From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 48743 invoked by alias); 27 Nov 2017 13:39:39 -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 48721 invoked by uid 89); 27 Nov 2017 13:39:37 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-10.4 required=5.0 tests=BAYES_00,GIT_PATCH_2,GIT_PATCH_3,KAM_ASCII_DIVIDERS,KAM_NUMSUBJECT,KB_WAM_FROM_NAME_SINGLEWORD,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=costly X-HELO: mx2.suse.de Received: from mx2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 27 Nov 2017 13:39:32 +0000 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 56BAEAAAD for ; Mon, 27 Nov 2017 13:39:29 +0000 (UTC) Date: Mon, 27 Nov 2017 14:34:00 -0000 From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] Fix PR80776 Message-ID: User-Agent: Alpine 2.20 (LSU 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-SW-Source: 2017-11/txt/msg02299.txt.bz2 The following avoids -Wformat-overflow false positives by teaching EVRP the trick about __builtin_unreachable () "other" edges and attaching range info to SSA names. EVRP does a better job in keeping ranges for every SSA name from conditional info (VRP "optimizes" its costly ASSERT_EXPR insertion process). Bootstrapped on x86_64-unknown-linux-gnu, testing in progress. This will also fix the testcase from PR83072 but it doesn't really fix all cases I want to fix with a fix for it. OTOH it might be this is enough for stage3. Richard. 2017-11-27 Richard Biener PR tree-optimization/80776 * gimple-ssa-evrp-analyze.h (evrp_range_analyzer::set_ssa_range_info): Declare. * gimple-ssa-evrp-analyze.c (evrp_range_analyzer::set_ssa_range_info): New function. (evrp_range_analyzer::record_ranges_from_incoming_edges): If the incoming edge is an effective fallthru because the other edge only reaches a __builtin_unreachable () then record ranges derived from the controlling condition in SSA info. (evrp_range_analyzer::record_ranges_from_phis): Use set_ssa_range_info. (evrp_range_analyzer::record_ranges_from_stmt): Likewise. * gcc.dg/pr80776-1.c: New testcase. * gcc.dg/pr80776-2.c: Likewise. Index: gcc/gimple-ssa-evrp-analyze.c =================================================================== --- gcc/gimple-ssa-evrp-analyze.c (revision 255163) +++ gcc/gimple-ssa-evrp-analyze.c (working copy) @@ -91,6 +91,31 @@ evrp_range_analyzer::try_find_new_range return NULL; } +/* For LHS record VR in the SSA info. */ +void +evrp_range_analyzer::set_ssa_range_info (tree lhs, value_range *vr) +{ + /* Set the SSA with the value range. */ + if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))) + { + if ((vr->type == VR_RANGE + || vr->type == VR_ANTI_RANGE) + && (TREE_CODE (vr->min) == INTEGER_CST) + && (TREE_CODE (vr->max) == INTEGER_CST)) + set_range_info (lhs, vr->type, + wi::to_wide (vr->min), + wi::to_wide (vr->max)); + } + else if (POINTER_TYPE_P (TREE_TYPE (lhs)) + && ((vr->type == VR_RANGE + && range_includes_zero_p (vr->min, + vr->max) == 0) + || (vr->type == VR_ANTI_RANGE + && range_includes_zero_p (vr->min, + vr->max) == 1))) + set_ptr_nonnull (lhs); +} + void evrp_range_analyzer::record_ranges_from_incoming_edge (basic_block bb) { @@ -134,10 +159,19 @@ evrp_range_analyzer::record_ranges_from_ if (vr) vrs.safe_push (std::make_pair (asserts[i].name, vr)); } + + /* If pred_e is really a fallthru we can record value ranges + in SSA names as well. */ + bool is_fallthru = assert_unreachable_fallthru_edge_p (pred_e); + /* Push updated ranges only after finding all of them to avoid ordering issues that can lead to worse ranges. */ for (unsigned i = 0; i < vrs.length (); ++i) - push_value_range (vrs[i].first, vrs[i].second); + { + push_value_range (vrs[i].first, vrs[i].second); + if (is_fallthru) + set_ssa_range_info (vrs[i].first, vrs[i].second); + } } } } @@ -185,24 +219,7 @@ evrp_range_analyzer::record_ranges_from_ vr_values->update_value_range (lhs, &vr_result); /* Set the SSA with the value range. */ - if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))) - { - if ((vr_result.type == VR_RANGE - || vr_result.type == VR_ANTI_RANGE) - && (TREE_CODE (vr_result.min) == INTEGER_CST) - && (TREE_CODE (vr_result.max) == INTEGER_CST)) - set_range_info (lhs, vr_result.type, - wi::to_wide (vr_result.min), - wi::to_wide (vr_result.max)); - } - else if (POINTER_TYPE_P (TREE_TYPE (lhs)) - && ((vr_result.type == VR_RANGE - && range_includes_zero_p (vr_result.min, - vr_result.max) == 0) - || (vr_result.type == VR_ANTI_RANGE - && range_includes_zero_p (vr_result.min, - vr_result.max) == 1))) - set_ptr_nonnull (lhs); + set_ssa_range_info (lhs, &vr_result); } } @@ -224,21 +241,7 @@ evrp_range_analyzer::record_ranges_from_ vr_values->update_value_range (output, &vr); /* Set the SSA with the value range. */ - if (INTEGRAL_TYPE_P (TREE_TYPE (output))) - { - if ((vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE) - && (TREE_CODE (vr.min) == INTEGER_CST) - && (TREE_CODE (vr.max) == INTEGER_CST)) - set_range_info (output, vr.type, - wi::to_wide (vr.min), - wi::to_wide (vr.max)); - } - else if (POINTER_TYPE_P (TREE_TYPE (output)) - && ((vr.type == VR_RANGE - && range_includes_zero_p (vr.min, vr.max) == 0) - || (vr.type == VR_ANTI_RANGE - && range_includes_zero_p (vr.min, vr.max) == 1))) - set_ptr_nonnull (output); + set_ssa_range_info (output, &vr); } else vr_values->set_defs_to_varying (stmt); Index: gcc/gimple-ssa-evrp-analyze.h =================================================================== --- gcc/gimple-ssa-evrp-analyze.h (revision 255163) +++ gcc/gimple-ssa-evrp-analyze.h (working copy) @@ -68,6 +68,7 @@ class evrp_range_analyzer value_range *try_find_new_range (tree, tree op, tree_code code, tree limit); void record_ranges_from_incoming_edge (basic_block); void record_ranges_from_phis (basic_block); + void set_ssa_range_info (tree, value_range *); /* STACK holds the old VR. */ auto_vec > stack; Index: gcc/testsuite/gcc.dg/pr80776-1.c =================================================================== --- gcc/testsuite/gcc.dg/pr80776-1.c (nonexistent) +++ gcc/testsuite/gcc.dg/pr80776-1.c (working copy) @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -Wformat-overflow" } */ + +extern __inline __attribute__ ((__always_inline__)) __attribute__ ((__gnu_inline__)) __attribute__ ((__artificial__)) int +__attribute__ ((__nothrow__ , __leaf__)) sprintf (char *__restrict __s, const char *__restrict __fmt, ...) +{ + return __builtin___sprintf_chk (__s, 2 - 1, + __builtin_object_size (__s, 2 > 1), __fmt, __builtin_va_arg_pack ()); +} +char number[sizeof "999999"]; +int somerandom (void); +void +Foo (void) +{ + int i = somerandom (); + if (! (0 <= i)) + __builtin_unreachable (); + if (! (0 <= i && i <= 999999)) + __builtin_unreachable (); + sprintf (number, "%d", i); /* { dg-bogus "writing" } */ +} Index: gcc/testsuite/gcc.dg/pr80776-2.c =================================================================== --- gcc/testsuite/gcc.dg/pr80776-2.c (nonexistent) +++ gcc/testsuite/gcc.dg/pr80776-2.c (working copy) @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -Wformat-overflow" } */ + +extern int sprintf (char *restrict, const char *restrict, ...) + __attribute__ ((__nothrow__)); + extern int foo (void); + +int +Fgenerate_new_buffer_name (void) +{ + char number[2]; + int i = foo (); + if (i < 0) + __builtin_unreachable (); + if (i >= 2) + __builtin_unreachable (); + return sprintf (number, "%d", i); /* { dg-bogus "writing" } */ +}