From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 79871 invoked by alias); 25 May 2017 17:47:37 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 79787 invoked by uid 89); 25 May 2017 17:47:36 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 spammy=tn, jz, doubles, rz X-HELO: mx0a-001b2d01.pphosted.com Reply-To: pc@us.ibm.com To: libc-alpha@sourceware.org From: Paul Clarke Subject: [PATCH] powerpc: Add a POWER8-optimized version of powf() Date: Thu, 25 May 2017 17:47:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17052517-0056-0000-0000-00000370FA83 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007116; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00865536; UDB=6.00429783; IPR=6.00645312; BA=6.00005375; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015581; XFM=3.00000015; UTC=2017-05-25 17:47:32 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17052517-0057-0000-0000-000007A72F61 Message-Id: <8c7e16e8-d605-9552-89cc-c658dba81a6f@us.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-25_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=4 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1705250327 X-SW-Source: 2017-05/txt/msg00767.txt.bz2 This implementation is heavily based on sysdeps/ieee754/flt-32/e_powf.c. Most significant changes are code simplification and use of doubles for intermediate values. Also, some rearrangement to move early non-dependent code later, out of the faster paths. 2017-05-25 Paul A. Clarke * sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile [$(subdir) = math] (libm-sysdep_routines): Add e_powf-power8 and e_powf-ppc64. * sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-power8.c: New file. * sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-ppc64.c: Likewise. * sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf.c: Likewise. * sysdeps/powerpc/powerpc64/power8/fpu/e_powf.c: Likewise. --- sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile | 3 +- .../multiarch/{s_cosf-ppc64.c => e_powf-power8.c} | 12 +- .../powerpc64/fpu/multiarch/e_powf-ppc64.c} | 9 +- .../powerpc64/fpu/multiarch/{s_cosf.c => e_powf.c} | 16 +-- .../powerpc64/power8/fpu}/e_powf.c | 140 +++++++-------------- 5 files changed, 69 insertions(+), 111 deletions(-) copy sysdeps/powerpc/powerpc64/fpu/multiarch/{s_cosf-ppc64.c => e_powf-power8.c} (80%) copy sysdeps/{i386/symbol-hacks.h => powerpc/powerpc64/fpu/multiarch/e_powf-ppc64.c} (82%) copy sysdeps/powerpc/powerpc64/fpu/multiarch/{s_cosf.c => e_powf.c} (71%) copy sysdeps/{ieee754/flt-32 => powerpc/powerpc64/power8/fpu}/e_powf.c (69%) diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile index 317a988..dc7422e 100644 --- a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile +++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile @@ -27,7 +27,8 @@ libm-sysdep_routines += s_isnan-power7 s_isnan-power6x s_isnan-power6 \ s_llrint-power8 s_llround-power8 \ e_expf-power8 e_expf-ppc64 \ s_sinf-ppc64 s_sinf-power8 \ - s_cosf-ppc64 s_cosf-power8 + s_cosf-ppc64 s_cosf-power8 \ + e_powf-ppc64 e_powf-power8 CFLAGS-s_logbf-power7.c = -mcpu=power7 CFLAGS-s_logbl-power7.c = -mcpu=power7 diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_cosf-ppc64.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-power8.c similarity index 80% copy from sysdeps/powerpc/powerpc64/fpu/multiarch/s_cosf-ppc64.c copy to sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-power8.c index 635624c..5dfd969 100644 --- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_cosf-ppc64.c +++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-power8.c @@ -1,4 +1,4 @@ -/* cosf function. PowerPC64 default version. +/* __ieee754_powf() POWER8 version. Copyright (C) 2017 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -16,11 +16,9 @@ License along with the GNU C Library; if not, see . */ -#include +#undef strong_alias +#define strong_alias(a, b) -#undef weak_alias -#define weak_alias(a, b) +#define __ieee754_powf __ieee754_powf_power8 -#define __cosf __cosf_ppc64 - -#include +#include diff --git a/sysdeps/i386/symbol-hacks.h b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-ppc64.c similarity index 82% copy from sysdeps/i386/symbol-hacks.h copy to sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-ppc64.c index 36a13c8..43b466d 100644 --- a/sysdeps/i386/symbol-hacks.h +++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-ppc64.c @@ -1,4 +1,4 @@ -/* Hacks needed for symbol manipulation. i386 version. +/* __ieee_powf() PowerPC64 version. Copyright (C) 2017 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -16,6 +16,9 @@ License along with the GNU C Library; if not, see . */ -#include +#undef strong_alias +#define strong_alias(a, b) -#include_next "symbol-hacks.h" +#define __ieee754_powf __ieee754_powf_ppc64 + +#include diff --git a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_cosf.c b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf.c similarity index 71% copy from sysdeps/powerpc/powerpc64/fpu/multiarch/s_cosf.c copy to sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf.c index acf2a59..325d166 100644 --- a/sysdeps/powerpc/powerpc64/fpu/multiarch/s_cosf.c +++ b/sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf.c @@ -1,4 +1,4 @@ -/* Multiple versions of cosf. +/* Multiple versions of ieee754_powf. Copyright (C) 2017 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -17,15 +17,15 @@ . */ #include -#include +#include #include "init-arch.h" -extern __typeof (__cosf) __cosf_ppc64 attribute_hidden; -extern __typeof (__cosf) __cosf_power8 attribute_hidden; +extern __typeof (__ieee754_powf) __ieee754_powf_ppc64 attribute_hidden; +extern __typeof (__ieee754_powf) __ieee754_powf_power8 attribute_hidden; -libc_ifunc (__cosf, +libc_ifunc (__ieee754_powf, (hwcap2 & PPC_FEATURE2_ARCH_2_07) - ? __cosf_power8 - : __cosf_ppc64); + ? __ieee754_powf_power8 + : __ieee754_powf_ppc64); -weak_alias (__cosf, cosf) +strong_alias (__ieee754_powf, __powf_finite) diff --git a/sysdeps/ieee754/flt-32/e_powf.c b/sysdeps/powerpc/powerpc64/power8/fpu/e_powf.c similarity index 69% copy from sysdeps/ieee754/flt-32/e_powf.c copy to sysdeps/powerpc/powerpc64/power8/fpu/e_powf.c index 13b49de..628232a 100644 --- a/sysdeps/ieee754/flt-32/e_powf.c +++ b/sysdeps/powerpc/powerpc64/power8/fpu/e_powf.c @@ -4,7 +4,7 @@ /* * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * Copyright (C) 1993-2017 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this @@ -38,11 +38,9 @@ P2 = -2.7777778450e-03, /* 0xbb360b61 */ P3 = 6.6137559770e-05, /* 0x388ab355 */ P4 = -1.6533901999e-06, /* 0xb5ddea0e */ P5 = 4.1381369442e-08, /* 0x3331bb4c */ -lg2 = 6.9314718246e-01, /* 0x3f317218 */ lg2_h = 6.93145752e-01, /* 0x3f317200 */ lg2_l = 1.42860654e-06, /* 0x35bfbe8c */ ovt = 4.2995665694e-08, /* -(128-log2(ovfl+.5ulp)) */ -cp = 9.6179670095e-01, /* 0x3f76384f =2/(3ln2) */ cp_h = 0xf.64p-4, /* cp high 12 bits. */ cp_l = -0x7.b11e3p-16, /* 2/(3ln2) - cp_h. */ ivln2 = 1.4426950216e+00, /* 0x3fb8aa3b =1/ln2 */ @@ -52,14 +50,13 @@ ivln2_l = 7.0526075433e-06; /* 0x36eca570 =1/ln2 tail*/ float __ieee754_powf(float x, float y) { - float z,ax,z_h,z_l,p_h,p_l; - float y1,t1,t2,r,s,t,u,v,w; + float z, ax, s; + double d1, d2; int32_t i,j,k,yisint,n; - int32_t hx,hy,ix,iy,is; + int32_t hx,hy,ix,iy; - GET_FLOAT_WORD(hx,x); GET_FLOAT_WORD(hy,y); - ix = hx&0x7fffffff; iy = hy&0x7fffffff; + iy = hy&0x7fffffff; /* y==zero: x**0 = 1 */ if(iy==0 && !issignaling (x)) return one; @@ -68,26 +65,14 @@ __ieee754_powf(float x, float y) if(x == 1.0 && !issignaling (y)) return one; if(x == -1.0 && isinf(y)) return one; + GET_FLOAT_WORD(hx,x); + ix = hx&0x7fffffff; + /* +-NaN return x+y */ if(__builtin_expect(ix > 0x7f800000 || iy > 0x7f800000, 0)) return x+y; - /* determine if y is an odd int when x < 0 - * yisint = 0 ... y is not an integer - * yisint = 1 ... y is an odd int - * yisint = 2 ... y is an even int - */ - yisint = 0; - if(hx<0) { - if(iy>=0x4b800000) yisint = 2; /* even integer y */ - else if(iy>=0x3f800000) { - k = (iy>>23)-0x7f; /* exponent */ - j = iy>>(23-k); - if((j<<(23-k))==iy) yisint = 2-(j&1); - } - } - /* special value of y */ if (__builtin_expect(iy==0x7f800000, 0)) { /* y is +-inf */ if (ix==0x3f800000) @@ -106,6 +91,21 @@ __ieee754_powf(float x, float y) return __ieee754_sqrtf(x); } + /* determine if y is an odd int when x < 0 + * yisint = 0 ... y is not an integer + * yisint = 1 ... y is an odd int + * yisint = 2 ... y is an even int + */ + yisint = 0; + if(hx<0) { + if(iy>=0x4b800000) yisint = 2; /* even integer y */ + else if(iy>=0x3f800000) { + k = (iy>>23)-0x7f; /* exponent */ + j = iy>>(23-k); + if((j<<(23-k))==iy) yisint = 2-(j&1); + } + } + ax = fabsf(x); /* special value of x */ if(__builtin_expect(ix==0x7f800000||ix==0||ix==0x3f800000, 0)){ @@ -131,16 +131,10 @@ __ieee754_powf(float x, float y) if(ix>0x3f800007) return (hy>0)? huge*huge:tiny*tiny; /* now |1-x| is tiny <= 2**-20, suffice to compute log(x) by x-x^2/2+x^3/3-x^4/4 */ - t = ax-1; /* t has 20 trailing zeros */ - w = (t*t)*((float)0.5-t*((float)0.333333333333-t*(float)0.25)); - u = ivln2_h*t; /* ivln2_h has 16 sig. bits */ - v = t*ivln2_l-w*ivln2; - t1 = u+v; - GET_FLOAT_WORD(is,t1); - SET_FLOAT_WORD(t1,is&0xfffff000); - t2 = v-(t1-u); + d2 = ax-1; /* d2 has 20 trailing zeros. */ + d2 = d2 * (ivln2_l + (double)ivln2_h) - + (d2 * d2) * (0.5 - d2 * (0.333333333333 - d2 * 0.25)) * ivln2; } else { - float s2,s_h,s_l,t_h,t_l; /* Avoid internal underflow for tiny y. The exact value of y does not matter if |y| <= 2**-32. */ if (iy < 0x2f800000) @@ -158,69 +152,37 @@ __ieee754_powf(float x, float y) else {k=0;n+=1;ix -= 0x00800000;} SET_FLOAT_WORD(ax,ix); - /* compute s = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */ - u = ax-bp[k]; /* bp[0]=1.0, bp[1]=1.5 */ - v = one/(ax+bp[k]); - s = u*v; - s_h = s; - GET_FLOAT_WORD(is,s_h); - SET_FLOAT_WORD(s_h,is&0xfffff000); - /* t_h=ax+bp[k] High */ - SET_FLOAT_WORD (t_h, - ((((ix>>1)|0x20000000)+0x00400000+(k<<21)) - & 0xfffff000)); - t_l = ax - (t_h-bp[k]); - s_l = v*((u-s_h*t_h)-s_h*t_l); - /* compute log(ax) */ - s2 = s*s; - r = s2*s2*(L1+s2*(L2+s2*(L3+s2*(L4+s2*(L5+s2*L6))))); - r += s_l*(s_h+s); - s2 = s_h*s_h; - t_h = (float)3.0+s2+r; - GET_FLOAT_WORD(is,t_h); - SET_FLOAT_WORD(t_h,is&0xfffff000); - t_l = r-((t_h-(float)3.0)-s2); - /* u+v = s*(1+...) */ - u = s_h*t_h; - v = s_l*t_h+t_l*s; - /* 2/(3log2)*(s+...) */ - p_h = u+v; - GET_FLOAT_WORD(is,p_h); - SET_FLOAT_WORD(p_h,is&0xfffff000); - p_l = v-(p_h-u); - z_h = cp_h*p_h; /* cp_h+cp_l = 2/(3*log2) */ - z_l = cp_l*p_h+p_l*cp+dp_l[k]; - /* log2(ax) = (s+..)*2/(3*log2) = n + dp_h + z_h + z_l */ - t = (float)n; - t1 = (((z_h+z_l)+dp_h[k])+t); - GET_FLOAT_WORD(is,t1); - SET_FLOAT_WORD(t1,is&0xfffff000); - t2 = z_l-(((t1-t)-dp_h[k])-z_h); + /* compute d1 = (x-1)/(x+1) or (x-1.5)/(x+1.5) */ + d1 = (ax-(double)bp[k])/(ax+(double)bp[k]); + /* compute d2 = log(ax) */ + d2 = d1 * d1; + d2 = 3.0 + d2 + d2*d2*(L1+d2*(L2+d2*(L3+d2*(L4+d2*(L5+d2*L6))))); + /* 2/(3log2)*(d2+...) */ + d2 = d1*d2*((double)cp_h + cp_l); + /* log2(ax) = (d2+..)*2/(3*log2) */ + d2 = d2+((double)dp_h[k]+dp_l[k])+(double)n; } s = one; /* s (sign of result -ve**odd) = -1 else = 1 */ if(((((u_int32_t)hx>>31)-1)|(yisint-1))==0) s = -one; /* (-ve)**(odd int) */ - /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */ - GET_FLOAT_WORD(is,y); - SET_FLOAT_WORD(y1,is&0xfffff000); - p_l = (y-y1)*t1+y*t2; - p_h = y1*t1; - z = p_l+p_h; + /* compute y * d2 */ + d1 = y * d2; + z = d1; GET_FLOAT_WORD(j,z); if (__builtin_expect(j>0x43000000, 0)) /* if z > 128 */ return s*huge*huge; /* overflow */ else if (__builtin_expect(j==0x43000000, 0)) { /* if z == 128 */ - if(p_l+ovt>z-p_h) return s*huge*huge; /* overflow */ + if(ovt>(z-d1)) return s*huge*huge; /* overflow */ } else if (__builtin_expect((j&0x7fffffff)>0x43160000, 0))/* z <= -150 */ return s*tiny*tiny; /* underflow */ else if (__builtin_expect((u_int32_t) j==0xc3160000, 0)){/* z == -150*/ - if(p_l<=z-p_h) return s*tiny*tiny; /* underflow */ + if(0.0<=(z-d1)) return s*tiny*tiny; /* underflow */ } /* - * compute 2**(p_h+p_l) + * compute 2**d1 */ i = j&0x7fffffff; k = (i>>23)-0x7f; @@ -228,22 +190,16 @@ __ieee754_powf(float x, float y) if(i>0x3f000000) { /* if |z| > 0.5, set n = [z+0.5] */ n = j+(0x00800000>>(k+1)); k = ((n&0x7fffffff)>>23)-0x7f; /* new k for n */ - SET_FLOAT_WORD(t,n&~(0x007fffff>>k)); + SET_FLOAT_WORD(z,n&~(0x007fffff>>k)); n = ((n&0x007fffff)|0x00800000)>>(23-k); if(j<0) n = -n; - p_h -= t; + d1 -= z; } - t = p_l+p_h; - GET_FLOAT_WORD(is,t); - SET_FLOAT_WORD(t,is&0xfffff000); - u = t*lg2_h; - v = (p_l-(t-p_h))*lg2+t*lg2_l; - z = u+v; - w = v-(z-u); - t = z*z; - t1 = z - t*(P1+t*(P2+t*(P3+t*(P4+t*P5)))); - r = (z*t1)/(t1-two)-(w+z*w); - z = one-(r-z); + d1 = d1 * ((double)lg2_h + lg2_l); + d2 = d1*d1; + d2 = d1 - d2*(P1+d2*(P2+d2*(P3+d2*(P4+d2*P5)))); + d2 = (d1*d2)/(d2-two); + z = one - (d2-d1); GET_FLOAT_WORD(j,z); j += (n<<23); if((j>>23)<=0) /* subnormal output */ -- 1.8.3.1 Regards, PC