From patchwork Wed Oct 19 22:59:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Myers X-Patchwork-Id: 16680 Received: (qmail 58068 invoked by alias); 19 Oct 2016 22:59:45 -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 58047 invoked by uid 89); 19 Oct 2016 22:59:44 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.5 required=5.0 tests=AWL, BAYES_50, RCVD_IN_DNSWL_NONE, SPF_PASS, URIBL_RED autolearn=ham version=3.3.2 spammy=3014, blr, 3016, fmr X-HELO: relay1.mentorg.com Date: Wed, 19 Oct 2016 22:59:25 +0000 From: Joseph Myers To: Subject: Stop powerpc copysignl raising "invalid" for sNaN argument (bug 20718) [committed] Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 X-ClientProxiedBy: svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) The powerpc (hard-float) implementations of copysignl, both 32-bit and 64-bit, raise spurious "invalid" exceptions when the first argument is a signaling NaN. copysign functions should never raise exceptions even for signaling NaNs. The problem is the use of an fcmpu instruction to test the sign of the high part of the long double argument. This patch fixes the functions to use fsel instead (as used for fabsl following my fixes for a similar bug there), or to examine the integer representation for older 32-bit processors without fsel. Tested for powerpc64 and powerpc32 (configurations with and without fsel used). Committed. 2016-10-19 Joseph Myers [BZ #20718] * sysdeps/powerpc/powerpc32/fpu/s_copysignl.S (__copysignl): Do not use floating-point comparisons to test sign. * sysdeps/powerpc/powerpc64/fpu/s_copysignl.S (__copysignl): Likewise. diff --git a/sysdeps/powerpc/powerpc32/fpu/s_copysignl.S b/sysdeps/powerpc/powerpc32/fpu/s_copysignl.S index aed783a..1eec847 100644 --- a/sysdeps/powerpc/powerpc32/fpu/s_copysignl.S +++ b/sysdeps/powerpc/powerpc32/fpu/s_copysignl.S @@ -24,22 +24,39 @@ ENTRY(__copysignl) /* long double [f1,f2] copysign (long double [f1,f2] x, long double [f3,f4] y); copysign(x,y) returns a value with the magnitude of x and with the sign bit of y. */ +#ifdef _ARCH_PPCGR + /* fsel available. */ stwu r1,-16(r1) cfi_adjust_cfa_offset (16) stfd fp3,8(r1) fmr fp0,fp1 fabs fp1,fp1 - fcmpu cr7,fp0,fp1 lwz r3,8+HIWORD(r1) cmpwi cr6,r3,0 addi r1,r1,16 cfi_adjust_cfa_offset (-16) - beq cr7,L(0) + fneg fp3,fp2 + fsel fp2,fp0,fp2,fp3 + bgelr cr6 + fneg fp1,fp1 fneg fp2,fp2 -L(0): bgelr cr6 + blr +#else + stwu r1,-32(r1) + cfi_adjust_cfa_offset (32) + stfd fp3,8(r1) + stfd fp1,16(r1) + lwz r3,8+HIWORD(r1) + lwz r4,16+HIWORD(r1) + xor r3,r3,r4 + cmpwi cr6,r3,0 + addi r1,r1,32 + cfi_adjust_cfa_offset (-32) + bgelr cr6 fneg fp1,fp1 fneg fp2,fp2 blr +#endif END (__copysignl) #if IS_IN (libm) diff --git a/sysdeps/powerpc/powerpc64/fpu/s_copysignl.S b/sysdeps/powerpc/powerpc64/fpu/s_copysignl.S index 1e1b9d4..548076d 100644 --- a/sysdeps/powerpc/powerpc64/fpu/s_copysignl.S +++ b/sysdeps/powerpc/powerpc64/fpu/s_copysignl.S @@ -30,16 +30,14 @@ ENTRY(__copysignl) blt L(0) fmr fp0,fp1 fabs fp1,fp1 - fcmpu cr1,fp0,fp1 - beqlr cr1 - fneg fp2,fp2 + fneg fp3,fp2 + fsel fp2,fp0,fp2,fp3 blr L(0): fmr fp0,fp1 fnabs fp1,fp1 - fcmpu cr1,fp0,fp1 - beqlr cr1 - fneg fp2,fp2 + fneg fp3,fp2 + fsel fp2,fp0,fp3,fp2 blr END (__copysignl)