From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 34508 invoked by alias); 23 Oct 2017 17:16:16 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 34489 invoked by uid 89); 23 Oct 2017 17:16:16 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-11.3 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_2,GIT_PATCH_3,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mail-wr0-f174.google.com Received: from mail-wr0-f174.google.com (HELO mail-wr0-f174.google.com) (209.85.128.174) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 23 Oct 2017 17:16:14 +0000 Received: by mail-wr0-f174.google.com with SMTP id g90so18135616wrd.6 for ; Mon, 23 Oct 2017 10:16:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:mail-followup-to:subject:references:date :in-reply-to:message-id:user-agent:mime-version; bh=/R9p0EPAVZRutMGavwECPCAzD0LKssBG4vC76XLLjH4=; b=sDne4wyi4wNXq/H1baS6/jCMzTcNYt7NaMo33al/+ekF7el5V5aW55R+l7ZPSM919B bJ2kobcNcsTSCE/FEOYhp4bdPpn/y0aAXVIuQ2eYcLkymIyprGWoOI7QEr7xHumC5UR0 KChR5anay2n80h24iI17CHLVlFV7JUEP3CMrb5bnX2nzJZfsRoeexE0joK3a0q2IsYtm PcpmBZusyy0B4YbkOzJrIgzr5uT8ZRjqg3ErX7tVfu7aThWp6laj/albOszvVR0D0Qc1 67HXWm7JyleHh+7suzDBf/xElF81/kvrhqN0+EOLH+1BQUxE/XQFoFrIfWYPSdCOXhQS OfQA== X-Gm-Message-State: AMCzsaUBKbrKnkxs8O/S+c03fLAMLFML2VxA/vUqPwAcbc0TvRTC0+VS foYZihkt7WHRCW/2l/iX3UEKknMQnWE= X-Google-Smtp-Source: ABhQp+Qo+4nkKy8OjreMoKviy443rBI/bxlTAhFNXot0EjR6E7cF0WoUWVzRVWSRgkf40WuGNc2ttw== X-Received: by 10.223.173.104 with SMTP id p95mr11049434wrc.209.1508778972260; Mon, 23 Oct 2017 10:16:12 -0700 (PDT) Received: from localhost ([2.26.27.199]) by smtp.gmail.com with ESMTPSA id v78sm3091602wmv.48.2017.10.23.10.16.11 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 23 Oct 2017 10:16:11 -0700 (PDT) From: Richard Sandiford To: gcc-patches@gcc.gnu.org Mail-Followup-To: gcc-patches@gcc.gnu.org, richard.sandiford@linaro.org Subject: [038/nnn] poly_int: fold_comparison References: <871sltvm7r.fsf@linaro.org> Date: Mon, 23 Oct 2017 17:17:00 -0000 In-Reply-To: <871sltvm7r.fsf@linaro.org> (Richard Sandiford's message of "Mon, 23 Oct 2017 17:54:32 +0100") Message-ID: <87bmkxokdh.fsf@linaro.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-SW-Source: 2017-10/txt/msg01539.txt.bz2 This patch makes fold_comparison track polynomial offsets when folding address comparisons. 2017-10-23 Richard Sandiford Alan Hayward David Sherwood gcc/ * fold-const.c (fold_comparison): Track sizes and offsets as poly_int64s rather than HOST_WIDE_INTs when folding address comparisons. Index: gcc/fold-const.c =================================================================== --- gcc/fold-const.c 2017-10-23 17:18:43.843393046 +0100 +++ gcc/fold-const.c 2017-10-23 17:18:44.902299961 +0100 @@ -8522,7 +8522,7 @@ fold_comparison (location_t loc, enum tr || TREE_CODE (arg1) == POINTER_PLUS_EXPR)) { tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE; - HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0; + poly_int64 bitsize, bitpos0 = 0, bitpos1 = 0; machine_mode mode; int volatilep, reversep, unsignedp; bool indirect_base0 = false, indirect_base1 = false; @@ -8563,17 +8563,14 @@ fold_comparison (location_t loc, enum tr else offset0 = size_binop (PLUS_EXPR, offset0, TREE_OPERAND (arg0, 1)); - if (TREE_CODE (offset0) == INTEGER_CST) + if (poly_int_tree_p (offset0)) { - offset_int tem = wi::sext (wi::to_offset (offset0), - TYPE_PRECISION (sizetype)); + poly_offset_int tem = wi::sext (wi::to_poly_offset (offset0), + TYPE_PRECISION (sizetype)); tem <<= LOG2_BITS_PER_UNIT; tem += bitpos0; - if (wi::fits_shwi_p (tem)) - { - bitpos0 = tem.to_shwi (); - offset0 = NULL_TREE; - } + if (tem.to_shwi (&bitpos0)) + offset0 = NULL_TREE; } } @@ -8609,17 +8606,14 @@ fold_comparison (location_t loc, enum tr else offset1 = size_binop (PLUS_EXPR, offset1, TREE_OPERAND (arg1, 1)); - if (TREE_CODE (offset1) == INTEGER_CST) + if (poly_int_tree_p (offset1)) { - offset_int tem = wi::sext (wi::to_offset (offset1), - TYPE_PRECISION (sizetype)); + poly_offset_int tem = wi::sext (wi::to_poly_offset (offset1), + TYPE_PRECISION (sizetype)); tem <<= LOG2_BITS_PER_UNIT; tem += bitpos1; - if (wi::fits_shwi_p (tem)) - { - bitpos1 = tem.to_shwi (); - offset1 = NULL_TREE; - } + if (tem.to_shwi (&bitpos1)) + offset1 = NULL_TREE; } } @@ -8635,7 +8629,7 @@ fold_comparison (location_t loc, enum tr && operand_equal_p (offset0, offset1, 0))) { if (!equality_code - && bitpos0 != bitpos1 + && may_ne (bitpos0, bitpos1) && (pointer_may_wrap_p (base0, offset0, bitpos0) || pointer_may_wrap_p (base1, offset1, bitpos1))) fold_overflow_warning (("assuming pointer wraparound does not " @@ -8646,17 +8640,41 @@ fold_comparison (location_t loc, enum tr switch (code) { case EQ_EXPR: - return constant_boolean_node (bitpos0 == bitpos1, type); + if (must_eq (bitpos0, bitpos1)) + return boolean_true_node; + if (must_ne (bitpos0, bitpos1)) + return boolean_false_node; + break; case NE_EXPR: - return constant_boolean_node (bitpos0 != bitpos1, type); + if (must_ne (bitpos0, bitpos1)) + return boolean_true_node; + if (must_eq (bitpos0, bitpos1)) + return boolean_false_node; + break; case LT_EXPR: - return constant_boolean_node (bitpos0 < bitpos1, type); + if (must_lt (bitpos0, bitpos1)) + return boolean_true_node; + if (must_ge (bitpos0, bitpos1)) + return boolean_false_node; + break; case LE_EXPR: - return constant_boolean_node (bitpos0 <= bitpos1, type); + if (must_le (bitpos0, bitpos1)) + return boolean_true_node; + if (must_gt (bitpos0, bitpos1)) + return boolean_false_node; + break; case GE_EXPR: - return constant_boolean_node (bitpos0 >= bitpos1, type); + if (must_ge (bitpos0, bitpos1)) + return boolean_true_node; + if (must_lt (bitpos0, bitpos1)) + return boolean_false_node; + break; case GT_EXPR: - return constant_boolean_node (bitpos0 > bitpos1, type); + if (must_gt (bitpos0, bitpos1)) + return boolean_true_node; + if (must_le (bitpos0, bitpos1)) + return boolean_false_node; + break; default:; } } @@ -8667,7 +8685,7 @@ fold_comparison (location_t loc, enum tr because pointer arithmetic is restricted to retain within an object and overflow on pointer differences is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */ - else if (bitpos0 == bitpos1) + else if (must_eq (bitpos0, bitpos1)) { /* By converting to signed sizetype we cover middle-end pointer arithmetic which operates on unsigned pointer types of size @@ -8696,7 +8714,7 @@ fold_comparison (location_t loc, enum tr } /* For equal offsets we can simplify to a comparison of the base addresses. */ - else if (bitpos0 == bitpos1 + else if (must_eq (bitpos0, bitpos1) && (indirect_base0 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0) && (indirect_base1 @@ -8725,7 +8743,7 @@ fold_comparison (location_t loc, enum tr eliminated. When ptr is null, although the -> expression is strictly speaking invalid, GCC retains it as a matter of QoI. See PR c/44555. */ - && (offset0 == NULL_TREE && bitpos0 != 0)) + && (offset0 == NULL_TREE && known_nonzero (bitpos0))) || CONSTANT_CLASS_P (base0)) && indirect_base0 /* The caller guarantees that when one of the arguments is