From: drh <> Date: Wed, 5 Jul 2023 14:42:50 +0000 (+0000) Subject: Simplification of the dekkerMul2() subroutine. X-Git-Tag: version-3.43.0~157 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1790ccb98ba732d56ea4682c62928615e795480b;p=thirdparty%2Fsqlite.git Simplification of the dekkerMul2() subroutine. FossilOrigin-Name: bfe6432a46fd41bfadf4516a73b4e2523d9b453c3e4486fe6df7e1d25275dfb3 --- diff --git a/manifest b/manifest index d124da2756..ff444b1784 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Add\sthe\sieee754_inc(r,N)\sfunction\sto\sthe\sieee754.c\sextension. -D 2023-07-05T12:00:32.550 +C Simplification\sof\sthe\sdekkerMul2()\ssubroutine. +D 2023-07-05T14:42:50.334 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724 @@ -705,7 +705,7 @@ F src/trigger.c ad6ab9452715fa9a8075442e15196022275b414b9141b566af8cdb7a1605f2b0 F src/update.c 0aa36561167a7c40d01163238c297297962f31a15a8d742216b3c37cdf25f731 F src/upsert.c 5303dc6c518fa7d4b280ec65170f465c7a70b7ac2b22491598f6d0b4875b3145 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0 -F src/util.c 5c6a3c7a88af0cbabb17707314b07f6026410610be73c6b6fba163b1cbf8b5ea +F src/util.c 04958d3937d7db7ae2d0ee18506c384596dfa909cc0c4a1347bf79081c107b5b F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104 F src/vdbe.c 74282a947234513872a83b0bab1b8c644ece64b3e27b053ef17677c8ff9c81e0 F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0 @@ -2043,8 +2043,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0 -P fd987508d5589d42b46625c97cfb2feeac70fdb1cb11224610554b07a60644e6 -R a945cf31e1bc8c6f26ee1341b6778e23 +P 9a36f269451d8832f68e223ac3995493704364e7fd0cc772989c96e863a08d29 +R aad77d965a4f588fb4cf332c1c0a5021 U drh -Z f1876ec8896b7ebc6d97122422450d0a +Z 45d04598133329d93f0fdb912f74ae6c # Remove this line to create a well-formed Fossil manifest. diff --git a/manifest.uuid b/manifest.uuid index cf4f9e757a..df6f400280 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -9a36f269451d8832f68e223ac3995493704364e7fd0cc772989c96e863a08d29 \ No newline at end of file +bfe6432a46fd41bfadf4516a73b4e2523d9b453c3e4486fe6df7e1d25275dfb3 \ No newline at end of file diff --git a/src/util.c b/src/util.c index f14cbf2594..899abce72b 100644 --- a/src/util.c +++ b/src/util.c @@ -386,23 +386,19 @@ u8 sqlite3StrIHash(const char *z){ return h; } -/* Double-Double multiplication. *(z,zz) = (x,xx) * (y,yy) +/* Double-Double multiplication. (x[0],x[1]) *= (y,yy) ** ** Reference: ** T. J. Dekker, "A Floating-Point Technique for Extending the ** Available Precision". 1971-07-26. */ -static void dekkerMul2( - double x, double xx, - double y, double yy, - double *z, double *zz -){ +static void dekkerMul2(double *x, double y, double yy){ double hx, tx, hy, ty, p, q, c, cc; u64 m; - memcpy(&m, &x, 8); + memcpy(&m, &x[0], 8); m &= 0xfffffffffc000000L; memcpy(&hx, &m, 8); - tx = x - hx; + tx = x[0] - hx; memcpy(&m, &y, 8); m &= 0xfffffffffc000000L; memcpy(&hy, &m, 8); @@ -411,9 +407,9 @@ static void dekkerMul2( q = hx*ty + tx*hy; c = p+q; cc = p - c + q + tx*ty; - cc = x*yy + xx*y + cc; - *z = c + cc; - *zz = c - *z + cc; + cc = x[0]*yy + x[1]*y + cc; + x[0] = c + cc; + x[1] = c - x[0] + cc; } /* @@ -587,39 +583,39 @@ do_atof_calc: } *pResult = r; }else{ - double r, rr; + double rr[2]; u64 s2; - r = (double)s; - s2 = (u64)r; - rr = s>=s2 ? (double)(s - s2) : -(double)(s2 - s); + rr[0] = (double)s; + s2 = (u64)rr[0]; + rr[1] = s>=s2 ? (double)(s - s2) : -(double)(s2 - s); if( e>0 ){ while( e>=100 ){ e -= 100; - dekkerMul2(r, rr, 1.0e+100, -1.5902891109759918046e+83, &r, &rr); + dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83); } while( e>=10 ){ e -= 10; - dekkerMul2(r, rr, 1.0e+10, 0.0, &r, &rr); + dekkerMul2(rr, 1.0e+10, 0.0); } while( e>=1 ){ e -= 1; - dekkerMul2(r, rr, 1.0e+01, 0.0, &r, &rr); + dekkerMul2(rr, 1.0e+01, 0.0); } }else{ while( e<=-100 ){ e += 100; - dekkerMul2(r, rr, 1.0e-100, -1.99918998026028836196e-117, &r, &rr); + dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117); } while( e<=-10 ){ e += 10; - dekkerMul2(r,rr, 1.0e-10, -3.6432197315497741579e-27, &r, &rr); + dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27); } while( e<=-1 ){ e += 1; - dekkerMul2(r,rr, 1.0e-01, -5.5511151231257827021e-18, &r, &rr); + dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18); } } - *pResult = r+rr; + *pResult = rr[0]+rr[1]; if( sqlite3IsNaN(*pResult) ) *pResult = 1e300*1e300; } if( sign<0 ) *pResult = -*pResult; @@ -982,35 +978,37 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){ ** ** SELECT decimal_sci(decimal_sub('1.0e+100',decimal(1.0e+100))); */ - double rr = 0.0; - if( r>1.84e+19 ){ - while( r>1.84e+119 ){ + double rr[2]; + rr[0] = r; + rr[1] = 0.0; + if( rr[0]>1.84e+19 ){ + while( rr[0]>1.84e+119 ){ exp += 100; - dekkerMul2(r, rr, 1.0e-100, -1.99918998026028836196e-117, &r, &rr); + dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117); } - while( r>1.84e+29 ){ + while( rr[0]>1.84e+29 ){ exp += 10; - dekkerMul2(r,rr, 1.0e-10, -3.6432197315497741579e-27, &r, &rr); + dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27); } - while( r>1.84e+19 ){ + while( rr[0]>1.84e+19 ){ exp += 1; - dekkerMul2(r,rr, 1.0e-01, -5.5511151231257827021e-18, &r, &rr); + dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18); } }else{ - while( r<1.84e-82 ){ + while( rr[0]<1.84e-82 ){ exp -= 100; - dekkerMul2(r, rr, 1.0e+100, -1.5902891109759918046e+83, &r, &rr); + dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83); } - while( r<1.84e+08 ){ + while( rr[0]<1.84e+08 ){ exp -= 10; - dekkerMul2(r, rr, 1.0e+10, 0.0, &r, &rr); + dekkerMul2(rr, 1.0e+10, 0.0); } - while( r<1.84e+18 ){ + while( rr[0]<1.84e+18 ){ exp -= 1; - dekkerMul2(r, rr, 1.0e+01, 0.0, &r, &rr); + dekkerMul2(rr, 1.0e+01, 0.0); } } - v = rr<0.0 ? (u64)r-(u64)(-rr) : (u64)r+(u64)rr; + v = rr[1]<0.0 ? (u64)rr[0]-(u64)(-rr[1]) : (u64)rr[0]+(u64)rr[1]; }