From patchwork Sun Sep 30 15:51:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Jansa X-Patchwork-Id: 29586 Received: (qmail 41982 invoked by alias); 30 Sep 2018 15:51:42 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 41972 invoked by uid 89); 30 Sep 2018 15:51:42 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.4 required=5.0 tests=AWL, BAYES_00, FREEMAIL_FROM, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=HX-Google-Smtp-Source:ACcGV63D X-HELO: mail-wr1-f44.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=uqi9x4YunSp2+PZ9sbe/XIGl5rzLSBkhcH6jEDI/cDk=; b=kaKstt6XN5k1M4jWoAad/z4AgeXHixtPI1MJ2a/YQF0AN3K3+EzNy5Ba30aLoqWvBt +owUoU+VirChaH6ksIX8+vmRcJJwvOp5k0Q81kchH3meC3bbNkgQAqjXdDQXNPbGlnTx 7D+vDQOpGZGddImhz4kPdexVse4xbzrATMmgHTv5C0ZEP27hreC5xZhJoMYvu8pQflMO jRcN3+knufZVIXEJZ++TscHb+dW+uZb2Rso7meF74uLhcJWUDNOWWZtz9uDnajFq0lw8 OtIIS5GGAwpP/6wgZfTUhyU19C/UJK5R42dJbaEVJXlCUBenCth1kuMA53pjE9+fVuI1 TjIQ== Return-Path: From: Martin Jansa To: libc-alpha@sourceware.org Cc: Martin Jansa Subject: [PATCHv3] sysdeps/ieee754: prevent maybe-uninitialized errors with -O [BZ #19444] Date: Sun, 30 Sep 2018 15:51:34 +0000 Message-Id: <20180930155134.32524-1-Martin.Jansa@gmail.com> In-Reply-To: <20180930135031.GE1449@jam> References: <20180930135031.GE1449@jam> With -O included in CFLAGS it fails to build with: ../sysdeps/ieee754/ldbl-96/e_jnl.c: In function '__ieee754_jnl': ../sysdeps/ieee754/ldbl-96/e_jnl.c:146:20: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized] b = invsqrtpi * temp / sqrtl (x); ~~~~~~~~~~^~~~~~ ../sysdeps/ieee754/ldbl-96/e_jnl.c: In function '__ieee754_ynl': ../sysdeps/ieee754/ldbl-96/e_jnl.c:375:16: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized] b = invsqrtpi * temp / sqrtl (x); ~~~~~~~~~~^~~~~~ ../sysdeps/ieee754/dbl-64/e_jn.c: In function '__ieee754_jn': ../sysdeps/ieee754/dbl-64/e_jn.c:113:20: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized] b = invsqrtpi * temp / sqrt (x); ~~~~~~~~~~^~~~~~ ../sysdeps/ieee754/dbl-64/e_jn.c: In function '__ieee754_yn': ../sysdeps/ieee754/dbl-64/e_jn.c:320:16: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized] b = invsqrtpi * temp / sqrt (x); ~~~~~~~~~~^~~~~~ Build tested with Yocto for ARM, AARCH64, X86, X86_64, PPC, MIPS, MIPS64 with -O, -O1, -Os. For soft-fp ARM it needs one more fix for -O1: https://sourceware.org/ml/libc-alpha/2018-09/msg00300.html For AARCH64 it needs one more fix in locale for -Os. [BZ #23716] * sysdeps/ieee754/dbl-96/e_jnl.c: Fix build with -O * sysdeps/ieee754/ldbl-96/e_jnl.c: Likewise. * sysdeps/ieee754/ldbl-128/e_jnl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/e_jnl.c: Likewise. Signed-off-by: Martin Jansa --- ChangeLog | 7 +++++++ sysdeps/ieee754/dbl-64/e_jn.c | 21 +++++++++++++++++++++ sysdeps/ieee754/ldbl-128/e_jnl.c | 21 +++++++++++++++++++++ sysdeps/ieee754/ldbl-128ibm/e_jnl.c | 21 +++++++++++++++++++++ sysdeps/ieee754/ldbl-96/e_jnl.c | 21 +++++++++++++++++++++ 5 files changed, 91 insertions(+) diff --git a/ChangeLog b/ChangeLog index 07760299e6..4bafeefda5 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2018-09-29 Martin Jansa + Partial fix for [BZ #23716] + * sysdeps/ieee754/dbl-96/e_jnl.c: Fix build with -O + * sysdeps/ieee754/ldbl-96/e_jnl.c: Likewise. + * sysdeps/ieee754/ldbl-128/e_jnl.c: Likewise. + * sysdeps/ieee754/ldbl-128ibm/e_jnl.c: Likewise. + 2018-09-28 Joseph Myers * math/fromfp.h: Do not include . diff --git a/sysdeps/ieee754/dbl-64/e_jn.c b/sysdeps/ieee754/dbl-64/e_jn.c index aff06ead16..2d8bafbcce 100644 --- a/sysdeps/ieee754/dbl-64/e_jn.c +++ b/sysdeps/ieee754/dbl-64/e_jn.c @@ -43,6 +43,7 @@ #include #include #include +#include static const double invsqrtpi = 5.64189583547756279280e-01, /* 0x3FE20DD7, 0x50429B6D */ @@ -110,7 +111,17 @@ __ieee754_jn (int n, double x) case 2: temp = -c - s; break; case 3: temp = c - s; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrt (x); + DIAG_POP_NEEDS_COMMENT; } else { @@ -317,7 +328,17 @@ __ieee754_yn (int n, double x) case 2: temp = -s + c; break; case 3: temp = s + c; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrt (x); + DIAG_POP_NEEDS_COMMENT; } else { diff --git a/sysdeps/ieee754/ldbl-128/e_jnl.c b/sysdeps/ieee754/ldbl-128/e_jnl.c index 7610d18c67..776da664dd 100644 --- a/sysdeps/ieee754/ldbl-128/e_jnl.c +++ b/sysdeps/ieee754/ldbl-128/e_jnl.c @@ -62,6 +62,7 @@ #include #include #include +#include static const _Float128 invsqrtpi = L(5.6418958354775628694807945156077258584405E-1), @@ -151,7 +152,17 @@ __ieee754_jnl (int n, _Float128 x) temp = c - s; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrtl (x); + DIAG_POP_NEEDS_COMMENT; } else { @@ -387,7 +398,17 @@ __ieee754_ynl (int n, _Float128 x) temp = s + c; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrtl (x); + DIAG_POP_NEEDS_COMMENT; } else { diff --git a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c index 50b4558e74..fcc2e2fae6 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c @@ -62,6 +62,7 @@ #include #include #include +#include static const long double invsqrtpi = 5.6418958354775628694807945156077258584405E-1L, @@ -151,7 +152,17 @@ __ieee754_jnl (int n, long double x) temp = c - s; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrtl (x); + DIAG_POP_NEEDS_COMMENT; } else { @@ -387,7 +398,17 @@ __ieee754_ynl (int n, long double x) temp = s + c; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrtl (x); + DIAG_POP_NEEDS_COMMENT; } else { diff --git a/sysdeps/ieee754/ldbl-96/e_jnl.c b/sysdeps/ieee754/ldbl-96/e_jnl.c index 855190841b..650ff19539 100644 --- a/sysdeps/ieee754/ldbl-96/e_jnl.c +++ b/sysdeps/ieee754/ldbl-96/e_jnl.c @@ -62,6 +62,7 @@ #include #include #include +#include static const long double invsqrtpi = 5.64189583547756286948079e-1L, two = 2.0e0L, one = 1.0e0L; @@ -144,7 +145,17 @@ __ieee754_jnl (int n, long double x) temp = c - s; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrtl (x); + DIAG_POP_NEEDS_COMMENT; } else { @@ -373,7 +384,17 @@ __ieee754_ynl (int n, long double x) temp = s + c; break; } + /* With GCC 8 (and older) when compiling with -O the compiler + warns that the variable 'temp', may be used uninitialized. + The switch above covers all possible values of n & 3 + but GCC without VRP enabled isn't able to figure out the + range of possible values is [0,3] as explained in: + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 + so it's false possitive with -O1 and lower. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); b = invsqrtpi * temp / sqrtl (x); + DIAG_POP_NEEDS_COMMENT; } else {