From patchwork Tue May 24 17:43:19 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Myers X-Patchwork-Id: 625754 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rDjSY2wpTz9sds for ; Wed, 25 May 2016 03:43:40 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b=g9j+QFRa; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:subject:message-id:mime-version :content-type; q=dns; s=default; b=ysU4a/8t/IO4FUi3qO9qknecjqM3Q 7ASDKs17Ink3XSlmFfq5zCOzjRzXEqLoKoCK+4Om4CIAhS/Vo5tgpRvJ/+wfWQA2 nILQe5IpWDB8uhGkY1SgN39Xae60sK87UilmTsi/PF0QAChgE6ZfrhOXaYNzLKHY iMsV3al2zlzYws= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:subject:message-id:mime-version :content-type; s=default; bh=N3rxfhgXZm0Tjb6WpqZMPnBD9lg=; b=g9j +QFRak0TtTI8czKRghkycJsZFzwabVfRgMQoIFozdDbX/8WDYPiVbwxvzy4jzh4h ICyCJvgtzhHRYb98TTDd5WTLLd7ym9GraQ8DROjymm5NMAA5469yFhFhQINBHfvm viBcE5BtQsd/lX4TmZ+HRKTes0z9KciFkigrIPOU= Received: (qmail 18668 invoked by alias); 24 May 2016 17:43:35 -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 18618 invoked by uid 89); 24 May 2016 17:43:34 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.6 required=5.0 tests=AWL, BAYES_50, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=NaN, 17, 6, 1511, 2215 X-HELO: relay1.mentorg.com Date: Tue, 24 May 2016 17:43:19 +0000 From: Joseph Myers To: Subject: Do not raise "inexact" from generic ceil (bug 15479) Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 C99 and C11 allow but do not require ceil, floor, round and trunc to raise the "inexact" exception for noninteger arguments. TS 18661-1 requires that this exception not be raised by these functions. This aligns them with general IEEE semantics, where "inexact" is only raised if the final step of rounding the infinite-precision result to the result type is inexact; for these functions, the infinite-precision integer result is always representable in the result type, so "inexact" should never be raised. The generic implementations of ceil, floor and round functions contain code to force "inexact" to be raised. This patch removes it for ceil functions to align them with TS 18661-1 in this regard. Note that some architecture-specific versions may still raise "inexact", so the tests are not updated and the bug is not yet fixed. Tested for x86_64, x86 and mips64. 2016-05-24 Joseph Myers [BZ #15479] * sysdeps/ieee754/dbl-64/s_ceil.c: Do not mention "inexact" exception in comment. (huge): Remove variable. (__ceil): Do not force "inexact" exception. * sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c: Do not mention "inexact" exception in comment. (huge): Remove variable. (__ceil): Do not force "inexact" exception. * sysdeps/ieee754/flt-32/s_ceilf.c (huge): Remove variable. (__ceilf): Do not force "inexact" exception. * sysdeps/ieee754/ldbl-128/s_ceill.c: Do not mention "inexact" exception in comment. (huge): Remove variable. (__ceill): Do not force "inexact" exception. diff --git a/sysdeps/ieee754/dbl-64/s_ceil.c b/sysdeps/ieee754/dbl-64/s_ceil.c index b2154b4..c291c26 100644 --- a/sysdeps/ieee754/dbl-64/s_ceil.c +++ b/sysdeps/ieee754/dbl-64/s_ceil.c @@ -15,15 +15,11 @@ * Return x rounded toward -inf to integral value * Method: * Bit twiddling. - * Exception: - * Inexact flag raised if x not equal to ceil(x). */ #include #include -static const double huge = 1.0e300; - double __ceil (double x) { @@ -33,9 +29,8 @@ __ceil (double x) j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; if (j0 < 20) { - if (j0 < 0) /* raise inexact if x != 0 */ + if (j0 < 0) { - math_force_eval (huge + x); /* return 0*sign(x) if |x|<1 */ if (i0 < 0) { @@ -51,7 +46,6 @@ __ceil (double x) i = (0x000fffff) >> j0; if (((i0 & i) | i1) == 0) return x; /* x is integral */ - math_force_eval (huge + x); /* raise inexact flag */ if (i0 > 0) i0 += (0x00100000) >> j0; i0 &= (~i); i1 = 0; @@ -69,7 +63,6 @@ __ceil (double x) i = ((u_int32_t) (0xffffffff)) >> (j0 - 20); if ((i1 & i) == 0) return x; /* x is integral */ - math_force_eval (huge + x); /* raise inexact flag */ if (i0 > 0) { if (j0 == 20) diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c index c687525..faaaf90 100644 --- a/sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c +++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c @@ -15,15 +15,11 @@ * Return x rounded toward -inf to integral value * Method: * Bit twiddling. - * Exception: - * Inexact flag raised if x not equal to ceil(x). */ #include #include -static const double huge = 1.0e300; - double __ceil(double x) { @@ -32,14 +28,13 @@ __ceil(double x) EXTRACT_WORDS64(i0,x); j0 = ((i0>>52)&0x7ff)-0x3ff; if(j0<=51) { - if(j0<0) { /* raise inexact if x != 0 */ - math_force_eval(huge+x);/* return 0*sign(x) if |x|<1 */ + if(j0<0) { + /* return 0*sign(x) if |x|<1 */ if(i0<0) {i0=INT64_C(0x8000000000000000);} else if(i0!=0) { i0=INT64_C(0x3ff0000000000000);} } else { i = INT64_C(0x000fffffffffffff)>>j0; if((i0&i)==0) return x; /* x is integral */ - math_force_eval(huge+x); /* raise inexact flag */ if(i0>0) i0 += UINT64_C(0x0010000000000000)>>j0; i0 &= (~i); } diff --git a/sysdeps/ieee754/flt-32/s_ceilf.c b/sysdeps/ieee754/flt-32/s_ceilf.c index 37659ea..bff26c3 100644 --- a/sysdeps/ieee754/flt-32/s_ceilf.c +++ b/sysdeps/ieee754/flt-32/s_ceilf.c @@ -17,8 +17,6 @@ #include -static const float huge = 1.0e30; - float __ceilf(float x) { @@ -28,14 +26,13 @@ __ceilf(float x) GET_FLOAT_WORD(i0,x); j0 = ((i0>>23)&0xff)-0x7f; if(j0<23) { - if(j0<0) { /* raise inexact if x != 0 */ - math_force_eval(huge+x);/* return 0*sign(x) if |x|<1 */ + if(j0<0) { + /* return 0*sign(x) if |x|<1 */ if(i0<0) {i0=0x80000000;} else if(i0!=0) { i0=0x3f800000;} } else { i = (0x007fffff)>>j0; if((i0&i)==0) return x; /* x is integral */ - math_force_eval(huge+x); /* raise inexact flag */ if(i0>0) i0 += (0x00800000)>>j0; i0 &= (~i); } diff --git a/sysdeps/ieee754/ldbl-128/s_ceill.c b/sysdeps/ieee754/ldbl-128/s_ceill.c index 9f6bc4c..6b73673 100644 --- a/sysdeps/ieee754/ldbl-128/s_ceill.c +++ b/sysdeps/ieee754/ldbl-128/s_ceill.c @@ -22,15 +22,11 @@ static char rcsid[] = "$NetBSD: $"; * Return x rounded toward -inf to integral value * Method: * Bit twiddling. - * Exception: - * Inexact flag raised if x not equal to ceil(x). */ #include #include -static const long double huge = 1.0e4930L; - long double __ceill(long double x) { int64_t i0,i1,j0; @@ -38,18 +34,15 @@ long double __ceill(long double x) GET_LDOUBLE_WORDS64(i0,i1,x); j0 = ((i0>>48)&0x7fff)-0x3fff; if(j0<48) { - if(j0<0) { /* raise inexact if x != 0 */ - if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */ - if(i0<0) {i0=0x8000000000000000ULL;i1=0;} - else if((i0|i1)!=0) { i0=0x3fff000000000000ULL;i1=0;} - } + if(j0<0) { + /* return 0*sign(x) if |x|<1 */ + if(i0<0) {i0=0x8000000000000000ULL;i1=0;} + else if((i0|i1)!=0) { i0=0x3fff000000000000ULL;i1=0;} } else { i = (0x0000ffffffffffffULL)>>j0; if(((i0&i)|i1)==0) return x; /* x is integral */ - if(huge+x>0.0) { /* raise inexact flag */ - if(i0>0) i0 += (0x0001000000000000LL)>>j0; - i0 &= (~i); i1=0; - } + if(i0>0) i0 += (0x0001000000000000LL)>>j0; + i0 &= (~i); i1=0; } } else if (j0>111) { if(j0==0x4000) return x+x; /* inf or NaN */ @@ -57,17 +50,15 @@ long double __ceill(long double x) } else { i = -1ULL>>(j0-48); if((i1&i)==0) return x; /* x is integral */ - if(huge+x>0.0) { /* raise inexact flag */ - if(i0>0) { - if(j0==48) i0+=1; - else { - j = i1+(1LL<<(112-j0)); - if(j0) { + if(j0==48) i0+=1; + else { + j = i1+(1LL<<(112-j0)); + if(j