): New function. (cancel_changes): Undo changes made by validate_change_xveclen. --- gcc/recog.c | 41 +++++++++++++++++++++++++++++++++++------ gcc/recog.h | 1 + 2 files changed, 36 insertions(+), 6 deletions(-) diff --git a/gcc/recog.c b/gcc/recog.c index 2d934169a81..65125b8f0d1 100644 --- a/gcc/recog.c +++ b/gcc/recog.c @@ -183,6 +183,7 @@ struct change_t { rtx object; int old_code; + int old_len; bool unshare; rtx *loc; rtx old; @@ -194,8 +195,10 @@ static int changes_allocated; static int num_changes = 0; /* Validate a proposed change to OBJECT. LOC is the location in the rtl - at which NEW_RTX will be placed. If OBJECT is zero, no validation is done, - the change is simply made. + at which NEW_RTX will be placed. If NEW_LEN is >= 0, XVECLEN (NEW_RTX, 0) + will also be changed to NEW_LEN, which is no greater than the current + XVECLEN. If OBJECT is zero, no validation is done, the change is + simply made. Two types of objects are supported: If OBJECT is a MEM, memory_address_p will be called with the address and mode as parameters. If OBJECT is @@ -212,14 +215,25 @@ static int num_changes = 0; Otherwise, perform the change and return 1. */ static bool -validate_change_1 (rtx object, rtx *loc, rtx new_rtx, bool in_group, bool unshare) +validate_change_1 (rtx object, rtx *loc, rtx new_rtx, bool in_group, + bool unshare, int new_len = -1) { rtx old = *loc; - if (old == new_rtx || rtx_equal_p (old, new_rtx)) + /* Single-element parallels aren't valid and won't match anything. + Replace them with the single element. */ + if (new_len == 1 && GET_CODE (new_rtx) == PARALLEL) + { + new_rtx = XVECEXP (new_rtx, 0, 0); + new_len = -1; + } + + if ((old == new_rtx || rtx_equal_p (old, new_rtx)) + && (new_len < 0 || XVECLEN (new_rtx, 0) == new_len)) return 1; - gcc_assert (in_group != 0 || num_changes == 0); + gcc_assert ((in_group != 0 || num_changes == 0) + && (new_len < 0 || new_rtx == *loc)); *loc = new_rtx; @@ -239,8 +253,12 @@ validate_change_1 (rtx object, rtx *loc, rtx new_rtx, bool in_group, bool unshar changes[num_changes].object = object; changes[num_changes].loc = loc; changes[num_changes].old = old; + changes[num_changes].old_len = (new_len >= 0 ? XVECLEN (new_rtx, 0) : -1); changes[num_changes].unshare = unshare; + if (new_len >= 0) + XVECLEN (new_rtx, 0) = new_len; + if (object && !MEM_P (object)) { /* Set INSN_CODE to force rerecognition of insn. Save old code in @@ -278,6 +296,14 @@ validate_unshare_change (rtx object, rtx *loc, rtx new_rtx, bool in_group) return validate_change_1 (object, loc, new_rtx, in_group, true); } +/* Change XVECLEN (*LOC, 0) to NEW_LEN. OBJECT, IN_GROUP and the return + value are as for validate_change_1. */ + +bool +validate_change_xveclen (rtx object, rtx *loc, int new_len, bool in_group) +{ + return validate_change_1 (object, loc, *loc, in_group, false, new_len); +} /* Keep X canonicalized if some changes have made it non-canonical; only modifies the operands of X, not (for example) its code. Simplifications @@ -541,7 +567,10 @@ cancel_changes (int num) they were made. */ for (i = num_changes - 1; i >= num; i--) { - *changes[i].loc = changes[i].old; + if (changes[i].old_len >= 0) + XVECLEN (*changes[i].loc, 0) = changes[i].old_len; + else + *changes[i].loc = changes[i].old; if (changes[i].object && !MEM_P (changes[i].object)) INSN_CODE (changes[i].object) = changes[i].old_code; } diff --git a/gcc/recog.h b/gcc/recog.h index d87456c257f..e152e2bb591 100644 --- a/gcc/recog.h +++ b/gcc/recog.h @@ -88,6 +88,7 @@ extern int check_asm_operands (rtx); extern int asm_operand_ok (rtx, const char *, const char **); extern bool validate_change (rtx, rtx *, rtx, bool); extern bool validate_unshare_change (rtx, rtx *, rtx, bool); +extern bool validate_change_xveclen (rtx, rtx *, int, bool); extern bool canonicalize_change_group (rtx_insn *insn, rtx x); extern int insn_invalid_p (rtx_insn *, bool); extern int verify_changes (int); -- 2.17.1